1. Preparation and inspection before starting
1. Check whether the grounding of electric and starting equipment is reliable and complete, and the wiring is correct and good.
2. Check whether the voltage and frequency shown on the motor nameplate are consistent with the power supply voltage and frequency.
3. The newly installed or long-term shutdown motor should check the relative phase and relative ground insulation resistance of the winding before starting. The group of insulated ground should be greater than 0.5 megohm. If it is lower than this value, the winding must be dried.
4. For the wound rotor, check whether the brush device on the collector ring can work normally and whether the brush pressure meets the requirements.
5. Check whether the motor rotates flexibly and the oil in the sliding bearing reaches the specified oil level.
6. Check whether the rated current of the fuse used in the motor meets the requirements.
7. Check whether the tightening bolts and mounting bolts of the motor are tightened.
After all the above inspections meet the requirements, the motor can be started. After the motor is started, run it with no load for about 30 minutes. Observe whether the motor has any abnormal phenomena. If abnormal conditions such as noise, vibration and heat are found, measures should be taken.
When starting the winding motor, the starting rheostat should be connected to the rotor circuit. For the motor with brush lifting mechanism, the brush should be put down, the short circuit device should be disconnected, the stator circuit switch should be closed, and the rheostat should be pulled. When the motor is close to the rated speed, lift the brush and close the short-circuit device, the motor starts to complete.
2. On-line maintenance
1. The motor should always be kept clean, and no debris is allowed to enter the motor; the air inlet and air outlet must be kept clear.
2. Use the meter to monitor the power supply voltage, frequency and load current of the motor. The power supply voltage and frequency must comply with the motor nameplate data, and the motor load current must not exceed the specified value on the nameplate. Otherwise, it is necessary to find out the cause and take measures to continue operation after the bad situation is eliminated.
3. Take necessary measures to detect the temperature rise of each part of the motor.
4. For phase-wound rotor motors, always pay attention to the contact pressure, wear and sparks between the brush and the slip ring. When the motor stops, the switch in the stator circuit should be disconnected, and then the brush lifting mechanism should be pulled to the starting position to disconnect the short-circuit device.
5. Regular maintenance after motor operation, generally divided into minor repair and overhaul. Minor repairs are general overhauls and do not require major disassembly of the motor starting equipment and the whole. Once every quarter, major repairs should dismantle all transmission and motor parts, and carry out comprehensive inspection and cleaning of the disassembled parts Usually once a year.
