Instructions for starting asynchronous motors. Production instruction for the operation of electric motors. Types of main faults, their diagnostics and necessary repair of an asynchronous electric motor
1. General part. 1.1. This instruction designed for correct and safe operation, maintenance of AC and DC electric motors of any power. 1.2. When operating electric motors, in addition to this manual, it is necessary to use the regulatory and technical documents listed in Table 1.1. PUE POT RM-0162001 PTEEP IOT R 10-053-04 IOT R 10-202-04 IOT R 10-204-04 Normative and technical documents operation of consumer electrical installations Instruction on labor protection for an electrician for the repair and maintenance of electrical equipment and electrical installations Instruction on labor protection for an electrician for the operation of distribution networks Instruction on labor protection for an electrician for maintenance of substations 1.3. After acceptance of the electric motor (as well as control and start devices, power and control cables of connection related to this electric motor), the operating organization must collect and issue all technical documentation for this electric motor. Each electric motor operating in an explosive zone must have a passport containing all the necessary technical data on the electric motor (passport data), data on repair, testing and measuring explosion protection parameters, data on malfunctions and defects of the electric motor. For electric motors of conventional design, a similar passport is drawn up at a rated voltage of the electric motor of more than 1000V or a unit power of more than 250 kW inclusive. The form of the passport is approved by the person responsible for electrical facilities. The results entered in the passport of the electric motor are also signed by those responsible for the electrical economy. 2. Purpose and technical data. 2.1. The electric motor is designed to convert electrical energy into mechanical. The electric motor is the main element of the electric drive of working machines. 2.2. Each electric motor is characterized by nominal data: Рnom - rated power of the electric motor, kW; Unom - rated voltage of the electric motor, V; Inom - rated current of the electric motor, A; nnom – rated speed, rpm; cosφ - power factor (for AC motors); Efficiency - efficiency;; winding connection - Y (star) ∆ (triangle) (for three-phase AC motors); class of heat resistance of the insulation of the stator windings - F (letter denoting the class); Inom. rotor - rated current of the rotor, A (for DC and AC motors with a phase rotor); operating mode of the electric motor - S + digit indicating the operating mode. 2.3. Electrical insulating materials used in the manufacture of electric motors are divided into seven classes according to heat resistance (the same classes of materials are applicable to other electrical machines). Table 2.1 shows the insulation temperature values depending on the class. In practice, it is forbidden to allow the electric motor (any of its parts) to overheat above 80 ° C, but in emergency modes (when only one electric motor remains in operation from the group, etc. situations), you can focus on the numbers in table 2.1. Limit temperature of windings according to insulation class Heat resistance class Y A E B F Depending on the ambient temperature, the rated power of the electric motor changes, which should be taken into account during operation. Table 2.2 shows the dependence of power on temperature environment. Dependence of the rated power of the electric motor on the ambient temperature Table 2.2 o Ambient temperature, С 40 45 50 55 60 Rated power, % 100 96 92 87 82 2.5. Each electric motor is designed for operation in certain climatic conditions. Table 2.3 shows the linkage of climatic versions of electric motors with the categories of their placement according to environmental parameters. Linkage of climatic versions of electric motors with their placement categories Table 2.3 o Maximum Temperature, C U 4 +35 +1 80 at 25 °C T 2 +50 -10 100 at 35 °C UHL 4 +40 -50 100 at 25 °C CL 1, 2 +40 -60 100 at 25 °C 2.6. Each electric motor can be characterized depending on the degree of protection (the degree of protection of the electric motor is indicated in the passport, or on a special nameplate attached to the electric motor itself). Tables 2.4 and 2.5 provide descriptions and symbols for the degrees of protection. Table 2.5 applies to all types of machines (power transformers, electric motors, etc.). 2.7. The selection and installation of electric motors, ballasts, instrumentation, protection devices, as well as all electrical and auxiliary equipment for them must comply with the requirements of the PUE and environmental conditions. 2.8. When choosing the power of electric motors, it is necessary to take into account the operating conditions of the production mechanism for which the electric motor is intended. The use of electric motors of insufficient power can lead to a disruption in the normal operation of the mechanism, and the use of electric motors of increased power worsens the economic performance of the installation, leads to its rise in cost and increase in power losses. Digits in designation of degrees of protection of electric motors Digit number Digit 0 1 First digit 2 3 4 5 Second digit 0 1 2 3 4 5 6 7 8 Degree of protection No special protection Ingress protection solids more than 50 mm in diameter, accidental touching of current-carrying or moving parts inside the enclosure with a part of the body, such as a hand Protection against the penetration of solid bodies with a diameter of more than 12 mm, no touching of dangerous parts inside the enclosure with fingers Protection against the penetration of tools, wire, etc. diameter or thickness of 2.5 mm Protection against ingress of solid objects larger than 1 mm Protection against dust. Dust inside the shell cannot penetrate in an amount that disrupts the operation of the electric motor. There is no protection. Protection against vertically falling drops of water Protection against drops of water when the shell is tilted up to 15° Protection against rain at an angle of up to 60° Protection against splashes in any direction Protection against water jets in any direction Protection against the effects of sea waves Protection against short-term immersion in water to a certain depth Protection for prolonged immersion in water under conditions specified by the manufacturer Symbols and descriptions of degrees of protection Symbol IP00 IP01 IP10 Table 2.4 Table 2.5 Characteristics of the degree of protection bodies inside the housing, protection against water penetration. A machine protected from drops of water falling vertically on the shell and not having special protection for operating personnel from contact with current-carrying and rotating parts of the machine, protection against ingress of solid bodies into the case Machine protected from penetration into the shell of a large area of the human body surface (for example, a hand ), against the penetration of solid bodies larger than 50 mm, no protection against the ingress of water Symbol IP11 IP12 IP13 IP20 IP21 IP22 IP23 IP43 IP44 IP54 IP55 IP55 Degree of protection characteristic ), against the penetration of solid bodies larger than 50 mm and against drops of water falling vertically on the shell Machine, protected from the penetration into the shell of a large area of the surface of the human body (for example, a hand), from the penetration of solid bodies larger than 50 mm and from drops of water, falling vertically on the shell at inclination of the shell at any angle up to 15° relative to the normal position. Machine protected against penetration into the shell of a large area of the surface of the human body (for example, a hand), from the penetration of solid bodies larger than 50 mm and from drops of water falling on the shell at an angle of 60 ° from the vertical Machine protected from penetration into the shell of fingers or objects long more than 80 mm, against the penetration of solid bodies larger than 12 mm, no protection against the penetration of water The machine is protected against penetration into the shell of fingers or objects longer than 80 mm, against the penetration of solid bodies larger than 12 mm and drops of water falling vertically on the shell Machine , protected from penetration into the shell of fingers or objects longer than 80 mm, from penetration of solid bodies larger than 12 mm and drops of water falling vertically on the shell when the shell is tilted at any angle up to 15 ° relative to the normal position Machine, protected from penetration into the shell of fingers or objects longer than 80 mm, from the penetration of solid bodies larger than 12 mm and drops of water falling on the sheath at an angle of 60° from the vertical Machine protected from penetration into the shell of wire and solid bodies larger than 1 mm and drops of water falling onto the sheath at an angle of 60° from the vertical Machine protected from penetration into the shell sheaths of wire and solids larger than 1 mm and from water splashed onto the sheath in any direction enclosure in any direction A machine that is not completely protected against the ingress of dust into the enclosure (however, dust cannot enter in sufficient quantity to disrupt the operation of the product) and protected from jets of water hitting the enclosure in any direction A machine that is not completely protected from entry into the enclosure dust (however, the dust cannot penetrate in an amount sufficient to disrupt operation and products) and protected from water waves (water does not get inside the shell in an amount sufficient to cause damage during waves) 2. 9. Electric motors are characterized by a certain mode of operation - the order of alternation of periods established by the manufacturer, characterized by the magnitude and duration of the load, shutdowns, braking, starting and reverse during operation. Table 2.6 shows the modes and their characteristics. It is forbidden to operate electric motors (except for urgent need or in emergency situations) in modes of operation that are not typical for them. Modes of operation of electric motors Table 2.6 Mode of operation Characteristics of the mode Mode of operation of the electric motor, when, at a constant rated load Pnom, the operation of the electric motor continues for so long that the overheating temperature of all its parts has time to reach steady state values S1. Distinguish between a continuous mode with a constant load and a long mode with a changing load. The mode of operation of the electric motor, in which periods of constant rated load alternate with periods of shutdown of the electric motor. In this case, the periods of operation are so short that the temperature of all parts of the electric motor does not have time to reach the Short-term steady-state values, and the periods of shutdown of such a mode S2 are long. That all parts of the electric motor have time to reach the ambient temperature. AT symbol the duration of operation of the electric motor is indicated, for example S2-30min (standard: 10; 30; 60 and 90 minutes) The mode of operation of the electric motor, in which short-term modes of operation of the electric motor alternate with periods of its shutdown (pauses), and during the period of operation, the temperature rise does not have time to reach the steady state values, and during the pause period, the parts of the Repeater Electric Motor do not have time to cool down to the temperature of the surrounding short-term medium. The mode is characterized by the relative duration of the th mode S of inclusion in percent: S3-40% - PV = 40% (the electric motor works 40% of the time, 60% rests). It is allowed to transfer the electric motor from the S1 mode to the S3 operating mode, while the electric motor power can be increased: at duty cycle = 60% - by 30%; at PV=40% - by 60%; at PV=25% - by 100% and at PV=15% - by 2.6 times. 3. Device and work. 3.1. An asynchronous electric motor is an AC machine that has a fixed stator with a winding and a rotating rotor, which is performed depending on the design of the electric motor. A characteristic feature of an asynchronous electric motor is the inequality of the frequencies of rotation of the rotor and the rotating field of the stator. 3.2. Structurally asynchronous AC motors Fig. 1 Asynchronous electric motor in section. are divided into two main types: with a phase rotor and with a squirrel-cage rotor. These types of electric motors have the same stator design and differ only in the shape of the rotor. Figure 1 shows the design of an asynchronous motor. Rice. 2 Asynchronous electric motor of the AO series, external view (left) and elements of its design (right). 3.3. Asynchronous machines belong to the category of non-salient-pole machines, since neither the stator nor the rotor of the asynchronous machine has pronounced poles, while the windings (both the stator and the rotor) are evenly distributed in the grooves along the inner perimeter of the stator core and the outer perimeter of the rotor core. 3.4. A DC electric motor by design consists of a stator and a rotor. Its characteristic feature is the presence of a collector and contact brushes of a mechanical AC-to-DC converter. Figure 3 shows a DC motor with its structural details. Rice. 3 Open DC motor in disassembled state. 3.5. DC motors differ in the way of excitation: electric motors can be with independent, parallel, series and mixed excitation, as well as using a permanent magnet. DC motors are reversible machines - the machine can be used as an electric motor and as a generator. 3.6. The principle of operation of asynchronous AC motors and DC motors is the interaction of the magnetic fields of the stator and rotor. In an asynchronous electric motor, a three-phase stator magnetic field induced by a three-phase alternating current creates a magnetic field in the rotor, and, accordingly, a current in its winding, which in turn creates a magnetic field of the rotor. As a result, two magnetic fields, interacting, create a torque. The self-induction EMF in the stator winding acts in the opposite direction of the applied voltage and limits the current through the winding. In a DC electric motor, the torque is created by the constant magnetic field of the stator and armature (rotor). The stator magnetic field is not changeable (constant), the armature magnetic field changes, or is regulated, by changing the armature current. Change settings magnetic field armature and determines the adjustment characteristics of the DC motor. 4. Preparation for work. 4.1. Prior to the operation of the electric motor, the operating personnel (if the electric motor is put into operation by the operating personnel) or the operating and maintenance personnel (if the electric motor is put into operation by the operating and maintenance personnel) must: perform an external inspection of the electric motor and the mechanism driven by it; check the compliance of real starting conditions with nominal starting conditions - check the voltage level on the 0.4 kV buses - the voltage level must be within the nominal limits for this electric motor; check the tightness of all bolted connections; check the reliability of the zeroing circuit for electric motors 0.4 kV; check the protection of the current-carrying parts of the electric motor; check the presence of a guard for rotating parts of the electric motor; check the readiness of circuits and ballasts for electric motors (circuits with switching devices in control circuits must be put into operation); report to the shift supervisor of the ESN of the Ukhtinskaya CS on the readiness of the electric motor for start-up; 4.2. The above procedure for preparing an electric motor for start-up is valid both for newly commissioned electric motors and for electric motors that have been repaired. 4.3. Operational personnel are prohibited from starting the electric motor without an external inspection. 4.4. Electric motors with squirrel-cage rotors are allowed to be started from a cold state 2 times in a row, from a hot state 1 time, if the factory instruction does not allow more starts. Subsequent starts are allowed after the motor has cooled down for a period of time determined by the manufacturer's instructions for this type of motor. 4.5. Repeated switching on of electric motors in case of disconnection by their main protections is allowed after examination and control measurements of insulation resistance. For electric motors of critical mechanisms that do not have a reserve, one repeated switching on after the operation of the main protections is allowed based on the results of an external examination of the motor. Re-starting of electric motors in the event of backup protections is not allowed until the cause of the shutdown is clarified. 4.6. The choice of fusible links for protection against multi-phase short circuits of electric motors of mechanisms with light starting conditions is made according to the formula: I inserts = I starting 2.5 a ) according to the formula: I insert = I starting 1.6 where I insert is the rated current of the fusible insert (A) I insert is the starting current of the electric motor (I insert the starting current for a specific electric motor) = Inom * kstart, where kstart, - coefficient 4.7. Fusible fuse links must be calibrated with an indication of the rated current of the fuse on the stamp. The stamp must be of the manufacturer or electrical laboratory. It is forbidden to use uncalibrated inserts. 4.8. Protection of all elements of the consumer network, as well as technological blocking of nodes, must be carried out in such a way as to ensure self-starting of the electric motors of critical mechanisms. The list of responsible mechanisms involved in self-launching must be approved by the technical manager of the Consumer. Control devices should be located as close as possible to the electric motor in places convenient for maintenance, if other placement is not required due to the conditions of economy, ease of maintenance and cable consumption. If the mechanism driven by it is not visible from the place where the motor control device (button, key, etc.) is installed, and if this mechanism is constantly maintained by personnel, the following must be provided: 1. Alarm or sound notification about the upcoming start of the mechanism. 2. Installation near the electric motor and the driven mechanism of devices for emergency shutdown of the electric motor, excluding the possibility of remote start. If there is control from several places, devices (switches, switches) should be provided that exclude the possibility of remote start of the mechanism or line brought out for repair. 5. Requirements for the safe production of work. 5.1. On electric motors and on the mechanisms driven by them, arrows indicating the direction of rotation of the mechanism and the engine must be applied. On ballasts, the positions "Start" and "Stop" must be marked. When using push-button switching on and off of equipment and mechanisms, the switching buttons must be deepened by 3-5 mm beyond the dimensions of the starting box. contactors, magnetic starters, knife switches, 5.2. Switches, ballasts, etc., as well as fuses, must have inscriptions indicating which electric motor they belong to. 5.3. The terminals of the stator and rotor windings and the cable funnel must be covered with guards. The rotating parts of the machines - pulleys, couplings, fans, open parts of the shafts, must be covered with guards, the removal of which is prohibited during operation of the electric motors. 5.4. Protection of electric motors must be performed in accordance with the PUE. On electric motors that can be systematically overloaded for technical reasons, an overload protection is installed that acts on the signal, automatic unloading of the mechanism or shutdown. When the electric motor of the responsible mechanism is disconnected from the action of protection and there is no backup, it is allowed to restart the electric motor after a thorough check of the control circuit, protection and the electric motor itself. 5.5. Electric motors of mechanisms, the technological process of which is regulated by the stator current, as well as mechanisms subject to technological overload, must be equipped with ammeters installed on the starting board or panel. Ammeters must also be included in the excitation circuits of synchronous motors. On the ammeter scale there should be a red line corresponding to the long-term permissible or nominal value of the stator (rotor) current. On DC motors used to drive critical mechanisms, regardless of their power, the armature current must be controlled. 5.6. Electric motors that are in standby for a long time must be constantly ready for immediate start-up; they must be periodically inspected and tested together with the mechanisms according to a schedule approved by the technical manager of the Consumer. At the same time, for outdoor motors that do not have heating, the insulation resistance of the stator winding and the absorption coefficient should be checked. 5.7. Electric motors must be immediately disconnected from the network in the following cases: in case of accidents with people; the appearance of smoke or fire from the motor housing, as well as from its ballasts; breakdown of the drive mechanism; a sharp increase in the vibration of the mechanism bearings; heating of bearings in excess of the allowable temperature set in the manufacturer's instructions; a significant decrease in the number of revolutions, accompanied by a rapid heating of the electric motor. 5.8. If work on the electric motor or the mechanism driven by it is associated with touching live and rotating parts, the electric motor must be turned off with the implementation of technical measures to prevent its erroneous switching on. In this case, for a two-speed electric motor, both power circuits of the stator windings must be disconnected and disassembled. 5.9. Work that is not related to touching the current-carrying or rotating parts of the electric motor and the mechanism driven by it can be carried out on a running electric motor. It is not allowed to remove the guards of the rotating parts of the operating electric motor and mechanism. 5.10. When working on an electric motor, it is allowed to install grounding on any section of the cable line connecting the electric motor to the switchgear section, shield, assembly. If work on the electric motor is designed for a long period of time, is not performed or is interrupted for several days, then the cable line disconnected from it must also be grounded on the side of the electric motor. In cases where the cross section of the cable cores does not allow the use of portable grounding, for electric motors with voltages up to 1000 V, it is allowed to ground the cable line with a copper conductor with a cross section of at least the cross section of the cable core or connect the cable cores to each other and insulate them. Such grounding or connection of cable cores should be taken into account in operational documentation on a par with portable grounding. 5.11. Before admission to work on electric motors capable of rotation due to the mechanisms connected to them (smoke exhausters, fans, pumps, etc.), the handwheels of stop valves (gate valves, valves, gate valves, etc.) must be locked. In addition, measures have been taken to slow down the rotors of electric motors or disengage the couplings. The necessary operations with shutoff valves must be agreed with the shift supervisor of the technological workshop, section with an entry in the operational log. 5.12. Voltage must be removed from the circuits of manual remote and automatic control of electric drives of shut-off valves, guide vanes. On the handwheels of gate valves, gate valves, valves, posters "Do not open! People are working" should be posted, and on the keys, control buttons for electric drives of shut-off valves - "Do not turn on! People are working." 5.13. On electric motors of the same type or similar in size, installed near the engine on which work is to be done, posters "Stop! Voltage" should be hung out, regardless of whether they are in operation or stopped. 5.14. If it is necessary to carry out testing in the process of work, the procedure for turning on the electric motor (for testing) should be as follows: the foreman removes the team from the place of work, draws up the end of work and hands over the order to the operational personnel. operational personnel removes the installed grounding, posters, assembles the circuit. after testing, if it is necessary to continue working on the electric motor, the operating personnel again prepare workplace and the team along with it is re-admitted to work on the electric motor. 5.15. Work on a rotating electric motor without contact with current-carrying and rotating parts can be carried out by order. 5.16. Maintenance of the brush apparatus on a running electric motor is allowed by order of an employee trained for this purpose, having group 3, subject to the following precautions: work using face and eye protection, in buttoned overalls, being careful not to be caught by the rotating parts of the electric motor. use dielectric galoshes, carpets. do not touch the current-carrying parts of two poles or the current-carrying and grounding parts at the same time. The rotor rings may only be ground while the motor is rotating with pads made of insulating material. 6. Maintenance 6.1. The frequency of maintenance is set depending on the production conditions, but at least 1 time in 2 months. During maintenance, it is necessary to carry out: cleaning of electric motors from contamination (removal of oil, moisture and dust from accessible parts); check the condition of slip rings and brushes for electric motors with a phase rotor; reliability of grounding and connection of electric motors with drive mechanisms; it is necessary to periodically control the operating mode, do not overload the electric motors; serviceable condition of bolted connections of electric motors. 6.2. The frequency of major and current repairs of electric motors is determined by the technical manager of the Consumer. Depending on local conditions, as a rule, current repairs and blowing of electric motors should be carried out simultaneously with the repair of driven mechanisms. 6.3. During TR, the following should be carried out: disassembly of the electric motor, its internal cleaning; replacement of bearing grease, (replacement of grease in bearings under normal operating conditions should be carried out after 4000 hours of operation, but at least once a year). When operating the motor in a dusty and humid environment, the lubricant should be changed more frequently, depending on local conditions; measurement of the insulation resistance of the windings from the housing, if a decrease in the insulation resistance of the stator winding is detected, it is necessary to immediately take measures to restore it in accordance with PTEEP; after assembling the electric motor, a test run is carried out, during which they are convinced that there are no knocks and vibrations, the fan touches the casing 6.4. Overhaul with the excavation of the rotor of electric motors of critical mechanisms operating in severe temperature conditions and with environmental pollution should be carried out at least once every 2 years. 6.5. Preventive tests and measurements on electric motors must be carried out in accordance with the rules for testing electrical equipment. 6.6. To control the presence of voltage on group shields and assemblies of electric motors, voltmeters or signal lamps must be installed. 6.7. To ensure the normal operation of the electric motor, it is necessary to maintain the voltage on the tires in the range from 100 to 105% of the nominal. If necessary, the operation of the electric motor is allowed with a voltage deviation from -5 to + 10% of the nominal. 6.8. Motor vibration measured on each bearing must not exceed the values given in table 2.7. 6.9. Control over the load of electric motors, brush apparatus, vibration, temperature of the elements and cooling media of the electric motor (windings and cores of the stator, air, bearings, etc.), care of bearings (maintaining the required oil level) and cooling air supply devices, as well as operations start and stop of the electric motor must be carried out by the personnel of the unit serving the mechanism. Permissible vibration levels of electric motors rotation speed 3000 1500 1000 Table 2.7 0.05 0.16 Synchronous (rpm) Permissible bearing vibration amplitude, mm 0.10 0.13 750 and below 7. Decommissioning. 7.1. At the end of the service life and dismantling of the electric motor (motors), if it (their) further use at the facilities is impossible, the following measures must be taken: a) disassemble the electric motor (motors) and separate non-ferrous and ferrous metals for subsequent processing or use; b) dispose of the remaining parts of the electric motor (s) in accordance with the instructions for the disposal of this material.
