Simo Electric Motor Repair Plant Technical Note:

After the motor repair, it must undergo testing and inspection to verify its compliance. The repaired motor should pass all electrical tests, with the data falling within the normal range, and the insulation should meet the required standards. All instruments and indicator lights must be functioning properly.

Simo Electric Motor Repair Technical Check:

1. The motor wiring should be correct and securely connected, with the cable shielding properly installed.

2. After the repair, the rotor should rotate manually with ease, without any sticking or jamming. The bearings should not show signs of lack of lubrication or oil leakage.

3. The ground connection of the motor should be secure. The motor body should be clean and free of debris, and the surrounding area should be tidy.

4. After the motor repair, conduct a no-load test for 2 hours to measure the no-load current. The motor’s vibration, bearing temperature, and casing temperature should all be within acceptable ranges, and the bearing noise should be normal.

Use a multimeter set to RX10K or higher (the higher, the better) to measure the resistance between any terminal in the junction box and ground. The resistance should ideally show infinity, indicating no short circuit or leakage to ground. Remove the copper pieces connecting the terminals, and set the multimeter to RX1Ω. Measure the resistance between pairs 1-4, 2-5, and 3-6. Compare the results: if the resistance of any pair is too low, it indicates an inter-turn short circuit. If the resistance is too high, it indicates an open circuit in the winding. If the resistance shows infinity, this indicates a short circuit.

If all of the above checks are normal, reconnect the terminals. Set the multimeter to the 50µA setting. Rotate the motor rotor while alternately connecting the multimeter leads to any two phases. The needle should move back and forth, with equal amplitude in all three phases. This indicates the motor is in good condition.

For single-phase motors, the procedure is similar. Start by measuring the resistance of the main winding to check for continuity. If there's no continuity, a broken wire is likely. Then, measure the resistance of the two sets of main winding coils; if the resistance values differ, the winding with the lower resistance likely has a short circuit. Next, check the resistance of the starting winding, which should be higher than the main winding. Use the same method to check the insulation resistance between the main and auxiliary coils, as well as between the coils and the motor casing. The resistance should show infinity, and using a megohmmeter, it should be greater than 0.5MΩ to be considered acceptable.