YE3 series three-phase asynchronous motors are widely used in various types of mechanical equipment and are the most widely used AC motors. So how to use YE3 series ? How to install YE3 series motors? start up? What should I pay attention to when running and shutting down?
Installation of the electric motor
1 Preparations before installation
Before unpacking the motor, check whether the package is intact and whether there is moisture. After opening the cover, carefully remove the dust and anti-rust layer on the motor, and carefully check whether there is deformation and damage during transportation, and whether the fasteners are loose. Or fall off, whether the rotor rotates flexibly, whether the nameplate data meets the requirements, and use a 500VMQ meter to measure the high-voltage resistance, the insulation resistance should not be lower than 1MQ, otherwise the winding should be dried, but the processing temperature should not exceed J20℃.
2 The installation site and installation foundation of the motor
The altitude of the installation site of the motor should not exceed 1000m; the installation site of the motor for general purposes should be dry and clean, the surrounding of the motor should be well ventilated, and there should be a certain interval with other equipment to facilitate inspection, monitoring and cleaning. The temperature is below 40℃, and strong radiation should be prevented; the installation foundation should be firm and firm, with a certain rigidity, and the installation surface should be flat to ensure the balanced operation of the motor.
3 Wiring of the motor
- The motor should be properly grounded. There are grounding devices in the bottom right of the junction box and the housing of the machine base. If necessary, the motor feet or flanges can be used to fasten bolts to ground to ensure the safe operation of the motor.
- Connection of motor and mechanical load
- The motor can use a coupling, the spur gear shaft or the belt is mechanically connected to the load, and the fan end of the double-shaft extension motor is only allowed to use the coupling to drive.
- When the coupling is used for connection, the center line of the motor shaft and the shaft center line of the load machine should be coincident, so as to avoid strong vibration, coupling movement and abnormal sound of the motor during operation. The installation deviation of the device is: the allowable deviation of the 2-pole motor is 0.015mm, and the deviation of the 4-, 6-, and 8-pole motors is 0.04mm.
- For a three-phase asynchronous motor installed vertically, the shaft extension is only allowed to use a coupling to connect with the mechanical load.
Starting of the motor
1,Inspection before starting the motor
- The insulation resistance should be checked before starting the newly installed or deactivated motor for more than three months, and the measured insulation resistance value is not less than 1MQ.
- Check whether the fastening screws of the motor are tightened, whether the bearings are short of oil, whether the wiring of the motor meets the requirements, and whether the casing is reliably grounded or connected to zero.
- Check whether the screws and pins of the coupling are fastened, whether the belt connection is good, whether the tightness is appropriate, whether the unit rotates flexibly, whether there is jamming, movement and abnormal sound, etc.
- Check whether the rated current of the fuse meets the requirements and whether the installation is firm and reliable.
- Check whether the wiring of the starting equipment is correct, whether the starting device is flexible, whether the contacts are in good contact, and whether the metal shell of the starting equipment is reliably grounded or connected to zero.
- Check whether the three-phase power supply voltage is normal, whether the voltage is too high or too low or the three-phase voltage is asymmetrical.
- Any problems mentioned above must be completely solved, and the machine can be started only after confirming that the preparations are correct.
2.Precautions when starting the motor
- The motor is allowed to start at full voltage or start at reduced voltage (with reactance or Y-△), but it should be noted that it is about 5-7 times the rated current when starting at full voltage, and the torque is proportional to the square of the voltage when starting at reduced voltage , when the power grid capacity is insufficient, it is advisable to use the step-down starting, and when the static load is quite large, the full-voltage starting can be used.
- When the phase sequence A, B and C of the power supply are connected to the terminals Ul, V1 and w of the terminal board respectively. Correspondingly, the rotation of the motor is regarded as clockwise from the main shaft end.
- The motor should generally have thermal protection device, and the setting value of the protection device should be adjusted according to the rated current of the motor.
- After closing, if the motor does not turn, it should be pulled quickly and decisively to avoid burning the motor.
- After the motor is started, pay attention to observe the transmission device, the production machinery and the voltage and current of the line. If there is any abnormal phenomenon, it should be stopped immediately to find out the fault and remove it before re-closing and starting.
- According to the technical requirements of the motor, the number of consecutive starts of the motor is limited, generally no more than 3 consecutive starts at no load, and the motor runs to a hot state for a long time, and then starts after stopping, not more than 2 times.
- When several motors are powered by the same transformer, they cannot be started at the same time, and should be started one by one from large to small.
Operation of 3 phase induction motor
- During the operation of the motor, the surface should be kept clean, and the air inlet should not be obstructed by dust fibers.
- The deviation between the power frequency and the rated frequency shall not exceed 1%; the deviation between the power supply voltage and the rated voltage shall not exceed 5%.
- The current of the motor is not allowed to exceed 10% of the rated current.
- Long-term overload operation is not allowed for motors that work continuously.
- There should be no intermittent or abnormal sound or vibration when the motor is running without load or under load.
- When the thermal protection device and short-circuit protection device of the motor operate continuously, the cause of the fault should be checked (whether it is from the motor or from overload or because the setting value of the protection device is too low), and it can be put into operation after the fault is eliminated.
- During operation, use a thermometer to measure the temperature rise of the casing, generally not exceeding 75℃.
- The motor bearing should be well lubricated during the operation. Generally, the motor should run for about 2000H, that is, the lubricating finger should be supplemented or replaced (the enclosed bearing does not need to replace the grease during its service life). If it is found that the bearing is overheated (generally the bearing temperature rise should not exceed 95 ℃) or the grease is deteriorated, the grease should be replaced in time. When replacing, the old grease should be removed first, and then the grease of the bearing and bearing cover should be washed with gasoline, and then the grease should be cleaned. ZI-3 lithium-based grease fills 1/2 (2 poles) or 2/3 (4, 6, 8 poles) of the cavity between the inner and outer rings of the bearing.
- When the bearing clearance reaches the following limit wear clearance value, the bearing should be replaced in time.
- Shutdown processing
When the following conditions are found during the operation of the motor, it should be stopped immediately
(1) A personal electric shock accident occurs.
(2) There is smoke and fire on the motor or starting device.
(3) The motor vibrates violently.
(4) The bearing heats up violently.
(5) The motor has channeling, sweeping, a sudden drop in speed, and a rapid rise in temperature.
Storage and transportation of electric motors
- The storage of the motor should be kept dry to avoid sudden changes in the ambient temperature.
- The motor should be prevented from tilting during storage and transportation.
- The storage of the motor should not be too high, so as not to affect the ventilation and damage the packaging of the lower motor.