This Standard Instruction is intended to guide the operation of electric motors in auxiliary installations of electric power plants and contains the basic requirements to ensure reliable and safe work electric motors.
The standard instruction applies to asynchronous and synchronous electric motors with a power of over 1 kW, used to drive auxiliary mechanisms of power plants for a voltage of 0.4 kV; 3.15kV; 6.0kV and 10kV, as well as DC motors used to drive fuel feeders, emergency oil pumps for turbines and shaft seals for hydrogen-cooled turbogenerators.
This Standard Instruction is the basis for the preparation of local instructions at each power plant, which must take into account the specific conditions of the operated electric motors, the requirements and recommendations of manufacturers.
Designation: | SO 34.45.509-2005 |
Russian name: | Typical operating instructions for electric motors in auxiliary installations of power plants |
Status: | valid (The term for the first verification of this RM is 2010, the frequency of verification is once every 5 years) |
Replaces: | TI 34-70-023-86 "Typical operating instructions for synchronous electric motors of ball mills Sh-50" (SPO Soyuztekhenergo, 1986) RD 34.45.507 "Typical operating instructions for large electric motors with water-cooled rotor to drive feed pumps" ( SPO Soyuztekhenergo, 1989) RD 34.45.509-91 "Typical operating instructions for electric motors in auxiliary installations of power plants" (SPO ORGRES, 1991) |
Text update date: | 01.10.2008 |
Date added to database: | 01.02.2009 |
Date of entry into force: | 01.09.2005 |
Designed by: | Branch of OJSC "Engineering Center UES" - "Firm ORGRES" 105023, Moscow, Semenovsky per., 15 |
Approved: | Branch of JSC "Engineering Center UES" - "Firm ORGRES" (04.08.2005) |
Published: | TPTI&TO ORGRES No. 2005 |
BRANCH JSC "ENGINEERING CENTER UES" - "FIRMAORGRES"
STANDARD INSTRUCTIONS
ON OPERATION OF ELECTRIC MOTORS IN INSTALLATIONS OF OWN NEEDS OF POWER PLANTS
SO 34.45.509-2005
Moscow 2005
Designed by:Branch of JSC "Engineering Center UES" - "FirmaORGRES"
Executor: V.A. VALITOV
Approved:Chief Engineer of the Branch of JSC Engineering Center UES - Firm ORGRES V.A. KUPCHENKO04.08.2005
The term of the first inspection of this RM is 2010, the frequency of inspection is once every 5 years
Keywords: electric motor, mechanism, insulation, winding, bearing, personnel, maintenance, start-up, shutdown
TYPICAL INSTRUCTIONS FOR OPERATION OF ELECTRIC MOTORS IN POWER PLANTS' OWN NEEDS INSTALLATIONS | SO 34.45.509-2005 |
Coming into effect
from 01.09.2005
This Standard Instruction is intended to guide the operation of electric motors in auxiliary installations of electric power plants and contains the basic requirements to ensure reliable and safe operation of electric motors.
The standard instruction applies to asynchronous and synchronous electric motors with a power of over 1 kW, used to drive auxiliary mechanisms of power plants for a voltage of 0.4 kV; 3.15kV; 6.0 kV and 10 kV, as well as for DC electric motors used to drive fuel feeders, emergency oil pumps for turbines and shaft seals for hydrogen-cooled turbogenerators.
This Standard Instruction is the basis for the preparation of local instructions at each power plant, which must take into account the specific conditions of the operated electric motors, the requirements and recommendations of manufacturers.
With the issuance of this Model Instruction, the following shall cease to be valid:
"Typical instructions for the operation of electric motors in installations for the own needs of power plants: RD34.45.509-91" (M.: SPO ORGRES, 1991);
“Typical operating instructions for large electric motors with water-cooled rotor for driving feed pumps: RD34.45.507” (M.: SPO Soyuztekhenergo, 1989);
"Typical operating instructions for synchronous electric motors of ball mills Sh-50: TI 34-70-023-86" (M.: SPO Soyuztekhenergo, 1986).
1 General requirements
1.1. All electric motors installed in the technological workshops of the power plant must have an abbreviated marking on the body, common with the mechanism and corresponding to the executive working technological scheme, and an indicator of the direction of rotation. Buttons or keys for controlling switches (circuit breakers or magnetic starters) of electric motors must have clear inscriptions indicating which electric motor they refer to, as well as which button or which direction of turning the key refers to starting and which to stopping the electric motor. The marking of switching devices, buttons and control keys must be carried out by the personnel of the electrical department.
The keys of ATS and technological interlocks must have inscriptions indicating their working position (work, automation, reserve, blocked, etc.). On the body of each electric motor there must be a nameplate in accordance with GOST 12969 and GOST 12971 indicating the type, serial number of the machine, trademark, nominal and other technical data.
1.2. An emergency stop button must be located near the installation site of electric motors with remote or automatic control. The emergency button may only be used for emergency stop of the electric motor. Emergency stop buttons must be protected from accidental or erroneous actions and sealed. Control over the safety of the seals should be carried out by the duty personnel of the electrical workshop.
1.3. Electric motors with dual control (local and remote co-operator station APCS) must be equipped with a control type selection switch located at the local push-button control station and signaling the switch position.
1.4. The degree of protection of electric motors of protected design, intended for operation in enclosed spaces without artificial regulation of climatic conditions with dust content of the surrounding air up to 2 mg / m 3, must be at least I P23 according to GOST 17494.
The degree of protection of electric motors of a closed ventilated design, intended for operation in open air and in rooms with high humidity and dust content of the ambient air of not more than 10 mU / m 3, must be at least I P44 according to GOST 17494.
The degree of protection of the output device for both versions of the electric motors must be at least I P54.
Motors and their output devices intended for installation in rooms with increased dust content of the environment, requiring periodic hydro cleaning, must have a degree of protection of at least IP 55.
1.5. Exposed rotating parts (couplings, pulleys, shaft ends, geared belt drives) must be guarded.
1.6. The motor housing and the metal sheath of the supply cable must be reliably grounded with a visible connection between the motor housing and the ground loop. The ground conductor must be welded to the metal base or bolted to the motor frame.
1.7. For AC motors with a power of over 100 kW, if necessary, control technological process, as well as electric motors of mechanisms subject to technological overloads, control of the current stator must be provided. The scale of the device is calibrated in amperes for individual control and as a percentage for a selective control system. On the scale of the ammeter there should be a line corresponding to the rated current of the stator.
On DC motors for driving fuel feeders, emergency oil pumps of turbines and shaft seals of hydrogen-cooled turbogenerators, regardless of their power, the current anchors must be controlled. In cases where information on the SN unit is displayed on the video monitor and operator station of the process control system, the indication of current values of currents that have exceeded the nominal value must differ from the indication of currents in the normal mode of the electric motor.
1.8. Disabled electric motors in reserve must be constantly ready for immediate start. After starting the standby motor, it is necessary to inspect the motor and make sure it is working properly.
1.9. Electric motors that are in the reserve must be put into operation, and those that are in operation must be transferred to the reserve at least once a month according to a schedule approved by the technical manager of the power plant. At the same time, for outdoor motors that do not have heating, the insulation resistance of the stator winding and the absorption coefficient should be checked.
Automatic transfer switch devices (ATS) should be checked at least once a quarter according to the program and schedule approved by the technical manager of the power plant.
1.10. Purged electric motors installed in dusty rooms with high humidity and air temperature, must be equipped with clean cooling air supply devices.
The amount of air blown through the electric motor, as well as its parameters (temperature, impurity content, etc.) must comply with the instructions of the factory technical descriptions and operating instructions.
1.11. Air ducts for supplying and discharging cooling air must be made of non-combustible materials and have a mechanically strong and gas-tight design. Devices for regulating the flow of air and excess air pressure after the final adjustment must be securely fixed and sealed. The tightness of the cooling path (air ducts, connections of air duct casings to the motor housing, dampers) must be checked at least once a year.
1.12. The individual external cooling fan motors shall automatically turn on and off when the main motors are turned on and off.
1.13. The upper points of the water chambers of the air coolers of electric motors must be equipped with cocks to control the complete filling of the air coolers with water.
1.14. On electric motors with forced lubrication of bearings, protection must be installed that acts on the signal and turns off the electric motor when the temperature of the bearing shells rises above the permissible level or the flow stops. lubricants.
1.15. On electric motors with forced ventilation with separately installed fans, protection must be installed that acts on the signal and turns off the electric motor when the temperature of the motor rises above the allowable in the control lyable points or when ventilation is interrupted.
1.16. Electric motors АВ (2АВ)-8000/6000, which were previously used to drive electric feed pumps with water-cooling systems for the rotor winding and active steel of the stator, as well as electric motors with built-in air-water coolers, must be equipped with devices that signal the appearance of water in the housing. In addition, electric motors of the first group must be equipped with protection that acts on the signal when the condensate flow rate through the active parts decreases and on shutdown with a time delay of no more than 3 minutes when the circulation of the cooling medium stops.
The operation of equipment and apparatus of water cooling systems, the quality of condensate in these systems and the cooling water of air coolers must comply with the factory instructions.
1.17. To purge electric motors with compressed air during repairs, air with a pressure of not more than 0.2 MPa (2 kgf / cm 2) should be used. The air must be clean, without moisture and oil. Blowing should be carried out outdoors, if possible, or in a special purge chamber, or dust should be removed with a vacuum cleaner.
1.18. For installation, disassembly and assembly of electric motors, stationary, mobile or inventory hoisting and transport devices must be provided.
1.19. Spare parts for electric motors should be stored in the warehouse of the power plant or repair company and replenished as they are used.
1.20. For each electric motor with a power of 1 kW and above, regardless of the operating voltage, there must be the following technical documentation:
Passport of the electric motor;
Protocol of acceptance tests;
Winding connection diagrams (if they are not standard);
Principal and assembly (executive) schemes of control, signaling and relay protection. In the case of the same type of electric motors, it is allowed to have the indicated diagrams in the documentation of one of the electric motors;
Technical acts on damage to electric motors;
operating log,
1.21. Operational information on the electric motor is entered in the journal (form) by the senior foreman or foreman.
2 Operating conditions and permissible operating modes of electric motors
2.1. To ensure the normal operation of electric motors, the voltage on the auxiliary buses must be maintained at 100-105% of the nominal voltage. If necessary, the operation of electric motors is allowed to maintain the rated power in case of voltage deviations in the network up to ± 10% of the nominal value. The control of the voltage level on the auxiliary buses should be carried out according to measuring instruments(according to the indication on the APCS monitors) installed on control panels (control panel, control panel), as well as devices connected to voltage transformers or directly to the busbars of sections and power assemblies in the premises of switchgear, RUSN, etc.
2.2. When changing the frequency of the supply network within ± 2.5% (1.25 Hz) of the nominal, the operation of the electric motor with the rated load is allowed.
2.3. The rated power of electric motors must be maintained with a simultaneous voltage deviation of up to ± 10% and a frequency of up to ± 2.5% (± 1.25 Hz) of the rated values, provided that when operating with increased voltage and reduced frequency or with reduced voltage and increased frequency, the sum of the absolute values of deviations voltage and frequency does not exceed 10%.
2.4. The voltage on the DC buses feeding the power cabinets of electric motors, control circuits, relay protection devices, alarms and automation under normal operating conditions, is allowed to be maintained 5% higher than the rated voltage of electrical receivers,
2.5. Electric motors must allow direct starting from the full voltage of the network and ensure the start of the mechanism both at the full voltage of the network and at a voltage of at least 80% of the rated voltage during the start-up process. The values of the moments of resistance on the motor shaft during start-ups, as well as the permissible moments of inertia of the driven mechanisms, must be established in the technical specifications for specific types of motors.
2.6. Two-speed electric motors, as a rule, allow direct starting only from a winding of a lower speed, followed by switching (if necessary) to a winding of a higher speed.
The admissibility of direct starting from a winding of a higher speed and the number of such starts are determined by the technical conditions for a specific type of electric motor.
Switching of such motors should be carried out by no more than two switches.
Simultaneous switching on of both windings is not allowed.
The completion of installation and commissioning work must be recorded by the responsible persons of the installation and commissioning organizations in the "Journal of input of equipment from installation", stored on the central control panel.
4.2. During installation and commissioning, as well as upon their completion, the electrical part of the mounted electric motor must undergo node testing and acceptance by the master of the corresponding repair site or ETL group. The end of the node acceptance is recorded in the "Journal of equipment input from installation", after which it is allowed to make a trial run.
4.3. Readiness for a trial run is determined by the management of the electrical department, based on the state of the electric motor and the results of the node acceptance. At his request, the shift supervisor of the electrical shop instructs subordinate personnel to assemble the electrical circuit of the electric motor being tested. Prior to this, the on-duty personnel of the electrical and technological workshops must inspect the electric motor to the extent specified in the paragraphs and this Instruction.
4.4. A trial run of the electric motor must be carried out in the presence of a foreman (engineer) of the electrical workshop, a representative of the installation organization, a foreman and a representative of the technological workshop. A trial run is carried out to determine the direction of rotation (for two-speed electric motors, the direction of rotation is checked at both speeds), mechanical serviceability, correct assembly and installation. The test run is usually carried out with the drive mechanism disengaged and not before full reversal. After trial short-term starts and elimination of the noticed defects, the electric motor is started idle for the time necessary for the bearings to reach the set temperature. At the same time, the vibration state, no-load current, operation of the bearings, and the absence of extraneous sounds should be checked.
4.5. The conduct and results of a test run should be noted by the start-up supervisor in the "Journal of equipment input from installation" and by the duty staff - in operational logs. Subsequent start-ups and assemblies of the electrical circuit can be carried out at the request of the installation, commissioning and operating personnel through the shift supervisor of the technological shop.
4.6. Acceptance of the electric motor into operation is carried out with satisfactory results of complex testing, after which the electric motor is handed over for maintenance to the operating personnel with an entry in the "Journal of commissioning of equipment from installation".
4.7. Testing and running-in of electric motors after overhaul and current repairs is carried out re installation staff after making records of the completion of repair work in the "Journal of input-output of equipment for repair".
4.8. When preparing the electric motor for start-up (for the first time or after repair), the duty personnel of the technological workshop is obliged to check the following:
4.8.1. Completion of all work on the mechanism, closing of orders, absence of people and foreign objects on the unit and inside the fences.
4.8.2. Availability oil in oil baths and its level according to oil gauge in electric motors with plain bearings and annular grease. In electric motors with forced lubrication, readiness for operation oil systems.
4.8.3 Presence of pressure and flow of water through air coolers (and oil coolers when their presence).
4.8.4. Shut-off position and control valves mechanisms, taking into account the instructions point .
4.8.5.Serviceability of sensors alarm devices and technological protections, thermal control devices and technological control(if available).
4.8.6. Reliability fastening of the electric motor and me khanisms, the presence of protective guards for rotating parts and mechanical gears, no clutter service platforms, availability markings on the electric motor.
4.8.7. On electric motors АВ (2АВ)-8000/6000, equipped with systems of direct water cooling of the stator core and rotor winding, as well as units with a forced lubrication system for motor and mechanism bearings, prepare for start-up and commissioning of these systems, ensuring upon completion of repair (installation):
Flushing of pipelines and circuit elements with condensate (oil) in addition to the active parts of the electric motor (bearings);
Filling the systems with clean condensate (oil) by checking the absence of air in the elements of hydraulic circuits;
Alternate short-term testing of pumps during operation at idle with a check of their performance;
Turning on the circulation of condensate (oil) through the active parts of the electric motor (unit bearings) with checking the tightness of the pump check valves and adjusting the flow rate, pressure and temperature of the working medium within the required limits;
Testing (with the involvement of the on-duty staff of the electrical shop and CTAI) ATS of pumps, process signaling devices, interlocks and protections, putting them into operation;
Inspection of systems included in the work for the absence of leaks.
4.8.8. The readiness of the mechanism to start.
4.9. In the absence of comments on the state of the unit, the shift supervisor of the power plant must give the command to the shift supervisor of the electrical shop to assemble the electrical circuit of the electric motor. Upon receipt of such an order, the duty personnel of the electrical workshop must:
4.9.1. Check the completion of work and the closing of all issued orders for work on the electric motor and its electrical equipment. Make sure that there is an extract in the "Journal of input-output of equipment for repair".
