How to maintain an AC motor？

"AC motor" is a machine used to realize the mutual conversion of mechanical energy and AC electrical energy. Due to the tremendous development of AC power systems, AC motors have become the most commonly used motors. So how is the AC motor usually maintained? Let's take a look next.

Here is the content list:

Common faults of AC motors

Preparation and inspection before start-up

Maintenance in the line

Common faults of AC motors

AC motors are inevitably malfunctioning due to friction, vibration, insulation aging, and other reasons during operation. If these AC motor faults are inspected, discovered, and eliminated in time, accidents can be effectively prevented.

Preparation and inspection before start-up

Firstly, check whether the grounding of the electric and starting equipment of the AC motor is reliable and complete and whether the wiring of the AC motor is correct and good. Second, check whether the voltage and frequency indicated on the nameplate of the AC motor are consistent with the power supply voltage and frequency. Before starting a newly installed or long-term out-of-service AC motor, check the phase-to-phase and phase-to-ground insulation resistance of the winding. The insulating ground group should be greater than 0.5 megohms. If it is lower than this value, the windings must be dried. For the rotor of the wound AC motor, check whether the brush device on the collector ring can work normally and whether the brush pressure of the AC motor meets the requirements. Check whether the AC motor rotates flexibly and whether the oil in the sliding bearing of the AC motor reaches the specified oil level. Check whether the rated current of the fuse used in the AC motor meets the requirements. Check whether the fastening bolts and mounting bolts of the AC motor are tightened. After all the above inspections meet the requirements, the AC motor can be started. After the AC motor is started, run it without load for about 30 minutes. Pay attention to observe whether the AC motor has abnormal phenomena. If abnormal conditions such as noise, vibration, and heat are found, measures should be taken. After the situation is eliminated, the AC motor can be put into operation.

When starting the wound AC motor, the starting varistor should be connected to the rotor circuit. For the electric motor of the AC motor lifting mechanism with an electric brush, the electric brush should be put down, the short-circuiting device should be disconnected, the stator circuit switch should be closed, and the varistor should be moved. When the motor is close to the rated speed, lift the brush, close the short-circuiting device, and the AC motor is started.

Maintenance in the line

The AC motor should always be kept clean, and no debris is allowed to enter the AC motor. The air inlet and outlet of the AC motor must be kept unobstructed. Use meters to monitor AC motor power supply voltage, frequency, and motor load current. The AC motor power supply voltage and frequency must conform to the motor nameplate data, and the motor load current of the AC motor must not exceed the specified value on the nameplate, otherwise, the cause must be found out, measures must be taken, and the undesirable situation can be eliminated before it can continue to run. Take necessary measures to detect the temperature rise of various parts of the AC motor. For phase-wound rotor motors, always pay attention to the contact pressure, wear, and sparks between the brushes of the AC motor and the slip ring. When the AC motor stops, the switch of the AC motor in the stator circuit should be disconnected, and then the brush lifting mechanism of the AC motor should be pulled to the starting position to disconnect the short-circuiting device. Regular maintenance of AC motors after the operation is generally divided into two types: minor repairs and overhauls. Minor repairs are general overhauls. No major disassembly of the AC motor starting equipment and the whole is done. About once a quarter, the major repairs must disassemble all the transmission devices and all parts of the AC motor, and conduct a comprehensive inspection of the disassembled parts. Cleaning is usually once a year.

Every manufacturer has the responsibility to produce AC motors that meet the standards to ensure the healthy development of the AC motor market. Guangzhou Yuexun Electric Appliance Co., Ltd. has conducted a lot of connection tests on AC motors before leaving the factory and provides maintenance and repair of AC motors. If you are engaged in the AC motor business, you can consider using our cost-effective products.