4.9.2. Inspect the electric motor, its electrical equipment; check the connection of the supply cables to the motor terminals, the absence of bare current-carrying parts, the density of the outlet device or the closing of the outlet chamber, the serviceability of the starting and switching equipment, the condition of the brush device, the presence and serviceability of the protective grounding of the electric motor.
4.9.3. Make sure that the area around the electric motor and the electric motor itself are free of dirt and foreign objects.
4.9.4. Remove portable grounds or disconnect grounding knives.
4.9.5. Check with a megaohmmeter the integrity of the phases of the stator winding and the supply cable and the condition of the insulation of the windings, which must correspond to the following.
For commissioned for the first time new electric motors and electric motors, undergone rehabilitation or overhaul and reconstruction at a specialized repair shop enterprise, valid values insulation resistance winding st ator, absorption coefficient and non-linearity coefficient, which is the conditions of their inclusions in operation without drying are given in tables 5 and 6.
Insulation resistance of rotor windingssynchronous asynchronous electric motors electric motors with a phase rotor for a voltage of 3 kV or more more than 1 MW, switched on for the first time during operation, should be at least 0.2 MΩ, and after the completion of scheduled repairs it is not standardized.
For electric motorsvoltage above 1kV, which are in operation, the permissible value of the insulation resistance of the winding of the stator R60 and the absorption coefficient at the end of the capital or no ongoing repairs are normalized, but should be taken into account when deciding on the need for their drying. In operation, the determination of the absorption coefficient is mandatory for electric motors with a voltage above 3 kV or a power of more than 1 MW. It should be borne in mind that when the engine is under repair for a long time, its stator winding may be moistened, which may require drying and, for this reason, delay putting it into operation. Therefore, when starting the unit from a scheduled repair, the measurement insulation of the stator winding of electric motors of responsible mechanisms for their own needs should be carried out no later than 2 days. scheduled completion date for repairs. The insulation resistance of the stator windings of electric motors with voltages above 1 kV together with the supply cable, which are started up after a long idle time or being in reserve, is also not standardized. It is considered sufficient if the specified resistance is at least 1 MΩ per 1 kV of the rated linear voltage. Insulation resistance is measured at a nominal winding voltage of up to 0.5 kV inclusive with a mega ohmmeter for a voltage of 500 V, with a rated winding voltage over 0.5 kV to 1 kV - with a mega ohmmeter for a voltage of 1000 V, and with a winding voltage above 1 kV - with a mega ohmmeter for a voltage of 2500 V.
Table5
Permissible values of insulation resistance, absorption coefficients and non-linearity for stator windings, new electric motors put into operation for the first time and electric motors that have undergone restoration or overhaul and reconstruction at a specialized repair company
Power, rated voltage of the electric motor, type of winding insulation | Criteria for assessing the condition of the stator winding insulation |
||||||||||
Insulation resistance value, MΩ | The value of the absorption coefficient R60 ² /R15 ² | Coefficient value nonlinearity ** K u = I nb × U nm / I nm × U nb |
|||||||||
1. Power more than 5 MW, thermosetting and mica compounded insulation | No more than 3 |
||||||||||
2. Power 5mW and below, voltage above 1Kb, thermoset insulation | Not less than 10MΩ per 1kV of rated line voltage at temperature* 10-30°С | Not less than 1.3 at temperature* 10-30°С | |||||||||
3. Electric motors with compounded mica insulation, voltage over 1kV, power from 1 to 5MW inclusive, as well as motors of lower power outdoor installation with the same insulation with voltage over 1kV | Not lower than 1.2 | ||||||||||
4 . Electric motors with micacompounded insulation, voltage over 1kV. power less than 1 MW, except for those specified in paragraph 3 | Not lower than the values indicated in table 6 | ||||||||||
Not lower than 1 Mohm at temperature* 10-30°C | |||||||||||
* At temperatures above 30°С permissible value of insulation resistance decreases 2 times for every 20°C difference between the temperature measured and 30°C, ** U nb - the largest, i.e., the full test rectified voltage (voltage of the last stage); U nm - the smallest test in the rectified (voltage of the first stage); I nb and I nm - leakage currents (I 60 ² ) at stresses U nb and U nm. In order to avoid local overheating of the insulation by leakage currents, voltage exposure at the next stage is allowed only if the leakage currents do not exceed the values indicated below:
|
Table 6
Lowest allowable insulation resistance values for electric motors (see table 5 points 3 and 4)
winding temperature,°C | Insulation resistance R60 ² , MOhm at nominal winding voltage, kV |
||
3-3,15 | 6-6,3 | 10-10,5 |
|
In the event of an unacceptable decrease in insulation resistance and unsatisfactory values of the absorption coefficient and non-linearity, the electric motor must be dried.
4.9.6. Remove safety signs and prohibition warning posters from the electric motor and switching equipment, which was disassembled electrical circuit of the electric motor.
4.9.7. Assemble the electrical circuit of the electric motor and oil lubrication pumps (if any), apply operational current to the control, protection, signaling, automation and blocking circuits. When preparing for the operation of electric motors of ball mills, in addition to assembly electrical circuit synchronous motors and their oil stations, it is necessary to assemble the electrical circuits of their exciters (excitation systems) and fans of the forced cooling system (if the latter are present).
4.9.8. Check the presence and operation of the signal lamps on the control panel, the absence of dropped indicator relays and signals about a malfunction of the circuit and electrical engine, including information about unavailability displayed on the APCS monitor (if available).
4.9.9. Report to the person who gave the order to prepare the electric motor for start-up, to assemble the electrical circuit and motor readiness inclusionto the network. Make a journal entry.
5.1. The inclusion of the electric motor into operation is carried out by the duty personnel of the technological workshop servicing this mechanism. About the upcoming launch of a powerful or a responsible electric motor located in long-term reserve(more than 1 month) or after repair, the workshop personnel servicing the start-up mechanism must notify the electrical workshop personnel, who are obliged to perform pre-start operations according to paragraph 4.9. The exception is launches associated with the liquidation of an emergency, and launches electric motors, switched on by ATS.
5.2. When the electric motor is switched on locally, its control key (button) should be kept in the “Enable” position until the electric motor is turned.
When the electric motor is switched on remotely, its control key (virtual key on the video frame of the technological scheme of the unit being started) should be kept in the "Enable" position until the alarm is activated, indicating the end of the operation being performed (lighting up the signal lamp, light panel, etc.).
5.3. At the place of installation of the electric motor, it is necessary to monitor the starting mode. The observer of the technological workshop must check the correct rotation, ease of movement, and the absence of extraneous noise. In the event of sparks, smoke from the winding or bearings, extraneous sound, knocking and rubbing, you should immediately turn off the electric motor with the emergency button.
In the normal course of the start-up, the supervising person must inspect the electric motor, make sure that the bearings are operating normally, that they do not have unacceptable heating and vibration.
5.4. The person performing the start must observe the start using an ammeter or indication of the stator current on the screen of the operator station of the process control system (if any).
When starting an asynchronous electric motor with a squirrel-cage rotor, the toxator exceeds the nominal value by 5-7 times and remains practically unchanged throughout the entire start. As soon as the rotor speed reaches 90% of the nominal value, the stator current drops sharply to a value close to the nominal value or lower. The start-up time, depending on the flywheel mass of the unit, ranges from several seconds (circulation, feed pumps) to tens of seconds (blowing fans, smoke exhausters).
When starting a synchronous motor of a ball mill, its asynchronous start is initially carried out due to the starting short-circuited winding located in the pole pieces. Upon reaching the subsynchronous frequency of rotation, the motor is automatically excited by supplying direct current to the circuit of the working winding of the rotor, and the electric motor is drawn into synchronism. Signs of draught engine running in synchronism are the presence of the excitation current and the steady position of the ammeter needle in the stator winding circuit.
If the stator current at the end of the start exceeds the nominal value, it is necessary to partially unload the motor in terms of active power and, if necessary, in terms of reactive power (the latter only for synchronous motors when running with a reduced (leading) power factor).
5.5. If at the moment the electric motor is turned on with a voltage above 1000 V, the signal “Earth on the section ...” appears, the electric motor should be turned off and the duty personnel of the electric shop should be informed about this.
5.6. If the engine is turned off during start-up, then it is necessary to confirm the control key, inspect the electric motor and inform the duty personnel of the electrical workshop to take measures to find out the reason for the shutdown and the protection operation.
5.7. Two-speed motors, as a rule, should be connected to the network on a winding of a lower speed, followed by switching (if necessary) to a winding of a higher speed.
The admissibility of direct starting from a winding of a higher rotational speed and the number of such starts are determined by the technical conditions or factory, operating instructions for specific motors.
Simultaneous switching on of both windings is not allowed.
5.8. The start of electric motors that drive fans (smoke exhausters, draft fans, hot blast fans, etc.) must be carried out with closed dampers.
5.9. Electric motors with squirrel-cage rotors are allowed, according to the conditions of their heating, to be started from a cold state 2 times in a row, from a hot state - 1 time, if the factory instruction does not allow more starts. Subsequent starts are allowed after the motor has cooled down for a time determined by the factory instruction.
Subsequent starts of electric motors with voltage over 1000V are allowed after 3 hours.
6 Motor supervision
6.1. Constant supervision of the operation of electric motors should be carried out by the duty personnel of the technological workshop servicing the mechanisms. In addition, the condition and mode of operation of the electric motors should be monitored by the duty personnel of the electrical workshop by periodically scheduling rounds and inspections of all both operating and in reserve electric motors. Regardless of this, all electric motors with a voltage above 1000V at least 2 times a month, and the rest 1 time per month must be inspected by a repairman.
Extraordinary inspections of electric motors must be carried out when they are turned off by protection and a sharp change in climatic conditions (for outdoor units) and operating mode.
6.2. Long-term standby electric motors and automatic transfer devices must be inspected and tested together with the mechanisms according to the schedule approved by the technical manager of the power plant, but at least once a month.
6.3. During the operation of the electric motor, the duty personnel of the technological workshops must:
6.3.1. To regulate the load of electric motors within acceptable limits, depending on the operating mode of the boiler, turbine and other equipment of the power plant, making sure that the stator (rotor) currents do not exceed the nominal values. In the absence of ammeters, control the heating temperature motor directly touching the body with your hand. If the permissible limits for current or heating are exceeded, it is necessary to unload the unit and take measures to find out the cause of the overload.
6.3.2. Control the heating and vibration of the bearings. If an increase in temperature or vibration of the bearing is detected by touch, then it is necessary to carry out a control measurement with a portable device (with lack of stationary appliances).
Ultimately allowed values vibration and temperature bearings of electric motors given in paragraphs and .
6.3.3. Check the oil level in electric motors with ring lubrication of bearings. Plain bearing chambers must be completed oil up to the mark on the oil level indicator or, if there is no mark, to the middle of the oil indicator bearing glasses. If necessary, add oil recommended by the manufacturer brand (T22, T30, Tp30 or other). Frequent topping up (more than 1 time per month) with sees it leaking. Especially dangerous oil leakage inside the housing electric motor, because the it may cause corrosion coverslips, varnishes and reduction of insulation resistance of the stator winding.
AT electric motors with using a forced lubrication system, control the oil pressure in the pressure oil line and the amount of oil on the drain from the bearing, which should fill approximately 1/2 to 1/3 of the cross section of the oil drain line.
6.3.4. Observe the correct operation of the lubrication rings, in particular their rotation. The rapid rotation of the oil rings, accompanied by a slight ringing, indicates a lack of oil in the bearing chamber.
6.3.5. Pay attention to the appearance of abnormal noise in the rolling bearings, indicating insufficient lubrication or the appearance of a defect on the surfaces of the races and rolling elements, and report this to the shift supervisor of the electrical department.
6.3.6. Monitor the heating of the stator using standard heat control sensors. If an increased heating of the winding, core and cooling air is detected, partially unload the motor by stator (rotor) currents and take urgent measures to restore the normal thermal state of the electric motor by regulating the parameters of the cooling water and condensate used to cool the rotor and stator core.
If it is impossible to reduce temperatures to acceptable values, the engine must be stopped by agreement with the shift supervisor of the electrical shop.
6.3.7. Observe the brush apparatus of synchronous electric motors. If unacceptable sparking, increased vibration and other defects are detected, report this to the shift supervisor of the electrical shop to take measures to normalize the operation of the current collection unit.
6.3.8. Control the operation mode of air coolers, as well as direct water cooling systems for electric motors АВ (2АВ)-8000/6000, ensuring that pressures, flow rates and temperatures of cooling water and condensate are maintained within acceptable limits.
6.3.9. Make sure that all rotating parts of the electric motor (terminals, coupling halves, pulleys, etc.) are securely covered with guards.
6.3.10. Do not allow steam, water or oil to enter the motor outlet or inside the motor housing.
6.3.12. Keep records of starts and stops of the electric motor.
6.3.13. Notify the shift supervisor of the electrical shop about all abnormalities in the operation of the electric motor.
6.4. The duty personnel of the electrical workshop, when bypassing and inspecting the electric motor, must control:
Load, housing heating, temperature of the cooling medium, bearing rolling, copper and stator core (without the right to regulate them);
Vibration of bearings and housing (to the touch);
The absence of leaks of air coolers built into the stator and a water supply unit to the active parts of the electric motor inside their housings;
The state of lighting of the service area;
The condition of the grounding of the motor housing;
Condition of the terminal box;
Lack of heating of contact connections and the smell of burnt insulation;
The state of the brush-contact devices of AC motors (in this case, the degree of sparking, heating and vibration of the electric brushes, the force of pressing the brushes to the slip rings, the contamination of the device with brush dust, the presence of hung, extremely worn brushes, as well as brushes with mechanical damage to their fittings, etc.) are controlled.
6.5. If during examinations are detected emergencies and malfunctions in the operation of electric motors, it is necessary to eliminate them, provided that the operations carried out in this case are allowed to be carried out by the production instructions and safety rules solely by this person on duty. Otherwise, it is necessary to immediately inform the higher operational person about the emergency condition and the need to take urgent measures.
A list of the most typical malfunctions of electric motors and methods for their elimination are given in the appendix to this Instruction.
6.6. Switching off the electric motor or changing the mode of its operation is carried out by the duty personnel of the electric shop only with the permission of the shift supervisor of the shop where the electric motor is installed, except in emergency cases (see Section 7).
6.7. All work related to the repair of electric motors is carried out by the repair personnel of the electrical workshop or a specialized repair organization.
Emergency work to eliminate malfunctions of the electric motor that threatens to disrupt the normal operation of the unit (station) is allowed to be performed by the on-duty personnel. At the same time, all organizational and technical measures to prepare the workplace must be completed before work.
7 Emergency motor shutdown
7.1 The electric motor must be immediately (emergency) disconnected from the network under the following circumstances:
Accidents with people;
The appearance of smoke or fire from the housing (output device), bearings, oil lines of the electric motor, its starting and excitatory devices;
Fire at oil pipelines and the impossibility of its liquidation;
Breakage of the driven mechanism;
Failure of technological protections to stop the supply of condensate to the rotor and stator core of electric motors АВ (2АВ)-8000/6000 and an unacceptable decrease in pressure in the bearing lubrication system.
After an emergency shutdown of a running electric motor, measures must be taken to turn on the backup unit and the head of the shift of the technological shop and the head of the shift of the electrical shop should be notified.
7.2 The electric motor must be stopped after starting the electric motor of the standby unit (if any) or after warning the shift supervisor in the following cases:
The appearance of abnormal noise in the electric motor;
The appearance of the smell of burnt insulation;
A sharp increase in the vibration of the electric motor or the mechanism driven by it;
Inadmissible increase in bearing temperature;
Overloading of the electric motor above the permissible limits;
The operation of the electric motor in two phases;
The occurrence of a threat of damage to the electric motor (flooding with water, steaming, etc.).
8 Action of personnel in case of automatic shutdown of the electric motor by protection
8.1. During operation of the electric motor, it may be automatically disconnected from the network by technological or electrical protection.
In case of automatic shutdown of a running electric motor, the duty personnel of the technological workshop must immediately check the successful switching on of the backup unit from the action of the ATS. In case of failure of the ATS or its absence, it is necessary to turn on the electric motor of the backup unit by hand, informing the shift supervisor of the shop in which the electric motor is installed, and the shift supervisor of the electrical shop.
After turning on the electric motor of the standby unit, the duty personnel of the electric shop must, on the switched off electric motor:
Check the absence of signs leading to an emergency shutdown and indicated in;
Find out the cause of the shutdown using the indicator relays and the corresponding alarm;
Perform an external inspection of the switched off electric motor in order to find obvious signs short circuit;
Check the condition of the insulation of the stator winding and the supply cable with a megohmmeter.
The duty personnel of the technological workshop must:
Check the operation of the switched on electric motor;
Monitor the switched on electric motor for 1 hour;
Enter the results of the observation in the operational log.
8.2. Re-starting of electric motors in case of disconnection by their main protection is allowed after examination and control measurements of insulation resistance. If signs of damage to the electric motor or cable are found, its electrical circuit should be disassembled and reported to the shift supervisor of the technological shop, as well as the head of the electrical shop to take measures to replace the damaged electric motor or carry out emergency repairs.
8.3. Emergency shutdown of an electric motor with overload protection, without signs of a short circuit, is possible due to jamming, jamming and other malfunctions of the mechanism. This can be established by measuring the stator current when testing the electric motor under load and at idle without a mechanism (with disengaged coupling halves). In this case, the electric motor can be put into operation only after the personnel of the technological workshop has eliminated the cause of overload and malfunction of the mechanism.
8.4. When the electric motor of the responsible protection mechanism is turned off and there is no backup electric motor, it is allowed to restart the electric motor after an external examination and obtaining permission from the shift supervisor of the electrical shop and the shift supervisor of the station with registration of all instructions and operations in the operational log.
The list of critical mechanisms to which the requirement of this paragraph applies must be approved by the technical manager of the power plant and indicated in the local operating instructions for electric motors.
8.5. Re-starting of electric motors in cases of back-up protection until the cause of the shutdown is clarified is not allowed.
8.6. In case of emergency shutdown of the electric motor as a result of a short circuit in the winding or on its terminals, it may catch fire. Extinguishing the fire of the electric motor should be carried out after disassembling the electrical circuit with a carbon dioxide fire extinguisher or water. It is forbidden to extinguish a burning electric motor with a foam fire extinguisher and sand.
9 Taking the motor out for repair
9.1. No repair work is allowed on a rotating electric motor, except for those that are not related to the approach of live and rotating parts (cleaning, marking, painting, repair of bases and foundations).
9.2. The electric motor is switched off for repairs by the duty personnel of the technological workshop at the direction of the shift supervisor of the workshop with the permission of the station shift supervisor on the basis of the existing application.
During a planned shutdown of the electric motor, the load is reduced, taking into account the instructions of paragraph , the electric motor switch is turned off, the excitation is turned off (for synchronous electric motors), the oil pumps of the forced lubrication system are turned off (after the rotor stops rotating), the water cooling pumps of the active parts of the engines are turned off, water is removed and the cooling system is dried with compressed air (for electric motors type АВ (2АВ)-8000/6000), stopping the supply of cooling water to the air cooler and disassembling the electrical circuits of the electric motor itself and the electric motors of its supporting systems.
During long shutdowns or breaks in operation, if the ambient temperature is below 5ºС, electric heaters must be switched on on the electric motors of the outdoor installation, if they are provided by the manufacturer.
9.3. In the operational journal of the duty personnel, a record should be made about for which work, which workshop and at whose request the electric motor was stopped.
9.4. After turning off the electric motor, the on-duty personnel of the technological workshop must put up a prohibition poster “Do not turn on! People are working." In addition, measures must be taken to prevent the rotation of the electric motor from the side of the mechanism. Such measures include closing the pressure valve, guide vanes, gates, and tying the steering wheels with a lock with a chain, hanging a prohibition poster “Do not open! People are working."
9.5. Until the repair work is completed and the order is closed, the duty personnel of the technological workshop does not have the right to remove these prohibition posters. They must be removed before assembling the electric motor circuit as directed by the shift supervisor of the workshop.
9.6. To carry out repair work on the rotating parts of the mechanism or electric motor or on its current-carrying parts, the duty personnel of the electrical workshop, at the direction of the shift supervisor of the electrical workshop or at the request of the shift supervisor of the station, must take the following measures to prepare the workplace.
9.6.1. Wiring diagram electric motor with a voltage above 1 kV must be disassembled with the creation of a visible gap by rolling out the switchgear trolley to the repair position. Protective curtains must be locked and a prohibition poster “Do not turn on! People are working." A grounding knife must be switched on in the switchgear box.
For a two-speed electric motor, the power supply circuits of the stator windings must be disconnected and disassembled.
9.6.2. The electrical circuit of electric motors with a voltage of 380V connected to the RUSN-0.4kV section must be disassembled by turning off the automatic switch and setting its trolley to the repair position. A prohibition poster “Do not turn on! People are working”, the power cable is disconnected from the motor outputs and a portable ground is installed.
9.6.3. The electrical circuit of electric motors with a voltage of 380V connected to power assemblies must be disassembled by turning off the circuit breaker, a poster “Do not turn it on! People are working." On current-carrying parts after the circuit breaker, the absence of voltage should be checked and the grounding knife turned on, and in its absence, the power cable is disconnected from the motor outputs and a portable ground is installed.
For electric motors of small power, in which the cross section of the supply cable does not allow the installation of portable grounding, it is allowed to ground the cable (with or without disconnection from the motor terminals) with a copper conductor with a cross section of at least the cross section of the cable core or connect the cable cores to each other and insulate them. In this case, twists are allowed.
9.7. At the end of the preparation of jobs in the operational journal of the shift supervisor of the electrical workshop, it should be recorded at whose direction, at the request of which workshop and for what work the electric motor was put out for repair.
9.8. If the power cable of the electric motor of the mechanism being repaired is grounded from the side of the cell or assembly, then the cable must be disconnected from the motor outputs (at the request of the technological workshop) only in cases where movement is required during the repair, or the removal of the electric motor from the foundation is reversed.
As a rule, disconnecting the cables from the outputs of the electric motors should be carried out when the unit or other technological equipment overhaul.
9.9. When the mechanism is stopped only for the repair of the electric motor, disconnecting the cable from the outputs of the electric motor, if grounding is installed on the RUSN side, must be carried out by the personnel repairing the electric motor.
9.10. In all cases, portable grounding must be installed on the disconnected ends of the cable by the on-duty personnel of the electrical workshop.
9.11. After the repair is completed, the connection of the supply cable to the motor terminals, as a rule, must be carried out by the personnel repairing the motor. As an exception, in emergency cases, the connection of the cable is allowed to be carried out by the personnel on duty.
9.12. Repair work on electric motors located on the territory of the technological workshop is carried out according to the orders and orders issued by the electrical workshop from a daily permit. decision of the shift supervisor of the technological shop, who must record this in his operational log. The permission must be transferred by telephone to the duty personnel of the electrical workshop (permitting) and recorded in its operational log.
9.13. During the overhaul and current repairs of the unit, access to work on electric motors located in the premises of the technological workshop and located in the area of the general order must be carried out according to the orders and orders endorsed by the responsible manager in accordance with the general order.
Permission for daily admission from the head of the shift of the technological shop in this case is not required. Admission to work is carried out by the duty personnel of the electrical workshop. The provision of orders and orders for approval to the responsible manager for the general order should be done by the head of work on the order for the repair of the electric motor.
9.14. Testing of control circuits, protection devices and technological interlocks acting on the electric motor switch is allowed to be carried out on the unit being repaired (with the current general order), provided that the switchgear trolley is installed in the test position and there is grounding in the switchgear cell.
9.15. Testing should be carried out at the request of the personnel of the ETL or the thermal automation shop with the permission of the shift supervisor of the technological shop after confirmation by the shift supervisor of the electrical shop that the above testing conditions are met.
9.16. Testing of technological protections and interlocks should be carried out with a minimum number of operations with the switching equipment (to reduce wear, maintain the settings of the switch and the contact block).
9.17. The assembly of the circuit for testing the electric motor is carried out by the duty personnel of the electrical workshop at the request of the work manager with the permission of the shift supervisor of the technological workshop.
9.18. The electric motor being tested is switched on by the on-duty personnel of the process shop at the direction of the shift supervisor of the process shop and at the command of the work manager conducting the testing.
At the time of testing, a prohibitory poster “Do not turn on! People are working” is removed from the switch control key and re-installed at the end of testing.
10 Maintenance, scope of repairs and testing of electric motors.
10.1. Maintenance and repair provide for the implementation of a set of works aimed at ensuring the good condition of electric motors, their reliable, safe and economical operation, carried out with a certain frequency and sequence at optimal labor and material costs.
10.2. Maintenance, which does not require the output of electric motors for current repairs, provides for:
Bypasses according to the schedule and technical inspection of working electric motors;
Control of the technical condition of electric motors using external means of control or diagnostics, including control by portable equipment;
Replenishment and replacement of lubrication of moving parts, cleaning of oil and water filters, tightening of oil seals, checking of control mechanisms, etc.;
Elimination of water, oil leaks and other individual defects identified in the process of monitoring the condition, checking for performance;
Adjustment and blowing of the brush apparatus of synchronous electric motors;
Inspection and verification of electric motors when they are in reserve or on conservation in order to identify and eliminate deviations from the normal state;
Monitoring the serviceability of measuring systems and measuring instruments, including their calibration and other work to maintain the good condition of electric motors;
10.3. At each power plant:
The scope of work on the maintenance of engines and the frequency (schedule) of their implementation for each group of mechanisms is established, taking into account the requirements of the manufacturer and operating conditions;
Responsible executors of maintenance work are appointed or an agreement is concluded with a contractor for the performance of these works;
A system is being introduced to monitor the timely completion and scope of work performed during maintenance;
Maintenance logs (operational logs) are drawn up, in which information about the work performed, deadlines and performers should be entered.
10.4. The frequency and scope of maintenance of electric motors and spare parts for them stored at the power plant is established by power plants in accordance with the instructions for storage and preservation of motors and spare parts for them.
10.5. The type of repair of electric motors is determined by the type of repair of the main equipment, but may differ from it and be determined by the power plant, based on local conditions.
10.6. Overhaul of electric motors, as a rule, is carried out simultaneously with the repair of the mechanism. Combining the terms of repairs of electric motors with mechanisms is advisable in terms of reducing labor costs for work related to centering, preparing the workplace of the unit, etc.
If, due to its technical condition, the electric motor cannot ensure reliable operation until the next overhaul technological unit, the malfunction must be eliminated during the current repair.
When planning the timing of major and current repairs, it is necessary to take into account the technical condition of electric motors, which is established during operation (heating of active parts, vibration, condition of bearings, etc.).
10.7. Schedules and volumes of repairs are approved by the technical manager of the power plant and are binding on the repair personnel. When repairing electric motors by a contractor, schedules and volumes are additionally agreed with the management of the latter.
10.8. All preparatory work must be completed before the motor is taken out for repair:
Long-term and annual plans for preparation for repairs have been developed;
A list of planned work on the repair of electric motors provided for in the annual plan has been prepared;
Compiled and approved technical documentation for modernization or reconstruction works;
Prepared the necessary materials, tools and fixtures;
Lifting mechanisms and rigging devices are brought into line with the rules of Gosgortekhnadzor;
Necessary spare parts are prepared;
Fire fighting and safety measures have been taken.
10.9. The start of the repair of the electric motor is considered to be the time of withdrawal for repair, established by the shift supervisor of the power plant,
10.10. Before stopping the electric motor for repair during its operation under load, operational measurements of the parameters of the electric motors and an assessment of the current state of the engine and its supporting systems are carried out, which are entered in the list of the main parameters of the technical condition of the electric motor, and equipment and service areas are cleaned.
10.11. During the current repair, the following work is performed:
Cleaning and blowing with compressed air;
Checking the air gaps between the stator and the rotor;
Measurement of clearances in plain bearings;
Revision of the terminal box and contact connections;
Revision of the bearing unit, replacement or addition with: strokes.
10.12. The scope of overhaul of the electric motor according to the standard nomenclature includes the following works:
10.12.1. DC motors:
Pre-repair measurements and tests , flaw detection in assembly;
Dismantling from the place of installation and transportation to the workshop;
Examination air gaps between armature and poles;
Disassembly electric motor;
Cleaning and purging with compressed air, as well as with the use of detergents;
Detection wrapped anchor;
Groove and prodorazhivanie collector, checking the quality of soldering windings and core to the collector;
Traverse detection, revision of brush holders, replacement of electric brushes;
Detection of the magnetic system and repair of coils of the main and additional poles;
Detection of the frame and bearing shields;
Revision and replacement of rolling bearings;
Assembly of the electric motor;
Installation at the installation site, alignment with the mechanism;
Measurements and tests after repair.
10.12.2 Asynchronous and synchronous motors:
Pre-repair measurements and tests, complete fault detection;
Dismantling from the installation site and transportation to the workshop;
Checking the air gaps between the armature and the rotor, in plain bearings;
Complete disassembly with rotor output (on site or in the workshop);
Inspection and cleaning of all parts and assemblies;
Checking the density of pressing of the active steel of the stator;
Inspection of welds and fasteners;
Checking the fastening of the stator winding in the slot and frontal parts;
Inspection of connections, terminals of the stator winding and terminal box;
Checking the fastening of the active steel of the rotor, blades and fan hub;
Inspection of the squirrel cage, fans and shrouds of the rotor;
Checking the serviceability of the rods of squirrel-cage rotors and their density in the groove;
Checking the fastening of poles, pole windings and interpole connections of synchronous electric motors;
Checking the integrity of the damper (starting) winding;
Detection of slip rings with their groove and grinding, checking the condition of traverses, brush holders, replacing defective and worn electric brushes;
Checking the fastening of balancing weights; replacement of grease and repair of bearings;
Detection and repair of the thrust bearing (disassembly and cleaning of the oil bath, removal of segments and their supports; checking the condition of fasteners and welds, glasses of support bolts of the stops of the segments; checking the condition of the mirror surface of the disk, the insulating gasket and its tightness along the thrust bearing bush; checking the segments and their supports, scraping them on the calibration plate; installation of segments and adjustment of the load on the segments; replacement of sealing elements, assembly of the oil tank and its sealing);
Audit of the cooling system (dismantling of the air cooler, oil cooler, their disassembly, cleaning and flushing, replacement of gaskets and assembly; hydraulic tests and elimination of detected defects; installation of an oil cooler and its pressure testing with the system; revision, testing with high water pressure of the air cooler and heat exchanger of the water cooling system of the electric motor AB (2AB) -8000/6000, hydraulic testing of the water supply units of the rotor winding and the stator core of these electric motors);
Stator painting;
Assembly of the electric motor;
Electrical measurements and tests after repair.
10.13. After stopping the electric motor for repairs, the personnel of the electrical department must:
Perform all shutdowns that ensure safe working conditions;
Issue a work permit for the repair of an electric motor;
Establish the working hours of support workers (warehouses, laboratories, cranes, etc.).
10.14. During the repair process, the management of the electrical department must:
Carry out incoming quality control of used materials and spare parts;
Carry out operational quality control of the repair work performed;
Check compliance with technological discipline (fulfillment of the requirements of technological documentation, the quality of the devices and tools used).
10.15. During the overhaul of the electric motor, its components can be reconstructed in order to eliminate the shortcomings identified during operation, as well as special work related to the repair or replacement of individual components. Changing the dimensions of parts, replacing components with products of a different type must be agreed with the manufacturer of the electric motor.
10.16. Special work related to the repair of the rotor winding of the istor, with their partial or complete replacement, with the repair of rotor shrouds and reconstruction, are, as a rule, carried out by a repair company.
10.17. Measurement of the vibration of the electric motor (bearings, stator and base plate) should be carried out in the vertical, transverse and axial directions after each scheduled repair, as well as after trimming the bearing shells or replacing them, correcting the alignment, or in case of detecting obvious signs of increased vibration.
10.18. High-voltage electric motors, as well as critical electric motors, regardless of voltage, after installation or overhaul, must be accepted by a commission headed by the management of the electrical shop with the execution of a bilateral act for each electric motor.
Acceptance of the electric motor is carried out partially in accordance with the repair technology - during the assembly process after the repair work has been completed; as a whole - after assembly during testing under load.
10.19. Information about the repair must be entered in the documentation of the electric motor no later than 10 days after the completion of the repair.
10.20. The suitability of the electric motor for operation is determined on the basis of the results of tests carried out in accordance with the requirements of chapters 4 and 5 of the current " Scope and test standards of electrical equipment» and the totality of all tests and inspections carried out.
11 Safety precautions when servicing electric motors. Fire safety.
11.1. basis safe operation electric motors is the fulfillment of the requirements of the current PTE, PTB, PPB, factory instructions for specific types of machines, compliance with permissible operating modes (in terms of load, heating, vibration, lubrication, etc.) and maintenance (inspections, repairs, preventive tests).
11.2. The operational and maintenance of electric motors should be allowed to persons who have been trained, instructed and specially trained to study the principles of operation, device, layout and method of servicing electric motors, who have acquired skills and practical work experience, who have passed exams for knowledge of the rules of technical operation, safety precautions, job and local operating instructions equipment assigned to them.
11.3. Repair and restoration work on a particular electric motor should be carried out, as a rule, on a stopped unit by issuing a work permit.
The admission of repair teams to the place of work is carried out by the duty personnel of the power plant.
11.4. The admission of teams to repair work on the rotating and current-carrying parts of the electric motor should be carried out after the implementation of technical measures, which are described in sufficient detail in Section 11.
11.5. Winding outlets and cable funnels for electric motors must be covered with guards, the removal of which requires unscrewing the nuts or unscrewing the bolts. These guards must not be removed while the motor is running.
11.6. Rotating parts of electric motors and parts connecting electric motors with mechanisms (couplings, pulleys) must be protected from accidental touches.
11.7. With a two-speed motor running, the unused stator winding and the cable supplying it must be considered live.
11.8. When working on the mechanism and the electric motor coupling must be disengaged. The disengagement of the clutch must be carried out by the maintenance personnel along with the repair of the rotating mechanism.
11.9. Before starting work on the electric motor that drives the pump or draft mechanism, measures must be taken to prevent the rotation of the electric motor from the side of the mechanism. Such measures are closing the corresponding valves or gates, locking their handwheels with a lock using chains or other devices and devices. Posters “Do not open! People are working” and “Do not turn on! People are working”, prohibiting the supply of voltage and the operation of stop valves, and at the place of work - a safety sign “Work here!”.
11.10. Work on an electric motor (or a group of electric motors)", from which the supply cable is disconnected, and its ends are short-circuited and grounded, can be carried out without a work order, by order.
The supply of operating voltage to the electric motor before the completion of work (trial switching, testing of the electric motor or its starting device) can be done after the removal of the team, the return of the work order to the operational personnel by the work supervisor and the removal of temporary fences, locking devices and posters.
The work foreman is obliged to warn the workers of his team about the supply of voltage.
The preparation of the workplace and the admission of the brigade after the trial inclusion is carried out as with the initial admission.
11.11. During the repair period, it is forbidden to use flammable detergents to clean metal parts, assemblies and windings with thermosetting insulation from contamination.
11.12. It is forbidden to service electric motors in a women's dress, in raincoats, coats and gowns due to the possibility of being caught by the rotating parts of the specified clothing.
11.13. Maintenance of the brush apparatus with the electric motor running is allowed by order of an employee trained for this purpose with group III electrical safety, subject to the following precautions:
Work with the use of face and eye protection, in buttoned overalls, being careful not to capture it by the rotating parts of the electric motor;
Use dielectric galoshes, carpets;
Do not touch the current-carrying parts of two poles or the current-carrying and grounding parts at the same time.
The rotor rings may only be ground while the motor is rotating with pads made of insulating material.
11.14. It is forbidden to use rubber, polyethylene and other gaskets made of soft and non-oil-resistant material for flange connections of oil lines in the lubrication system of electric motors.
11.15. It is forbidden to carry out work on the oil pipelines and equipment of the oil system during its operation, with the exception of replacing pressure gauges and adding oil.
11.16. Extinguishing a fire in electric motors (after de-energizing them) should be carried out with water, carbon dioxide or bromine ethyl fire extinguishers.
It is not allowed to extinguish a fire in electric motors with foam fire extinguishers or sand.
11.17. If a winding fire inside the motor housing is detected, it must be disconnected from the network, and the excitation is removed on the synchronous motor.
The fired winding of the electric motor can be manually extinguished by personnel through special inspection and technological hatches using mobile fire extinguishing equipment (fire extinguishers, fire nozzles, etc.) after the electric motor is turned off.
12 General guidelines for the preparation of local regulations.
12.1. On the basis of this Model Instruction, a local instruction must be drawn up at each power plant. At the same time, the requirements and recommendations of manufacturers, industry RDs, taking into account operating experience and test results, as well as the specific conditions in which electric motors are operated, must be fully taken into account.
12.2. The local instructions should include those sections and paragraphs of this Standard Instruction that relate to all the main issues of operation of electric motors installed at this power plant, in relation to local conditions.
12.3. The local operating instructions for electric motors must specify:
Permissible conditions and modes of operation of electric motors;
Brief description of the main most powerful electric motors of different voltage classes, their supporting systems (cooling, excitation, lubrication, thermal and technological control and protection devices);
Distribution of responsibilities for the maintenance of electric motors between the workshops of the power plant;
The procedure for preparing for launch, the procedure for starting, shutting down and maintenance during normal operation and in emergency modes;
The procedure for admission to inspection, repair and testing of electric motors;
Safety and fire safety requirements specific to a particular group of electric motors,
12.4. AT job description of each person who is entrusted with the implementation of the requirements of the local instructions for the operation of electric motors, the relevant sections and items to be performed by these persons (electrician on duty, driver on duty, walker on duty, foremen) should be included.
12.5. In the relevant paragraphs of the local instructions, all instructions on the modes, frequency of inspections and control over the operation of electric motors should be given specifically for each type of electric motors in operation. In addition, the frequency of measuring the vibration of the bearings of the responsible mechanisms must be established.
12.6. In the event of a change in the state or operating conditions of electric motors, appropriate additions must be made to the local instructions, bringing them to the attention of employees for whom knowledge of this instruction is mandatory, with an entry in the order log.
12.7. The instruction must be reviewed at least once every 3 years.
12.8. Local instructions for the operation of electric motors must be signed by the head of the electrical department and approved by the technical manager of the power plant.
12.9. In the local operating instructions for electric motors, the list of emergency situations should be specified in accordance with local conditions.
12.10. The local instruction must contain a list of responsible mechanisms approved by the technical manager of the power plant, the re-activation of which after being turned off by their protection is allowed after an external inspection.
12.11. The local operating instructions for electric motors should contain a list of protections, interlocks and alarms.
Application
Typical malfunctions of electric motors and their elimination
p.p. | signs abnormal phenomenon | Likely Causes | ||
At start electric motorbuzzes and does not turn around | Breakage of one phase in the stator circuit (fuse blown, poor contact in the switch, etc.). Breakage or poor contact in the rotor circuit (kink or burnout of the rods in the area of short-circuit rings). | Using a megohmmeter, identify a circuit violation and eliminate it. | ||
Detect cracks or breaks in the rods by measuring the magnetic leakage flux Along the circumference of the rotor using the VAF-85 (see the methodology in EC No. E-11/61 or § 6.60 SDME-81) or in another way. | ||||
The stator winding circuit is assembled incorrectly (“star” instead of “triangle”, one phase is turned out, etc.). Mechanical jamming in the drive mechanism or motor | Check the polarity of the leads (determine the beginnings and ends of each phase) and assemble the stator winding circuit according to the manufacturer's instructions. Bring the unit in for repair and eliminate jamming | |||
Engine emits sparks and smoke when starting or during operation | The grazing of the rotor on the stator due to the ingress of a foreign object into the air gap, excessive wear of the bearings. | Bring the unit in for repair to eliminate the defect. | ||
There was a break in the rod of the short-circuited rotor winding. | Take the engine out for repair. | |||
Interturn short circuit in the stator winding | Troubleshoot winding | |||
Overcurrent protection works at start | Short circuit in the stator circuit (in the cable, in the stator winding, terminal box). | Inspect the entire circuit up to the switching device, measure the insulation resistance of the circuit elements. If a short circuit is found, remove the connection for repair. Change the protection settings according to the motor start detuning conditions. Bring the drive mechanism in for repair | ||
The protection operation current is low or the overcurrent time delay from overload is short. Drive mechanism defective | ||||
Increased bearing vibration | The alignment of the engine with the drive mechanism is broken. | Align the motor with the drive mechanism. | ||
Rotor imbalance, clutch imbalance. | Balance the rotor. Remove the clutch and balance separately from the rotor. Carry out the foundation in accordance with the factory installation requirements. | |||
Insufficient rigidity of the foundation. | ||||
There are gaps between the engine feet and the foundation | Eliminate gaps with gaskets. | |||
The motor feet on the drive side are not pinned and the belleville springs are not installed on the foundation bolts on the side opposite to the drive. | Install pins and cup springs. | |||
The coupling is defective, there are defects in the gear coupling due to incorrect engagement, inappropriate tooth processing. There is a misalignment between the half-couplings mounted on the shafts, one or both half-couplings are beaten, the fingers of the elastic-finger coupling are installed incorrectly or are worn out. | Repair or replace gear coupling. Check the correctness of the nozzle and the runout of both halves of the couplings, check the installation of the fingers in the halves of the couplings. If necessary, eliminate the increased runout of the coupling halves, correct the installation of the fingers or replace them with new ones. | |||
Temperature of oil entering forced lubricated bearings too low | During engine operation, incoming oil should have a temperature of 25-45°C | |||
When the engine is running, rhythmic oscillations of the stator are observed | Contact failure or coil short circuit in the rotor winding | Carry out inspection and necessary repair of the rotor | ||
Water leak from the air cooler, the sensor for monitoring the presence of water in the engine is triggered | Possible cracks in the cooling tube at the flare or weakening of the flare | Remove water from engine. Carry out a hydraulic test of the air cooler to determine the location of the leak. It is allowed to plug one defective tube on both sides with plugs. At more damaged tubes replace the air cooler | ||
Leakage of water in the electric motor АВ(2АВ)-8000/6000 in the weld or in the connection of the "nipple rod" of the rotor | Fistula or fissure formation | Cut out the leak to a depth of 4 mm. Solder with PSR45 solder with PV209X flux. After filling the blank with solder, maintain for 1 min. heating of the neck of the rod to reduce stresses in the “fitting-rod” connection. | ||
in the “rod-short-circuiting ring” connection of the rotor | Same | Cut and remove the technological steel sleeve, cut a groove 5 mm deep around the rod. Solder with PSr45 solder with PV209X flux, maintaining heating of the rod neck during cooling. | ||
through tubes inside the stator core segment | Cracks, fistulas | Exclude a segment from the circuit with a jumper. It is allowed to exclude up to two parallel branches, the distance between which must be at least three packets. In the two extreme branches from each end of the core, segments are not allowed to be excluded. | ||
in collector stator | Loose fittings. | Tighten nuts, tighten. | ||
Loosening of the rubber seals in the end caps. | Tighten flanges or replace rubber seals | |||
Damage to the welds on the manifold. | Weld welds | |||
Contamination of mating sealing surfaces | Thoroughly clean sealing surfaces | |||
Increased leakage of cooling water through the rotor АВ (2АВ)-8000/6000 | PTFE seal wear | Replace bushing | ||
Overheating of the entire stator winding and active steel. Elevated temperature of the cooling air at the outlet of the cooler | Increasing the load more than acceptable. | Reduce the load to nominal and below. | ||
Cooling water temperature increase above normal | Increase the water flow above normal, but no more than twice (at the same time, the pressure in the cooler should not exceed the maximum allowable). | |||
Reducing water consumption | Clean the cooler by removing both covers from it. Rinse tubes with 5% solution of hydrochloric acid and clean with special brushes ("ruffs"). | |||
Clogging of the annulus of the cooler | Check the filters, thoroughly blow the annular space with compressed air | |||
Increasing the water temperature at the outlet of the rotor, stator АВ (2АВ)-8000/6000 | Blockage in the cooling path of the rotor or stator | Carry out reverse washing with water at a temperature of 80-90°C. With a small effect of this method, use chemical reagents (5% hydrochloric acid solution and 5% chromic anhydride solution) | ||
There is no indication of one of the resistance thermocouples | Breakage of the sensor or measuring wiring | Replace the defective converter, eliminate the break or put into operation the spare cable core | ||
Excessive heating of bearings | Insufficient oil supply to the bearings (seized oil ring). Excess or lack of lubrication in rolling bearings. | Increase oil supply to bearings, repair ring failure. Check the quantity and quality of lubricant. If necessary, flush and fill the bearing with the correct amount of grease. | ||
Lubricant or oil contaminated | Clean the oil chambers of the bearings, change the oil. | |||
Wrong brand of oil used. | ||||
Axial impact on the motor rotor from the driven mechanism. | Check the alignment and connection of the motor with the driven machine | |||
No run-up of the rotor | Check the presence of shims between the bearing housing and the shield on the side of the working end of the shaft. | |||
Increased rotor vibration | See paragraph of this table | |||
Oil leakage from bearings | Increased oil consumption through bearings. | Adjust oil flow. | ||
Clogged drain oil pipeline Insufficient sealing of the joints between the labyrinth seals and the bearing housing | Clean the oil drain line. Replace gaskets between labyrinth seals and bearing housing | |||
Reduced stator winding insulation resistance | Dirty or damp winding | Dismantle the motor, blow dry with compressed air, wipe the winding with a cloth moistened with detergent, dry the insulation | ||
Increased brush spark | Insufficient pressing force of the brushes to the slip rings. | Adjust brush pressure. | ||
Contamination or unevenness of the working surfaces of the slip rings. | Polish the working surface of the rings with a fine sandpaper, remove dirt and deposits with a napkin moistened with alcohol. If necessary, grind and grind the rings. | |||
Brushes do not adhere well to slip rings | More carefully grind and grind the brushes to the rings |
List of used literature
Rules for the technical operation of power plants and networks Russian Federation. -M.: SPO ORGRES, 2003.
SO153-34.03.150-2003. Intersectoral rules for labor protection (safety rules) for the operation of electrical installations M .: Publishing house of NTs ENAS, 2003.
SO 34.03.201-97 (RD34.03.201-97). Safety regulations for the operation of thermal mechanical equipment of power plants and heating networks. - M.: Publishing house of NTs ENAS, 2001.
SO 34.03.301-00 (RD153-34.0-03.301-00). Fire safety rules for energy enterprises. - M.: CJSC "Energy Technologies", 2000.
SO34.04.181-2003. Rules for the organization of maintenance and repair of equipment, buildings and structures of power plants and networks M., 2004.
Electrical isolation systems. Evaluation of heat resistance and classification.
GOST9630-80. Three-phase asynchronous motors with voltage over 1000V. General technical conditions.
GOST 51757-2001. Three-phase asynchronous motors with voltage over 1000V for auxiliary mechanisms of thermal power plants. General specifications.
GOST 17494-87. Rotating electrical machines. Classification of the degrees of protection provided by the shells of rotating electrical machines. Notation. Test methods.
GOST 12969-67. Plates for machines and devices. Technical requirements.
GOST 12971-67. Rectangular plates for machines and devices. Dimensions.
Today, the scope of electric motors is very extensive, and one of the most popular and used types of motor is an asynchronous electric motor. But the asynchronous electric motor itself is divided into two types:
- with short-circuited rotor winding (squirrel-cage rotor), phase rotor;
- Schrage-Richter motor (powered from the rotor side).
Application of asynchronous electric motors
Asynchronous motors can operate in two modes of operation: as a generator and as an electric motor. This shows that they can be used as a source of electric current in autonomous mobile power sources.
The use of asynchronous motors as a traction force is more extensive and affects many areas of human life. They have found wide application both in household electrical appliances of low power, and in the technological equipment of enterprises and agriculture.
Types of main faults, their diagnostics and necessary repair of an asynchronous electric motor
Despite the fact that asynchronous motors have high reliability and low manufacturing costs, which led to their popularity, they nevertheless fail. Some malfunctions of electric motors can only be diagnosed on specialized equipment and require repair in a factory for the production and repair of electric motors. However, there are malfunctions that you can diagnose yourself and eliminate which is possible in the conditions of your production.
One of these faults is that the electric motor does not pick up normal speed at start-up or does not rotate. The causes of this malfunction may be electrical or mechanical in nature. Electrical causes include an internal break in the rotor or stator winding, broken connections in the starting equipment, or a break in the supply network. If there is a break in the internal windings of the motor, if they are connected according to the “triangle” scheme, then you must first open them. After that, using a megohmmeter, the phase in which the break occurred is determined. After determining the breakage, the motor winding is rewound and reassembled and installed in place.
Undervoltage in the network, poor contacts in the rotor winding, or high resistance in the rotor circuit of a wound rotor motor causes the motor to rotate at full load below the rated speed. Bad contacts in the winding are detected by applying voltage (20 -25% of the nominal) to the motor stator. At the same time, the locked rotor is turned manually and the current strength in all phases of the stator is checked. In a healthy rotor, the current strength in all positions is the same. In the event that contact is broken in the soldering of the frontal parts, a voltage drop will be noted. The maximum allowable difference in readings should not exceed 10%.
Deployment of the electric motor with an open circuit of the phase rotor. The cause of such a malfunction is a short circuit in the rotor winding. This malfunction is a careful external examination, as well as a measurement of the insulation resistance of the rotor winding. In the event that the inspection does not give results, then it is determined by determining the uneven heating of the rotor winding. In this case, the rotor is braked, and a reduced voltage is applied to the stator.
Uniform heating of the electric motor above the permissible norm occurs due to prolonged overload and deterioration of the cooling system. This fault leads to premature wear of the winding insulation.
Local heating of the stator winding occurs due to a short circuit of the winding to the housing in 2 places, an erroneous connection of the coils in any phase, a short circuit between 2 phases, or a short circuit between the turns of the winding in one of the phases of the stator winding. You can diagnose this malfunction by reducing the speed of rotation of the electric motor, a strong hum or the smell of overheated insulation. Determination of a damaged winding is carried out by measuring the resistance (the damaged phase has less resistance), or by measuring the current strength when a low voltage is applied.
When connecting the windings according to the "star" scheme, the current strength in the damaged phase will be higher than in the rest. In the case of using a "triangle", the line current in the healthy wires will have a higher value.
Burnout or melting of steel that occurs when the stator winding is short-circuited, the steel sheets are short-circuited due to the stator touching the rotor or due to the destruction of the insulation leads to local heating of the active steel of the rotor. In this case, smoke appears, the smell of burning, sparks, the buzz of the engine intensifies. This malfunction occurs due to wear or improper installation of bearings, strong vibration or one-sided attraction of the rotor to the stator (turn shorts in the stator winding).
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BRANCH OF JSC "ENGINEERING CENTER UES" - "FIRM ORGRES"
STANDARD INSTRUCTIONS
ON OPERATION OF ELECTRIC MOTORS IN INSTALLATIONS OF OWN NEEDS OF POWER PLANTS
SO 34.45.509-2005
Moscow 2005
Designed by:Branch of JSC "Engineering Center UES" - "Firm ORGRES"
Executor: V.A. VALITOV
Approved:Chief Engineer of the Branch of JSC Engineering Center UES - Firm ORGRES V.A. KUPCHENKO 04.08.2005
The term of the first inspection of this RM is 2010, the frequency of inspection is once every 5 years
Keywords: electric motor, mechanism, insulation, winding, bearing, personnel, maintenance, start-up, shutdown
TYPICAL INSTRUCTIONS FOR OPERATION OF ELECTRIC MOTORS IN POWER PLANTS' OWN NEEDS INSTALLATIONS |
SO 34.45.509-2005 |
Coming into effect
from 01.09.2005
This Standard Instruction is intended to guide the operation of electric motors in auxiliary installations of electric power plants and contains the basic requirements to ensure reliable and safe operation of electric motors.
The standard instruction applies to asynchronous and synchronous electric motors with a power of over 1 kW, used to drive auxiliary mechanisms of power plants for a voltage of 0.4 kV; 3.15kV; 6.0kV and 10kV, as well as DC motors used to drive fuel feeders, emergency oil pumps for turbines and shaft seals for hydrogen-cooled turbogenerators.
This Standard Instruction is the basis for the preparation of local instructions at each power plant, which must take into account the specific conditions of the operated electric motors, the requirements and recommendations of manufacturers.
With the issuance of this Model Instruction, the following shall cease to be valid:
“Typical instructions for the operation of electric motors in auxiliary installations of power plants: RD 34.45.509-91” (M .: SPO ORGRES, 1991);
“Typical operating instructions for large electric motors with water-cooled rotor for driving feed pumps: RD 34.45.507” (M.: SPO Soyuztekhenergo, 1989);
“Typical operating instructions for synchronous electric motors of ball mills Sh-50: TI 34-70-023-86” (M.: SPO Soyuztekhenergo, 1986).
1 General requirements
1.1. All electric motors installed in the technological workshops of the power plant must have an abbreviated marking on the body, common with the mechanism and corresponding to the executive working technological scheme, and an indicator of the direction of rotation. Buttons or keys for controlling switches (circuit breakers or magnetic starters) of electric motors must have clear inscriptions indicating which electric motor they refer to, as well as which button or which direction of turning the key refers to starting and which to stopping the electric motor. The marking of switching devices, buttons and control keys must be carried out by the personnel of the electrical department.
The keys of ATS and technological interlocks must have inscriptions indicating their working position (work, automation, reserve, blocked, etc.). On the body of each electric motor there must be a nameplate in accordance with GOST 12969 and GOST 12971 indicating the type, serial number of the machine, trademark, nominal and other technical data.
1.2. Near the installation site of electric motors with remote or automatic control, an emergency shutdown button should be located. The emergency button may only be used to stop the motor in an emergency. Emergency stop buttons must be protected from accidental or erroneous actions and sealed. Control over the safety of the seals should be carried out by the duty personnel of the electrical workshop.
1.3. Electric motors with dual control (local and remote from the APCS operator station) must be equipped with a control type selection switch located at the local push-button control station and switch position signaling.
1.4. The degree of protection of electric motors of protected design, intended for operation in enclosed spaces without artificial regulation of climatic conditions with dust content of the surrounding air up to 2 mg / m 3, must be at least IP23 according to GOST 17494.
The degree of protection of electric motors of a closed ventilated design, intended for operation in the open air and in rooms with high humidity and dust content of the ambient air of not more than 10 mU / m 3, must be at least IP44 according to GOST 17494.
The degree of protection of the output device for both versions of electric motors must be at least IP54.
Motors and their output devices intended for installation in rooms with increased dust content of the environment, requiring periodic hydraulic cleaning, must have a degree of protection of at least IP55.
1.5. Exposed rotating parts (couplings, pulleys, shaft ends, belts and gears) must be guarded.
1.6. The motor housing and the metal sheath of the supply cable must be reliably grounded with a visible connection between the motor housing and the ground loop. The ground conductor must be welded to the metal base or bolted to the motor frame.
1.7. For AC motors with a power of more than 100 kW, if it is necessary to control the technological process, as well as electric motors of mechanisms subject to technological overloads, stator current control must be provided. The scale of the device is calibrated in amperes for individual control and in percent for a selective control system. On the scale of the ammeter there should be a line corresponding to the rated current of the stator.
On DC motors for driving fuel feeders, emergency oil pumps of turbines and shaft seals of hydrogen-cooled turbogenerators, regardless of their power, the armature current must be controlled. In cases where information on the MV unit is displayed on the video monitor of the APCS operator station, the indication of current values of currents that have exceeded the nominal value must differ from the indication of currents in the normal mode of the electric motor.
1.8. Disconnected electric motors, which are in reserve, must be constantly ready for immediate start-up. After starting the standby electric motor, it is necessary to inspect the electric motor and make sure that it is operating normally.
1.9. The electric motors that are in the reserve must be put into operation, and the operating ones must be transferred to the reserve at least once a month according to the schedule approved by the technical manager of the power plant. At the same time, for outdoor motors that do not have heating, the insulation resistance of the stator winding and the absorption coefficient should be checked.
Automatic transfer switches (ATS) must be checked at least once a quarter according to the program and schedule approved by the technical manager of the power plant.
1.10. Purged electric motors installed in dusty rooms with high humidity and air temperature, must be equipped with clean cooling air supply devices.
The amount of air blown through the electric motor, as well as its parameters (temperature, impurity content, etc.) must comply with the instructions of the factory technical descriptions and operating instructions.
1.11. Air ducts for supplying and discharging cooling air must be made of non-combustible materials and have a mechanically strong and gas-tight design. Devices for regulating the air flow and excess air pressure after the final adjustment must be securely fastened and sealed. The tightness of the cooling path (air ducts, attachment points of air duct casings to the motor housing, dampers) must be checked at least once a year.
1.12. The individual external cooling fan motors should automatically turn on and off when the main motors are turned on and off.
1.13. The upper points of the water chambers of the air coolers of electric motors must be equipped with cocks to control the complete filling of the air coolers with water.
1.14. On electric motors with forced lubrication of bearings, protection must be installed that acts on the signal and turns off the electric motor when the temperature of the bearing shells rises above the permissible value or the flow stops. lubricants.
1.15. On electric motors with forced ventilation with separately installed fans, protection must be installed that acts on the signal and turns off the electric motor when the motor temperature rises above the allowable in the control points or when ventilation is interrupted.
1.16. AB (2AB)-8000/6000 electric motors, which were previously used to drive electric feed pumps with water cooling systems for the rotor winding and stator active steel, as well as electric motors with built-in air-water coolers, must be equipped with devices that signal the appearance of water in the housing. In addition, electric motors of the first group must be equipped with protection that acts on the signal when the condensate flow rate through the active parts decreases and on shutdown with a time delay of no more than 3 minutes when the circulation of the cooling medium stops.
The operation of equipment and apparatus of water cooling systems, the quality of condensate in these systems and the cooling water of air coolers must comply with the factory instructions.
1.17. To purge electric motors with compressed air during repairs, air with a pressure of not more than 0.2 MPa (2 kgf / cm 2) should be used. The air must be clean, free of moisture and oil. Blowing should be carried out, if possible, outdoors or in a special purge chamber, or dust should be removed with a vacuum cleaner.
1.18. For installation, disassembly and assembly of electric motors, stationary, mobile or inventory lifting and transport devices must be provided.
1.19. Spare parts for electric motors should be stored in the warehouse of the power plant or repair company and replenished as they are used.
1.20. For each electric motor with a power of 1 kW and above, regardless of the operating voltage, there must be the following technical documentation:
Passport of the electric motor;
Protocol of acceptance tests;
Winding connection diagrams (if they are not standard);
Principal and assembly (executive) schemes of control, signaling and relay protection. In the case of the same type of electric motors, it is allowed to have the indicated schemes in the documentation of one of the electric motors;
Technical acts on damage to electric motors;
operating log,
1.21. Operational information on the electric motor is entered into the journal (form) by the senior foreman or foreman.
2 Operating conditions and permissible operating modes of electric motors
2.1. To ensure the normal operation of electric motors, the voltage on the auxiliary buses must be maintained at 100-105% of the nominal voltage. If necessary, the operation of electric motors is allowed with the preservation of the rated power in case of voltage deviations in the network up to ± 10% of the nominal value. The control of the voltage level on the auxiliary buses should be carried out by measuring instruments (by indication on the monitors of the process control system) installed on the control panels (control room, main control room), as well as devices connected to voltage transformers or directly to the busbars of sections and power assemblies in the switchgear rooms , RUSN, etc.
2.2. When the frequency of the supply network changes within ± 2.5% (1.25 Hz) of the nominal one, the operation of the electric motor with the rated load is allowed.
2.3. The rated power of electric motors must be maintained with a simultaneous voltage deviation of up to ± 10% and a frequency of up to ± 2.5% (± 1.25 Hz) of the rated values, provided that when operating with increased voltage and reduced frequency or with reduced voltage and increased frequency, the sum of the absolute values of voltage and frequency deviations do not exceed 10%.
2.4. The voltage on the DC buses feeding the power cabinets of electric motors, control circuits, relay protection devices, alarms and automation under normal operating conditions, can be maintained 5% higher than the rated voltage of power consumers,
2.5. Electric motors must allow direct starting from the full voltage of the network and ensure the start of the mechanism both at the full voltage of the network and at a voltage of at least 80% of the rated voltage during the start-up process. The values of the moments of resistance on the motor shaft during start-ups, as well as the permissible moments of inertia of the driven mechanisms, must be established in the technical specifications for specific types of motors.
2.6. Two-speed electric motors, as a rule, allow direct starting only from a winding of a lower speed, followed by switching (if necessary) to a winding of a higher speed.
The admissibility of direct start from a winding of a higher speed and the number of such starts are determined by the technical specifications for a particular type of electric motor.
Switching of such motors should be carried out by no more than two switches.
Simultaneous switching on of both windings is not allowed.
Completion of installation and commissioning work should be recorded by the responsible persons of the installation and commissioning organizations in the "Journal of Equipment Input from Installation" stored on the central control panel.
4.2. During installation and commissioning, as well as upon their completion, the electrical part of the mounted electric motor must pass unit testing and acceptance by the master of the corresponding repair site or ETL group. The end of the node-by-node acceptance is recorded in the "Journal of equipment input from installation", after which it is allowed to make a trial run.
4.3. Readiness for a trial run is determined by the management of the electrical department, based on the state of the electric motor and the results of the node acceptance. At his request, the shift supervisor of the electrical shop instructs subordinate personnel to assemble the electrical circuit of the electric motor being tested. Prior to this, the duty personnel of the electrical and technological shops must inspect the electric motor to the extent specified in the paragraphs and this Instruction.
4.4. A trial run of the electric motor must be carried out in the presence of a foreman (engineer) of the electrical workshop, a representative of the installation organization, a foreman and a representative of the technological workshop. A trial run is carried out to determine the direction of rotation (for two-speed electric motors, the direction of rotation is checked at both speeds), mechanical serviceability, correct assembly and installation. A test run is usually carried out with the drive mechanism disengaged and not before full turn. After trial short-term starts and elimination of the noticed defects, the electric motor is started idle for the time necessary for the bearings to reach a steady temperature. In this case, the vibration state, no-load current, operation of the bearings, and the absence of extraneous sounds should be checked.
4.5. The conduct and results of a test run should be noted by the start-up manager in the "Journal of equipment commissioning from installation" and by the personnel on duty - in operational logs. Subsequent start-ups and assemblies of the electrical circuit can be carried out at the request of the installation, commissioning and operating personnel through the shift supervisor of the technological shop.
4.6. Acceptance of the electric motor into operation is carried out with satisfactory results of complex testing, after which the electric motor is handed over for maintenance to the operating personnel with an entry in the "Journal of commissioning of equipment from installation".
4.7. Testing and running-in of electric motors after major and current repairs is carried out re installation personnel after making records of the completion of repair work in the "Journal of input-output of equipment for repair".
4.8. When preparing the electric motor for start-up (for the first time or after repair), the duty personnel of the technological workshop must check the following:
4.8.1. Completion of all work on the mechanism, closing of orders, absence of people and foreign objects on the unit and inside the fences.
4.8.2. Availability oil in oil baths and its level according to oil indicator in electric motors with plain bearings and annular grease. For forced lubrication motors, ready for operation oil systems.
4.8.3. Presence of pressure and flow of water through air coolers (and oil coolers when their availability).
4.8.4. Shut-off position and control valves mechanisms, taking into account the instructions point .
4.8.5.Serviceability of sensors alarm devices and technological protections, thermal control devices and technological control(if available).
4.8.6. Reliability fastening of the electric motor and me khanisms, the presence of protective guards for rotating parts and mechanical gears, no clutter service platforms, availability motor markings.
4.8.7. On electric motors АВ (2АВ)-8000/6000, equipped with systems of direct water cooling of the stator core and rotor winding, as well as units with a forced lubrication system for motor and mechanism bearings, prepare for start-up and put into operation of these systems, ensuring upon completion of repair (installation) ):
Flushing of pipelines and circuit elements with condensate (oil) in addition to the active parts of the electric motor (bearings);
Filling the systems with clean condensate (oil) with checking the absence of air in the elements of hydraulic circuits;
Alternate short-term testing of pumps when idling with a check of their performance;
Turning on the circulation of condensate (oil) through the active parts of the electric motor (unit bearings) with checking the tightness of the pump check valves and adjusting the flow rate, pressure and temperature of the working medium within the required limits;
Testing (with the involvement of the on-duty personnel of the electrical shop and CTAI) AVR pumps, process signaling devices, interlocks and protections, putting them into operation;
Inspection of systems included in the work for the absence of leaks.
4.8.8. The readiness of the mechanism to start.
4.9. In the absence of comments on the state of the unit, the shift supervisor of the power plant must give the command to the shift supervisor of the electrical shop to assemble the electrical circuit of the electric motor. Upon receipt of such an order, the duty personnel of the electrical workshop must:
4.9.1. Check the completion of work and the closing of all issued orders for work on the electric motor and its electrical equipment. Make sure that there is an extract in the "Journal of input-output of equipment for repair".
4.9.2. Inspect the electric motor, its electrical equipment; check the connection of the supply cables to the motor terminals, the absence of bare current-carrying parts, the tightness of the output device or the closing of the terminal chamber, the serviceability of the starting and switching equipment, the condition of the brush apparatus, the presence and serviceability of the protective grounding of the motor.
4.9.3. Make sure that the area around the electric motor and the electric motor itself are free of dirt and foreign objects.
4.9.4. Remove portable grounds or disconnect grounding knives.
4.9.5. Check with a megaohmmeter the integrity of the phases of the stator winding and the supply cable and the condition of the insulation windings, which must match the following.
For commissioned for the first time new electric motors and electric motors, undergone rehabilitation or overhaul and reconstruction at a specialized repair enterprise, valid values insulation resistance winding st ator, absorption coefficient and non-linearity coefficient, which is the conditions of their inclusions in operation without drying are given in tables 5 and 6.
Insulation resistance of rotor windingssynchronous electric motors and asynchronous electric motors with a phase rotor for a voltage of 3 kV and above or power more than 1 MW, switched on for the first time into operation, should be at least 0.2 MOhm, and at the end of scheduled repairs it is not standardized.
For electric motorsvoltage above 1 kV, in operation, the permissible value of the insulation resistance of the stator winding R60 and the absorption coefficient at the end of the capital or no ongoing repairs are normalized, but should be taken into account when deciding on the need for their drying. In operation, the determination of the absorption coefficient is mandatory for electric motors with a voltage above 3 kV or a power of more than 1 MW. It should be borne in mind that when the engine is under repair for a long time, its stator winding may be moistened, which may require drying and, for this reason, delay putting it into operation. Therefore, when starting up a unit from a scheduled repair, the measurement insulation of the stator winding of electric motors of responsible mechanisms for their own needs should be carried out no later than 2 days. before the scheduled completion of the repair. The insulation resistance of the stator windings of electric motors with voltages above 1 kV, together with the supply cable, started up after a long idle time or being in reserve, is also not standardized. It is considered sufficient if the specified resistance is at least 1 MΩ per 1 kV of the rated line voltage. Insulation resistance is measured at a rated voltage of the winding up to 0.5 kV inclusive with a mega ohmmeter for a voltage of 500 V, with a rated voltage of the winding over 0.5 kV to 1 kV - with a mega ohmmeter for a voltage of 1000 V, and with a winding voltage above 1 kV - with a mega ohmmeter for a voltage of 2500 V.
Table5
Permissible values of insulation resistance, absorption coefficients and non-linearity for stator windings, new electric motors put into operation for the first time and electric motors that have undergone restoration or overhaul and reconstruction at a specialized repair company
Power, rated voltage of the electric motor, type of winding insulation |
Criteria for assessing the condition of the stator winding insulation |
||||||||||
Insulation resistance value, MΩ |
The value of the absorption coefficient R60 ² /R15 ² |
Coefficient value nonlinearity ** K u = I nb × U nm / I nm × U nb |
|||||||||
1. Power more than 5 MW, thermosetting and mica compounded insulation |
Not less than 10MΩ per 1kV of rated line voltage at temperature* 10-30°С |
No more than 3 |
|||||||||
2. Power 5mW and below, voltage above 1Kb, thermoset insulation |
Not less than 10MΩ per 1kV of rated line voltage at temperature* 10-30°С |
Not less than 1.3 at temperature* 10-30°С |
|||||||||
3. Electric motors with compounded mica insulation, voltage over 1kV, power from 1 to 5MW inclusive, as well as motors of lower power outdoor installation with the same insulation with voltage over 1kV |
Not lower than 1.2 |
||||||||||
4 . Electric motors with micacompounded insulation, voltage over 1kV. power less than 1 MW, except for those specified in paragraph 3 |
Not lower than the values indicated in table 6 |
||||||||||
Not lower than 1 Mohm at temperature* 10-30°C |
|||||||||||
* At temperatures above 30°С permissible value of insulation resistance decreases 2 times for every 20°C difference between the temperature measured and 30°C, ** U nb - the largest, i.e., the full test rectified voltage (voltage of the last stage); U nm - the smallest test in the rectified (voltage of the first stage); I nb and I nm - leakage currents (I 60 ² ) at stresses U nb and U nm. In order to avoid local overheating of the insulation by leakage currents, voltage exposure at the next stage is allowed only if the leakage currents do not exceed the values indicated below:
|
Table 6
Lowest allowable insulation resistance values for electric motors (see table 5 points 3 and 4)
winding temperature,°C |
Insulation resistance R60 ² , MOhm at nominal winding voltage, kV |
||
3-3,15 |
6-6,3 |
10-10,5 |
|
In the event of an unacceptable decrease in the insulation resistance and unsatisfactory values of the absorption coefficient and non-linearity, the electric motor must be dried.
4.9.6. Remove safety signs and prohibition warning posters from the electric motor and switching equipment, which was used to disassemble the electrical circuit of the electric motor.
4.9.7. Assemble the electrical circuit of the electric motor and lubrication oil pumps (if any), apply operational current to the control, protection, signaling, automation and blocking circuits. When preparing for the operation of electric motors of ball mills, in addition to assembling electrical circuit synchronous motors and their oil station, it is necessary to assemble the electrical circuits of their exciters (excitation systems) and fans of the forced cooling system (if any).
4.9.8. Check the presence and operation of signal lamps on the control panel, the absence of dropped indicator relays and signals about a malfunction of the circuit and electrical engine, including information about unavailability displayed on the APCS monitor (if available).
4.9.9. Report to the person who gave the order to prepare the electric motor for start-up, to assemble the electrical circuit and motor readiness to inclusionto the network. Make an entry in the journal.
5.1. The inclusion of the electric motor into operation is carried out by the duty personnel of the technological workshop servicing this mechanism. About the upcoming launch of a powerful or a responsible electric motor located in long-term reserve(more than 1 month) or after repair, the workshop personnel servicing the triggered mechanism must notify the electrical workshop personnel, who are obliged to perform pre-start operations in accordance with paragraph 4.9. The exceptions are launches associated with the liquidation of an emergency situation, and launches electric motors, switched on by AVR.
5.2. When the electric motor is switched on locally, its control key (button) should be kept in the “Enable” position until the electric motor is turned.
When the electric motor is switched on remotely, its control key (virtual key on the video frame of the technological scheme of the unit being started) should be kept in the "Enable" position until the alarm is activated, indicating the end of the operation being performed (lighting of the signal lamp, light panel, etc.).
5.3. At the place of installation of the electric motor, it is necessary to monitor the starting mode. The observing person of the technological workshop must check the correct rotation, ease of movement, and the absence of extraneous noise. In the event of sparks, smoke from the winding or bearings, extraneous sound, knocking and rubbing, you should immediately turn off the electric motor with an emergency button.
In the normal course of the start-up, the observing person must inspect the electric motor, make sure that the bearings are operating normally, that they do not have unacceptable heating and vibration.
5.4. The person performing the start must observe the start using an ammeter or stator current indication on the screen of the APCS operator station (if any).
When starting an asynchronous electric motor with a squirrel-cage rotor, the stator current exceeds the nominal value by 5-7 times and remains practically unchanged throughout the entire start. As soon as the rotor speed reaches 90% of the nominal value, the stator current drops sharply to a value close to the nominal value or lower. The start-up time, depending on the swing masses of the unit, ranges from several seconds (circulation, feed pumps) to tens of seconds (blower fans, smoke exhausters).
When starting a synchronous motor of a ball mill, its asynchronous start is initially carried out due to the starting short-circuited winding located in the pole pieces. Upon reaching the subsynchronous speed, the motor is automatically excited by supplying direct current to the circuit of the working winding of the rotor, and the electric motor is drawn into synchronism. Signs of draught engine running in synchronism are the presence of the excitation current and the steady position of the ammeter needle in the stator winding circuit.
If the stator current at the end of the start exceeds the nominal value, it is necessary to partially unload the motor in terms of active power and, if necessary, in reactive power (the latter only for synchronous motors when operating with a reduced (leading) power factor).
5.5. If at the moment the electric motor is turned on with a voltage above 1000V, the signal “Earth on the section ...” appears, the electric motor should be turned off and the duty personnel of the electrical shop should be informed about this.
5.6. If the engine is turned off during start-up, then it is necessary to acknowledge the control key, inspect the electric motor and inform the duty personnel of the electrical shop to take measures to find out the reason for the shutdown and the protection operation.
5.7. Two-speed motors, as a rule, should be connected to the network on a winding of a lower speed, followed by switching (if necessary) to a winding of a higher speed.
The admissibility of direct starting from a winding of a higher rotational speed and the number of such starts are determined by the technical conditions or factory, operating instructions for specific motors.
Simultaneous switching on of both windings is not allowed.
5.8. The start of electric motors that drive fans (smoke exhausters, draft fans, hot blast fans, etc.) must be carried out with closed dampers.
5.9. Electric motors with squirrel-cage rotors are allowed, according to the conditions of their heating, to be started from a cold state 2 times in a row, from a hot state - 1 time, if the factory instruction does not allow more starts. Subsequent starts are allowed after the motor has cooled down for a time specified in the manufacturer's instructions.
Subsequent starts of electric motors with voltage over 1000V are allowed after 3 hours.
6 Motor supervision
6.1. Constant supervision of the operation of electric motors should be carried out by the duty personnel of the technological workshop servicing the mechanisms. In addition, the condition and mode of operation of the electric motors should be monitored by the on-duty personnel of the electrical workshop by periodically scheduled rounds and inspections of all both operating and standby electric motors. Regardless of this, all electric motors with voltages above 1000V at least 2 times a month, and the rest 1 time per month must be inspected by a repairman.
Unscheduled inspections of electric motors must be carried out when they are turned off by protection and a sharp change in climatic conditions (for outdoor units) and operating mode.
6.2. Long-term standby electric motors and automatic transfer switch devices must be inspected and tested together with the mechanisms according to the schedule approved by the technical manager of the power plant, but at least once a month.
6.3. During the operation of the electric motor, the duty personnel of the technological workshops must:
6.3.1. To regulate the load of electric motors within acceptable limits, depending on the operating mode of the boiler, turbine and other equipment of the power plant, making sure that the stator (rotor) currents do not exceed the nominal values. In the absence of ammeters, control the heating temperature motor directly by touching the body with your hand. If the permissible limits for current or heating are exceeded, it is necessary to unload the unit and take measures to find out the cause of the overload.
6.3.2. Control the heating and vibration of the bearings. If an increase in temperature or vibration of the bearing is detected by touch, it is necessary to take a control measurement with a portable device (with lack of stationary appliances).
Ultimately allowed values vibration and temperature electric motor bearings given in paragraphs and .
6.3.3. Check the oil level in electric motors with ring lubrication of bearings. Plain bearing chambers must be filled oil to the mark on the oil dipstick or, if there is no mark, to the middle of the oil indicator bearing glasses. Top up oil if necessary recommended by the manufacturer brand (T22, T30, Tp30 or other). Frequent topping up (more than once a month) with indicates a leak. Especially dangerous oil leakage inside the housing electric motor, because the it can cause corrosion covers, varnishes and reduction of the insulation resistance of the stator winding.
AT electric motors with using a forced lubrication system, control the oil pressure in the pressure oil line and the amount of oil at the outlet from the bearing, which should fill approximately from 1/2 to 1/3 of the cross section of the oil drain line.
6.3.4. Observe the correct operation of the oil rings, in particular their rotation. The rapid rotation of the oil rings, accompanied by a slight ringing, indicates a lack of oil in the bearing chamber.
6.3.5. Pay attention to the appearance of abnormal noise in the rolling bearings, indicating insufficient lubrication or the appearance of a defect on the surfaces of the races and rolling elements, and report this to the shift supervisor of the electrical department.
6.3.6. Monitor the heating of the stator using standard heat control sensors. If an increased heating of the winding, core and cooling air is detected, partially unload the motor by stator (rotor) currents and take urgent measures to restore the normal thermal state of the electric motor by regulating the parameters of the cooling water and condensate used to cool the rotor and stator core.
If it is impossible to reduce temperatures to acceptable values, the engine must be stopped in agreement with the shift supervisor of the electrical department.
6.3.7. Observe the brush apparatus of synchronous electric motors. If unacceptable sparking, increased vibration and other defects are detected, inform the shift supervisor of the electrical shop about this in order to take measures to normalize the operation of the current collection unit.
6.3.8. Control the operation mode of air coolers, as well as direct water cooling systems for electric motors АВ (2АВ)-8000/6000, ensuring that pressures, flow rates and temperatures of cooling water and condensate are maintained within acceptable limits.
6.3.9. Ensure that all rotating parts of the electric motor (shaft ends, coupling halves, pulleys, etc.) are securely covered with guards.
6.3.10. Do not allow steam, water or oil to enter the motor outlet or inside the motor housing.
6.3.12. Keep records of starts and stops of the electric motor.
6.3.13. Notify the shift supervisor of the electrical department of all abnormalities in the operation of the electric motor.
6.4. The duty personnel of the electrical workshop, when bypassing and inspecting the electric motor, must control:
Load, housing heating, temperature of the cooling medium, rolling bearings, copper and stator core (without the right to regulate them);
Vibration of bearings and housing (to the touch);
No leaks of air coolers built into the stator and water supply units to the active parts of the electric motor inside their housings;
The state of lighting of the service area;
The condition of the grounding of the motor housing;
Condition of the terminal box;
Lack of heating of contact connections and the smell of burnt insulation;
The state of brush-contact devices of AC electric motors (at the same time, the degree of sparking, heating and vibration of the electric brushes, the efforts of pressing the brushes to the slip rings, the contamination of the device with brush dust, the presence of hung, extremely worn brushes, as well as brushes with mechanical damage to their fittings, etc. are controlled. ).
6.5. If during inspections emergencies and malfunctions in the operation of electric motors are detected, it is necessary to eliminate them, provided that the operations carried out in this case are allowed to be carried out by production instructions and safety regulations solely by this person on duty. Otherwise, it is necessary to immediately inform the superior operational person about the emergency condition and the need to take urgent measures.
The list of the most typical malfunctions of electric motors and methods for their elimination are given in the appendix to this Instruction.
6.6. Switching off the electric motor or changing the mode of its operation is carried out by the duty personnel of the electric shop only with the permission of the shift supervisor of the shop where the electric motor is installed, except in emergency cases (see Section 7).
6.7. All work related to the repair of electric motors is carried out by the repair personnel of the electrical workshop or a specialized repair organization.
Emergency work to eliminate malfunctions of the electric motor that threatens to disrupt the normal operation of the unit (station) is allowed to be performed by the on-duty personnel. At the same time, all organizational and technical measures to prepare the workplace must be completed before work.
7 Emergency motor shutdown
7.1 The electric motor must be immediately (emergency) disconnected from the network under the following circumstances:
Accidents with people;
The appearance of smoke or fire from the housing (output device), bearings, oil lines of the electric motor, its starting and excitatory devices;
Fire at oil pipelines and the impossibility of its liquidation;
Breakage of the driven mechanism;
Failure of technological protections to stop the supply of condensate to the rotor and stator core of electric motors АВ (2АВ)-8000/6000 and an unacceptable decrease in pressure in the bearing lubrication system.
After an emergency shutdown of a running electric motor, measures must be taken to turn on the backup unit and the shift supervisor of the technological shop and the shift supervisor of the electrical shop should be informed.
7.2 The electric motor must be stopped after starting the electric motor of the standby unit (if any) or after warning the shift supervisor in the following cases:
The appearance of abnormal noise in the electric motor;
The appearance of the smell of burnt insulation;
A sharp increase in the vibration of the electric motor or the mechanism driven by it;
Inadmissible increase in bearing temperature;
Overloading of the electric motor above the permissible limits;
The operation of the electric motor in two phases;
The occurrence of a threat of damage to the electric motor (filling with water, steaming, etc.).
8 Personnel action during automatic shutdown of the electric motor by protection
8.1. During operation of the electric motor, it may be automatically disconnected from the network by technological or electrical protection.
In case of automatic shutdown of a running electric motor, the duty personnel of the technological workshop must immediately check the successful switching on of the standby unit from the action of the ATS. In case of failure of the ATS or its absence, it is necessary to turn on the electric motor of the backup unit by hand, informing the shift supervisor of the shop in which the electric motor is installed, and the shift supervisor of the electrical shop.
After turning on the electric motor of the standby unit, the duty personnel of the electric shop must, on the switched off electric motor:
Check the absence of signs leading to an emergency shutdown and indicated in;
Find out the reason for the shutdown using the indicator relays and the corresponding alarm;
Perform an external inspection of the switched off electric motor in order to find obvious signs of a short circuit;
Check the condition of the insulation of the stator winding and the supply cable with a megohmmeter.
The duty personnel of the technological workshop must:
Check the operation of the switched on electric motor;
Monitor the switched on electric motor for 1 hour;
Enter the results of the observation in the operational log.
8.2. Re-starting of electric motors in case of disconnection by their main protections is allowed after examination and control measurements of insulation resistance. If signs of damage to the electric motor or cable are found, its electrical circuit should be disassembled and reported to the shift supervisor of the technological shop, as well as the head of the electrical shop to take measures to replace the damaged electric motor or carry out emergency repairs.
8.3. Emergency shutdown of an electric motor with overload protection, without signs of a short circuit, is possible due to jamming, jamming and other malfunctions of the mechanism. This can be established by measuring the stator current when testing the electric motor under load and at idle without a mechanism (with disengaged coupling halves). In this case, the electric motor can be put into operation only after the personnel of the technological workshop has eliminated the cause of overload and malfunction of the mechanism.
8.4. When the electric motor of the responsible mechanism is disconnected from the protection action and there is no backup electric motor, it is allowed to restart the electric motor after an external examination and obtaining permission from the shift supervisor of the electrical shop and the shift supervisor of the station with registration of all instructions and operations in the operational log.
The list of critical mechanisms that are subject to the requirement of this paragraph must be approved by the technical manager of the power plant and indicated in the local operating instructions for electric motors.
8.5. Re-enabling electric motors in cases of back-up protection until the cause of the shutdown is clarified is not allowed.
8.6. In case of emergency shutdown of the electric motor as a result of a short circuit in the winding or on its terminals, it may catch fire. Extinguishing the fire of the electric motor should be carried out after disassembling the electrical circuit with a carbon dioxide fire extinguisher or water. It is forbidden to extinguish a burning electric motor with a foam fire extinguisher and sand.
9 Taking the motor out for repair
9.1. On a rotating electric motor, no repairs are allowed, except for those that are not related to approaching live and rotating parts (cleaning, marking, painting, repairing bases and foundations).
9.2. The electric motor is switched off for repairs by the duty personnel of the technological shop at the direction of the shop shift supervisor with the permission of the station shift supervisor based on the existing application.
During a planned shutdown of the electric motor, the load is reduced, taking into account the instructions of paragraph , the electric motor switch is turned off, the excitation is turned off (for synchronous electric motors), the oil pumps of the forced lubrication system are turned off (after the rotor stops rotating), the water cooling pumps of the active parts of the engines are turned off, water is removed and the cooling system is dried compressed air (for electric motors type AB (2AB) -8000/6000), stopping the supply of cooling water to the air cooler and disassembling the electrical circuits of the electric motor itself and the electric motors of its supporting systems.
During long shutdowns or interruptions in operation, if the ambient temperature is below 5ºС, electric heaters must be switched on on the electric motors of the outdoor installation, if they are provided by the manufacturer.
9.3. An entry should be made in the operational log of the duty personnel for which work, which workshop and at whose request the electric motor was stopped.
9.4. After turning off the electric motor, the on-duty personnel of the technological workshop should put up a prohibition poster “Do not turn on! People are working." In addition, measures must be taken to prevent the rotation of the electric motor from the side of the mechanism. Such measures are closing the pressure valve, guide vanes, gates, and tying the steering wheels with a chain with locking, hanging a prohibition poster “Do not open! People are working."
9.5. Until the repair work is completed and the order is closed, the duty personnel of the technological workshop does not have the right to remove these prohibition posters. They must be removed before assembling the electric motor circuit as directed by the shop shift supervisor.
9.6. To carry out repair work on the rotating parts of the mechanism or electric motor or on its current-carrying parts, the duty personnel of the electrical workshop, at the direction of the shift supervisor of the electrical workshop or at the request of the shift supervisor of the station, must take the following measures to prepare the workplace.
9.6.1. The electrical circuit of the electric motor with a voltage above 1 kV must be disassembled with the creation of a visible break by rolling out the switchgear trolley to the repair position. Protective curtains must be locked and a prohibition poster “Do not turn on! People are working." A grounding knife must be switched on in the switchgear cubicle.
For a two-speed electric motor, both power circuits of the stator windings must be disconnected and disassembled.
9.6.2. The electrical circuit of 380V electric motors connected to the RUSN-0.4kV section must be disassembled by turning off the automatic switch and setting its trolley to the repair position. A prohibitory poster “Do not turn on! People are working”, the power cable is disconnected from the motor outputs and a portable ground is installed.
9.6.3. The electrical circuit of electric motors with a voltage of 380V connected to power assemblies must be disassembled by turning off the automatic switch, a poster “Do not turn on! People are working." On current-carrying parts after the circuit breaker, the absence of voltage should be checked and the grounding knife turned on, and in its absence, the power cable is disconnected from the motor terminals and a portable ground is installed.
For electric motors of small power, in which the cross section of the supply cable does not allow the installation of portable grounding, it is allowed to ground the cable (with or without disconnection from the motor terminals) with a copper conductor with a cross section of at least the cross section of the cable core or connect the cable cores to each other and insulate them. In this case, twists are allowed.
9.7. At the end of the preparation of jobs in the operational journal of the shift supervisor of the electrical workshop, it should be recorded at whose direction, at the request of which workshop and for what work the electric motor was put out for repair.
9.8. If the power cable of the electric motor of the repaired mechanism is grounded from the side of the cell or assembly, then disconnecting the cable from the motor terminals (at the request of the technological workshop) should be carried out only in those cases when during the repair it is required to move, turn or remove the electric motor from the foundation.
As a rule, disconnection of cables from the outputs of electric motors should be carried out when the unit or other process equipment is taken out for major repairs.
9.9. When the mechanism is stopped only for the repair of the electric motor, disconnecting the cable from the outputs of the electric motor, if grounding is installed on the RUSN side, must be carried out by the personnel repairing the electric motor.
9.10. In all cases, portable grounding must be installed on the disconnected ends of the cable by the on-duty personnel of the electrical workshop.
9.11. After the repair is completed, the connection of the supply cable to the motor terminals, as a rule, should be carried out by the personnel repairing the motor. As an exception, in emergency cases, the connection of the cable is allowed to be carried out by the personnel on duty.
9.12. Repair work on electric motors located on the territory of the technological workshop is carried out according to the orders and orders issued by the electrical workshop from a daily permit. decision of the shift supervisor of the technological shop, who must record this in his operational log. The permission must be given by telephone to the on-duty personnel of the electrical workshop (allowing) and recorded in its operational log.
9.13. During the overhaul and current repairs of the unit, access to work on electric motors located in the premises of the technological workshop and located in the area of the general order must be carried out according to the orders and orders endorsed by the responsible manager in accordance with the general order.
Permission for daily admission from the shift supervisor of the technological shop is not required in this case. Access to work is carried out by the on-duty personnel of the electrical workshop. The provision of orders and orders for approval to the responsible manager for the general order should be done by the head of work for the repair of the electric motor.
9.14. Testing of control circuits, protection devices and technological interlocks acting on the electric motor switch is allowed to be carried out on the unit being repaired (with the current general order), provided that the switchgear trolley is installed in the test position and there is grounding in the switchgear cell.
9.15. Testing should be carried out at the request of the personnel of the ETL or the thermal automation shop with the permission of the shift supervisor of the technological shop after confirmation by the shift supervisor of the electrical shop that the above testing conditions are met.
9.16. Testing of technological protections and interlocks should be carried out with a minimum number of operations with switching equipment (to reduce wear, save adjustments of the switch and contact block).
9.17. The assembly of the circuit for testing the electric motor is carried out by the duty personnel of the electrical workshop at the request of the work manager with the permission of the shift supervisor of the technological workshop.
9.18. The electric motor being tested is switched on by the on-duty personnel of the process shop at the direction of the shift supervisor of the process shop and at the command of the work manager conducting the testing.
At the time of testing, a prohibitory poster “Do not turn on! People are working” is removed from the switch control key and re-installed at the end of testing.
10 Maintenance, scope of repairs and testing of electric motors.
10.1. Maintenance and repair provide for the implementation of a set of works aimed at ensuring the good condition of electric motors, their reliable, safe and economical operation, carried out with a certain frequency and sequence at optimal labor and material costs.
10.2. Maintenance, which does not require the withdrawal of electric motors for current repairs, provides for:
Bypasses according to the schedule and technical inspection of working electric motors;
Control of the technical condition of electric motors using external means of control or diagnostics, including control by portable equipment;
Replenishment and replacement of lubrication of rubbing parts, cleaning of oil and water filters, tightening of oil seals, checking of control mechanisms, etc.;
Elimination of water, oil leaks and other individual defects identified in the process of monitoring the condition, checking for performance;
Adjustment and purge of the brush apparatus of synchronous electric motors;
Inspection and testing of electric motors while they are in reserve or on conservation in order to identify and eliminate deviations from the normal state;
Monitoring the health of measuring systems and measuring instruments, including their calibration and other work to maintain the good condition of electric motors;
10.3. At each power plant:
The scope of work for the maintenance of engines and the frequency (schedule) of their implementation for each group of mechanisms are established, taking into account the requirements of the manufacturer and operating conditions;
Responsible executors of maintenance work are appointed or an agreement is concluded with a contracting company for the performance of these works;
A system for monitoring the timely conduct and scope of work performed during maintenance is being introduced;
Maintenance logs (operational logs) are drawn up, in which information about the work performed, deadlines and performers should be entered.
10.4. The frequency and scope of maintenance of electric motors and spare parts for them stored at the power plant is established by power plants in accordance with the instructions for the storage and preservation of motors and spare parts for them.
10.5. The type of repair of electric motors is determined by the type of repair of the main equipment, but may differ from it and be determined by the power plant, based on local conditions.
10.6. Overhaul of electric motors, as a rule, is carried out simultaneously with the repair of the mechanism. Combining the terms of repairs of electric motors with mechanisms is advisable in terms of reducing labor costs for work related to centering, preparing the workplace of the unit, etc.
If, due to its technical condition, the electric motor cannot ensure reliable operation until the next overhaul of the technological unit, then the malfunction must be eliminated during the current repair.
When planning the timing of major and current repairs, it is necessary to take into account the technical condition of electric motors, which is established during operation (heating of active parts, vibration, condition of bearings, etc.).
10.7. Schedules and volumes of repairs are approved by the technical manager of the power plant and are binding on the repair personnel. When repairing electric motors by a contractor, schedules and volumes are additionally agreed with the management of the latter.
10.8. Before putting the electric motor into repair, all preparatory work must be completed:
Long-term and annual plans for preparation for repairs have been developed;
A list of planned work on the repair of electric motors provided for in the annual plan was prepared;
Compiled and approved technical documentation for modernization or reconstruction;
Prepared the necessary materials, tools and fixtures;
Lifting mechanisms and rigging devices are brought into line with the rules of Gosgortekhnadzor;
Necessary spare parts are prepared;
Fire fighting and safety measures have been taken.
10.9. The start of the repair of the electric motor is considered to be the time of withdrawal for repair, set by the shift supervisor of the power plant,
10.10. Before stopping the electric motor for repair during its operation under load, operational measurements of the parameters of the electric motors and an assessment of the current state of the engine and its supporting systems are carried out, which are entered in the list of the main parameters of the technical condition of the electric motor, and the equipment and maintenance sites are cleaned.
10.11. During the current repair, the following work is performed:
Cleaning and blowing with compressed air;
Checking the air gaps between the stator and the rotor;
Measurement of clearances in plain bearings;
Revision of the terminal box and contact connections;
Revision of the bearing unit, replacement or addition with: strokes.
10.12. The scope of overhaul of the electric motor according to the standard nomenclature includes the following works:
10.12.1. DC motors:
Pre-repair measurements and tests , flaw detection in assembly;
Dismantling from the place of installation and transportation to the workshop;
Examination air gaps between armature and poles;
Disassembly electric motor;
Cleaning and blowing with compressed air, as well as with the use of detergents;
Detection wrapped anchor;
Groove and prodorazhivanie collector, checking the quality of the soldering of the armature winding to the collector;
Traverse detection, revision of brush holders, replacement of electric brushes;
Detection of the magnetic system and repair of the coils of the main and additional poles;
Detection of the frame and bearing shields;
Revision and replacement of rolling bearings;
Assembly of the electric motor;
Installation at the installation site, alignment with the mechanism;
Measurements and tests after repair.
10.12.2 Asynchronous and synchronous motors:
Pre-repair measurements and tests, complete fault detection;
Dismantling from the installation site and transportation to the workshop;
Checking the air gaps between the armature and the rotor, in plain bearings;
Complete disassembly with rotor output (on site or in the workshop);
Inspection and cleaning of all parts and assemblies;
Checking the density of pressing of the active steel of the stator;
Inspection of welds and fasteners;
Checking the fastening of the stator winding in the slot and frontal parts;
Inspection of connections, terminals of the stator winding and terminal box;
Checking the fastening of the active steel of the rotor, blades and fan hub;
Inspection of the squirrel cage, fans and shrouds of the rotor;
Checking the serviceability of the rods of squirrel-cage rotors and their density in the groove;
Checking the fastening of poles, pole windings and interpole connections of synchronous motors;
Checking the integrity of the damper (starting) winding;
Detection of slip rings with their groove and grinding, checking the condition of traverses, brush holders, replacing defective and worn electric brushes;
Checking the fastening of balancing weights; replacement of grease and repair of bearings;
Detection and repair of the thrust bearing (disassembly and cleaning of the oil pan, removal of the segments and their supports; checking the condition of fasteners and welds, the sockets of the support bolts of the segment stops; checking the condition of the mirror surface of the disk, the insulating gasket and its tight fit on the thrust bearing bush; checking the segments and their supports, shaping them on the surface plate; installation of segments and adjustment of the load on the segments; replacement of sealing elements, assembly of the oil tank and its sealing);
Audit of the cooling system (dismantling of the air cooler, oil cooler, their disassembly, cleaning and flushing, replacement of gaskets and assembly; hydraulic testing and elimination of detected defects; installation of the oil cooler and its pressure testing with the system; revision, testing with high water pressure of the air cooler and heat exchanger of the water cooling system of the AB electric motor (2AB)-8000/6000, hydraulic testing of the water supply units of the rotor winding and the stator core of these electric motors);
Stator painting;
Assembly of the electric motor;
Electrical measurements and tests after repair.
10.13. After stopping the electric motor for repairs, the personnel of the electrical workshop must:
Perform all shutdowns that ensure safe working conditions;
Issue a work permit for the repair of an electric motor;
Establish the working hours of support workers (warehouses, laboratories, cranes, etc.).
10.14. During the repair process, the management of the electrical department must:
Carry out incoming quality control of used materials and spare parts;
Carry out operational quality control of the repair work performed;
Check compliance with technological discipline (fulfillment of the requirements of technological documentation, the quality of the devices and tools used).
10.15. During the overhaul of the electric motor, its components can be reconstructed in order to eliminate the shortcomings identified during operation, as well as special work related to the repair or replacement of individual components. Changing the dimensions of parts, replacing components with products of a different type must be agreed with the manufacturer of the electric motor.
10.16. Special works related to the repair of the rotor and stator windings, with their partial or complete replacement, with the repair of rotor shrouds and reconstruction, are, as a rule, carried out by a repair company.
10.17. Measurement of the vibration of the electric motor (bearings, stator and foundation plate) should be carried out in the vertical, transverse and axial directions after each scheduled repair, as well as after cleaning or replacing the bearing shells, correcting the alignment, or in case of obvious signs of increased vibration.
10.18. High-voltage electric motors, as well as critical electric motors, regardless of voltage, after installation or overhaul, must be accepted by a commission headed by the management of the electrical shop with the execution of a bilateral act for each electric motor.
Acceptance of the electric motor is carried out partially in accordance with the repair technology - during the assembly process after the repair work has been completed; in general - after assembly in the process of testing under load.
10.19. Information about the repair must be entered in the documentation of the electric motor no later than 10 days after the completion of the repair.
10.20. The suitability of the electric motor for operation is determined on the basis of the results of tests carried out in accordance with the requirements of chapters 4 and 5 of the current "Scope and standards for testing electrical equipment" and on the basis of all tests and inspections carried out.
11 Safety precautions when servicing electric motors. Fire safety.
11.1. The basis for the safe operation of electric motors is the fulfillment of the requirements of the current PTE, PTB, PPB, factory instructions for specific types of machines, compliance with permissible operating modes (in terms of load, heating, vibration, lubrication, etc.) and maintenance (inspections, repairs preventive tests).
11.2. The operational and maintenance of electric motors should be allowed to persons who have been trained, instructed and specially trained to study the principles of operation, device, layout and method of servicing electric motors, who have acquired skills and practical work experience, who have passed exams on knowledge of the rules of technical operation, safety precautions, official and local operating instructions for the equipment assigned to them.
11.3. Repair and restoration work on a specific electric motor should be carried out, as a rule, on a stopped unit with a work permit.
The admission of repair teams to the place of work is carried out by the duty personnel of the power plant.
11.4. The admission of teams to repair work on the rotating and current-carrying parts of the electric motor should be carried out after the implementation of technical measures, which are described in sufficient detail in Section 11.
11.5. Winding outlets and cable funnels for electric motors must be covered with guards, the removal of which requires unscrewing the nuts or unscrewing the bolts. These guards must not be removed while the motor is running.
11.6. Rotating parts of electric motors and parts connecting electric motors with mechanisms (couplings, pulleys) must be protected from accidental touches.
11.7. With a two-speed motor running, the unused stator winding and the cable supplying it must be considered live.
11.8. When working on the mechanism and the electric motor at the same time, the coupling must be disengaged. The disengagement of the clutch must be carried out by the repair personnel along with the repair of the rotating mechanism.
11.9. Before starting work on the electric motor that drives the pump or draft mechanism, measures must be taken to prevent the rotation of the electric motor from the side of the mechanism. Such measures are the closing of the corresponding valves or gates, locking their handwheels with a lock using chains or other devices and devices. Posters “Do not open! People are working” and “Do not turn on! People are working”, prohibiting the supply of voltage and operating shut-off valves, and at the place of work - a safety sign “Work here!”.
11.10. Work on an electric motor (or a group of electric motors)", from which the supply cable is disconnected, and its ends are short-circuited and grounded, can be carried out without a work order, by order.
The supply of operating voltage to the electric motor before the completion of work (trial switching, testing of the electric motor or its starting device) can be done after the removal of the team, the return of the work order to the operational personnel by the manufacturer and the removal of temporary fences, locking devices and posters.
The foreman is obliged to warn the workers of his team about the supply of voltage.
The preparation of the workplace and the admission of the brigade after the trial inclusion is carried out as with the initial admission.
11.11. During the repair period, it is forbidden to use flammable detergents to clean metal parts, assemblies and windings with thermosetting insulation from contamination.
11.12. It is forbidden to service electric motors in a women's dress, in raincoats, coats and gowns because of the possibility of being caught by the rotating parts of these clothes.
11.13. Maintenance of the brush apparatus with the electric motor running is allowed by order of a person trained for this purpose with group III electrical safety, subject to the following precautions:
Work with the use of face and eye protection, in buttoned overalls, being careful not to capture it by the rotating parts of the electric motor;
Use dielectric galoshes, carpets;
Do not touch the current-carrying parts of two poles or the current-carrying and grounding parts at the same time.
The rotor rings may only be ground while the motor is rotating with pads made of insulating material.
11.14. It is forbidden to use rubber, polyethylene and other gaskets made of soft and non-oil resistant material for flange connections of oil pipelines of the electric motor lubrication system.
11.15. It is forbidden to carry out work on the oil pipelines and equipment of the oil system during its operation, with the exception of changing pressure gauges and adding oil.
11.16. Extinguishing fire in electric motors (after de-energizing them) should be carried out with water, carbon dioxide or bromine ethyl fire extinguishers.
It is not allowed to extinguish a fire in electric motors with foam fire extinguishers or sand.
11.17. If a winding fire inside the motor housing is detected, it must be disconnected from the network, and excitation is removed on the synchronous motor.
The fired winding of the electric motor can be manually extinguished by personnel through special inspection and technological hatches using mobile fire extinguishing equipment (fire extinguishers, fire nozzles, etc.) after the electric motor is turned off.
12 General guidelines for the preparation of local regulations.
12.1. Based on this Model Instruction, a local instruction must be drawn up at each power plant. At the same time, the requirements and recommendations of manufacturers, industry norms, taking into account operating experience and test results, as well as the specific conditions in which electric motors are operated, must be fully taken into account.
12.2. The local instructions should include those sections and paragraphs of this Standard Instruction that relate to all the main issues of operation of electric motors installed at this power plant, in relation to local conditions.
12.3. The local operating instructions for electric motors must specify:
Permissible conditions and modes of operation of electric motors;
Brief description of the main most powerful electric motors of different voltage classes, their supporting systems (cooling, excitation, lubrication, thermal and technological control and protection devices);
Distribution of responsibilities for the maintenance of electric motors between the shops of the power plant;
The procedure for preparing for launch, the procedure for starting, shutting down and maintenance during normal operation and in emergency modes;
The procedure for admission to inspection, repair and testing of electric motors;
Safety and fire safety requirements specific to a particular group of electric motors,
12.4. The job description of each person who is entrusted with the implementation of the requirements of the local instructions for the operation of electric motors should include the relevant sections and paragraphs to be performed by these persons (electrician on duty, driver on duty, lineman on duty, foremen).
12.5. In the relevant paragraphs of the local instructions, all instructions on the modes, frequency of inspections and control over the operation of electric motors must be given specifically for each type of electric motors in operation. In addition, the frequency of measuring the vibration of bearings of critical mechanisms should be established.
12.6. In the event of a change in the state or operating conditions of electric motors, appropriate additions must be made to the local instructions, bringing them to the attention of employees, for whom knowledge of this instruction is mandatory, with an entry in the order log.
12.7. The instruction must be reviewed at least once every 3 years.
12.8. The local instructions for the operation of electric motors must be signed by the head of the electrical department and approved by the technical manager of the power plant.
12.9. In the local operating instructions for electric motors, the list of emergency situations should be specified in accordance with local conditions.
12.10. The local instructions should contain a list of critical mechanisms approved by the technical manager of the power plant, the re-activation of which after being turned off by the protections is allowed after an external examination.
12.11. The local operating instructions for electric motors should contain a list of protections, interlocks and alarms.
Application
Typical malfunctions of electric motors and their elimination
p.p. |
signs abnormal phenomenon |
Likely Causes |
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At start electric motorbuzzes and does not turn around |
Breakage of one phase in the stator circuit (fuse blown, poor contact in the switch, etc.). Breakage or poor contact in the rotor circuit (kink or burnout of the rods in the area of short-circuit rings). |
Using a megohmmeter, identify a circuit violation and eliminate it. |
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Detect cracks or breaks in the rods by measuring the magnetic leakage flux Along the circumference of the rotor using the VAF-85 (see the methodology in EC No. E-11/61 or § 6.60 SDME-81) or in another way. |
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The stator winding circuit is assembled incorrectly (“star” instead of “triangle”, one phase is turned out, etc.). Mechanical jamming in the drive mechanism or motor |
Check the polarity of the leads (determine the beginnings and ends of each phase) and assemble the stator winding circuit according to the manufacturer's instructions. Bring the unit in for repair and eliminate jamming |
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Engine emits sparks and smoke when starting or during operation |
The grazing of the rotor on the stator due to the ingress of a foreign object into the air gap, excessive wear of the bearings. |
Bring the unit in for repair to eliminate the defect. |
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There was a break in the rod of the short-circuited rotor winding. |
Take the engine out for repair. |
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Interturn short circuit in the stator winding |
Troubleshoot winding |
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Overcurrent protection works at start |
Short circuit in the stator circuit (in the cable, in the stator winding, terminal box). |
Inspect the entire circuit up to the switching device, measure the insulation resistance of the circuit elements. If a short circuit is found, remove the connection for repair. Change the protection settings according to the motor start detuning conditions. Bring the drive mechanism in for repair |
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The protection operation current is low or the overcurrent time delay from overload is short. Drive mechanism defective |
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Increased bearing vibration |
The alignment of the engine with the drive mechanism is broken. |
Align the motor with the drive mechanism. |
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Rotor imbalance, clutch imbalance. |
Balance the rotor. Remove the clutch and balance separately from the rotor. Carry out the foundation in accordance with the factory installation requirements. |
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Insufficient rigidity of the foundation. |
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There are gaps between the engine feet and the foundation |
Eliminate gaps with gaskets. |
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The motor feet on the drive side are not pinned and the belleville springs are not installed on the foundation bolts on the side opposite to the drive. |
Install pins and cup springs. |
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The coupling is defective, there are defects in the gear coupling due to incorrect engagement, inappropriate tooth processing. There is a misalignment between the half-couplings mounted on the shafts, one or both half-couplings are beaten, the fingers of the elastic-finger coupling are installed incorrectly or are worn out. |
Repair or replace gear coupling. Check the correctness of the nozzle and the runout of both halves of the couplings, check the installation of the fingers in the halves of the couplings. If necessary, eliminate the increased runout of the coupling halves, correct the installation of the fingers or replace them with new ones. |
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Temperature of oil entering forced lubricated bearings too low |
During engine operation, incoming oil should have a temperature of 25-45°C |
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When the engine is running, rhythmic oscillations of the stator are observed |
Contact failure or coil short circuit in the rotor winding |
Carry out inspection and necessary repair of the rotor |
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Water leak from the air cooler, the sensor for monitoring the presence of water in the engine is triggered |
Possible cracks in the cooling tube at the flare or weakening of the flare |
Remove water from engine. Carry out a hydraulic test of the air cooler to determine the location of the leak. It is allowed to plug one defective tube on both sides with plugs. If more tubes are damaged, replace the air cooler |
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Leakage of water in the electric motor АВ(2АВ)-8000/6000 in the weld or in the connection of the "nipple rod" of the rotor |
Fistula or fissure formation |
Cut out the leak to a depth of 4 mm. Solder with PSR45 solder with PV209X flux. After filling the blank with solder, maintain for 1 min. heating of the neck of the rod to reduce stresses in the “fitting-rod” connection. |
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in the “rod-short-circuiting ring” connection of the rotor |
Same |
Cut and remove the technological steel sleeve, cut a groove 5 mm deep around the rod. Solder with PSr45 solder with PV209X flux, maintaining heating of the rod neck during cooling. |
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through tubes inside the stator core segment |
Cracks, fistulas |
Exclude a segment from the circuit with a jumper. It is allowed to exclude up to two parallel branches, the distance between which must be at least three packets. In the two extreme branches from each end of the core, segments are not allowed to be excluded. |
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in collector stator |
Loose fittings. |
Tighten nuts, tighten. |
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Loosening of the rubber seals in the end caps. |
Tighten flanges or replace rubber seals |
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Damage to the welds on the manifold. |
Weld welds |
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Contamination of mating sealing surfaces |
Thoroughly clean sealing surfaces |
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Increased leakage of cooling water through the rotor АВ (2АВ)-8000/6000 |
PTFE seal wear |
Replace bushing |
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Overheating of the entire stator winding and active steel. Elevated temperature of the cooling air at the outlet of the cooler |
Increasing the load more than acceptable. |
Reduce the load to nominal and below. |
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Cooling water temperature increase above normal |
Increase the water flow above normal, but no more than twice (at the same time, the pressure in the cooler should not exceed the maximum allowable). |
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Reducing water consumption |
Clean the cooler by removing both covers from it. Rinse the tubes with a 5% hydrochloric acid solution and clean with special brushes (“ruffs”). |
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Clogging of the annulus of the cooler |
Check the filters, thoroughly blow the annular space with compressed air |
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Increasing the water temperature at the outlet of the rotor, stator АВ (2АВ)-8000/6000 |
Blockage in the cooling path of the rotor or stator |
Carry out reverse washing with water at a temperature of 80-90°C. With a small effect of this method, use chemical reagents (5% hydrochloric acid solution and 5% chromic anhydride solution) |
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There is no indication of one of the resistance thermocouples |
Breakage of the sensor or measuring wiring |
Replace the defective converter, eliminate the break or put into operation the spare cable core |
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Excessive heating of bearings |
Insufficient oil supply to the bearings (seized oil ring). Excess or lack of lubrication in rolling bearings. |
Increase oil supply to bearings, repair ring failure. Check the quantity and quality of lubricant. If necessary, flush and fill the bearing with the correct amount of grease. |
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Lubricant or oil contaminated |
Clean the oil chambers of the bearings, change the oil. |
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Wrong brand of oil used. |
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Axial impact on the motor rotor from the driven mechanism. |
Check the alignment and connection of the motor with the driven machine |
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No run-up of the rotor |
Check the presence of shims between the bearing housing and the shield on the side of the working end of the shaft. |
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Increased rotor vibration |
See paragraph of this table |
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Oil leakage from bearings |
Increased oil consumption through bearings. |
Adjust oil flow. |
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Clogged drain oil pipeline Insufficient sealing of the joints between the labyrinth seals and the bearing housing |
Clean the oil drain line. Replace gaskets between labyrinth seals and bearing housing |
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Reduced stator winding insulation resistance |
Dirty or damp winding |
Dismantle the motor, blow dry with compressed air, wipe the winding with a cloth moistened with detergent, dry the insulation |
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Increased brush spark |
Insufficient pressing force of the brushes to the slip rings. |
Adjust brush pressure. |
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Intersectoral rules for labor protection (safety rules) for the operation of electrical installations M .: Publishing house NTs ENAS, 2003. . Rectangular plates for machines and devices. Dimensions. |
INSTRUCTIONS
ON INSTALLATION AND OPERATION OF THREE-PHASE ASYNCHRONOUS ELECTRIC MOTORS
1. SAFETY REQUIREMENTS.
Persons who have undergone technical instruction are allowed to install and service engines.
It is forbidden to operate motors without reliable grounding and fastening. For grounding, use only the special ground clamps provided on the motors.
Mounting, maintenance and dismantling of live motors is prohibited. It is forbidden to operate motors with the fan cover and terminal box cover removed.
2. PREPARATION FOR INSTALLATION.
Check that the voltage and frequency of the mains supply correspond to the data given on the rating plate of the motor.
Remove grease from preserved engine parts. Make sure the rotor turns freely by hand. Measure the insulation resistance of the stator and rotor windings (only for motors with a phase rotor) relative to the housing. If the resistance is below 0.5 MΩ, dry the motor. Dynamically balance with half key the drive parts mounted on the end of the shaft.
3. INSTALLATION.
When installing the engine, provide free inflow and outlet of cooling air.
To avoid damage to the bearings, when fitting the drive parts onto the shaft, it is necessary to provide a stop for the shaft on the opposite side. Secure the engine to a solid foundation or suitable foundation.
When connecting the motor to the drive mechanism, it is necessary to ensure the alignment and parallelism of the shaft connection. Permissible shaft misalignment is not more than 0.2 mm.
For a belt drive, it is necessary to ensure the correct mutual arrangement motor and drive shafts. The minimum diameter of the pulley on the shaft and the maximum allowable tension of the belts must be determined in accordance with current regulations. Load the second end of the shaft only by means of an elastic coupling.
4. PREPARATION FOR WORK.
Upon completion of the installation, it is necessary to check the correct connection of the motor to the network according to the diagram on the cover of the terminal box and the passport (nameplate).
Check the tightness of the contact connections in the terminal box, fastening connections and seals in the fittings, the serviceability of the grounding.
To check the correct installation, operation and direction of rotation of the drive, perform a test run of the engine at idle. To change the direction of rotation of the motor, it is necessary to swap any two wires of the supply cable.
After starting at idle and eliminating the observed shortcomings, start the engine under load.
5. IN THE PROCESS OF OPERATION IT IS NECESSARY:
To conduct a general observation of the operation of the engine in order to control the normal technical condition,
Systematically perform maintenance (frequency - at least once every two months),
Carry out current repairs in case of noticed deviations in the amount of bed heating, noise and vibration levels and other deviations in the operation of the engine, but at least once a year.
6. MAINTENANCE.
When servicing the engine, it is necessary to carry out an external inspection, clean the engine from contamination, check the reliability of grounding and the condition of the contacts in the terminal box, and measure the insulation resistance.
Check the mechanical fastening of the motor to the installation site and the connection to the drive mechanism.
7. DURING CURRENT REPAIRS IT IS NECESSARY:
Dismantle and disassemble the engine, wash, clean and dry parts. Inspect bearings, stator and rotor to detect mechanical damage, identify parts that need to be replaced, rebuilt and adjusted.
Feed the felt seals along the shaft line with transformer oil after 3000 hours of operation, but at least once a year.
For engines with open bearings, replenish or completely change the lubricant after 6000 - 10000 hours of operation, but at least once every two years. For replenishment use only mineral oil based greases with lithium thickener.
Bearings should be replaced when the operating time is more than 20,000 hours and with increased bearing knock, noise during engine operation, grazing of the rotor on the stator, and the presence of mechanical damage. Bearings can only be removed from the shaft using a puller.
8. STORAGE.
Motors can be stored in containers or without them in closed ventilated rooms, the atmosphere of which does not contain acid, alkali and other vapors that are harmful to insulation and coatings.
Sharp fluctuations in temperature and air humidity, causing the formation of condensate (dew) are unacceptable.