Three-phase AC servo motors are widely used, but after long-term operation, various failures will occur. Timely judgment of the cause of the failure and corresponding treatment is an important task to prevent the expansion of the failure and ensure the normal operation of the equipment.

After the 1. is energized, the motor cannot rotate, but there is no abnormal noise, odor and smoke.

1. Cause of failure ① Power supply is not connected (at least two phases are not connected);② Fuse is blown (at least two phases are blown);③ Overcurrent relay is too small; ④ Control equipment wiring error.

2. Troubleshooting ① Check whether there are breakpoints at the power circuit switch, fuse and junction box, and repair them; ② Check the fuse type and fuse cause, and replace the fuse; ③ Adjust the relay setting value to match with the motor; ④ Correct the wiring.

After the 2. is energized, the motor does not turn and there is a buzzing sound.

1. Cause of failure ① Rotor winding is open circuit (one phase is broken) or one phase of power supply is lost; ② Wrong connection at the beginning and end of winding lead wire or reverse connection inside winding; ③ Loose contact of power supply circuit and large contact resistance; ④ Excessive motor load or rotor stuck; ⑤ Too low power supply voltage; ⑥ Too tight assembly of small motor or excessive grease in bearing; ⑦ The bearing is stuck.

2. Troubleshooting ① Find out the breakpoint and repair it; ② Check the winding polarity; Judge whether the winding end is correct; ③ Tighten the loose wiring screws, use a multimeter to judge whether each joint is falsely connected, and repair it; ④ Load reduction or detection and elimination of mechanical faults, ⑤ Check whether the specified surface connection is misconnected; Correct if the voltage drop is too large due to too thin power supply wires, ⑥ Reassemble to make it flexible; Replace qualified oil

Grease; ⑦ Repair the bearing.

The 3. motor is difficult to start, and the motor speed is much lower than the rated speed at rated load.

1. Causes of failure ① The power supply voltage is too low; ② The motor is misconnected by surface connection method; ③ The rotor is welded or broken; ④ The local coil of the rotor is misconnected and reversely connected; ③ The number of turns is increased too much when the motor winding is repaired; ⑤ The motor is overloaded.

2. Troubleshooting ① Measure the power supply voltage and try to improve it; ② Correct the connection method; ③ Check the welding opening and breakpoint and repair it; ④ Find out the wrong connection and correct it; ⑤ Restore the correct number of turns; ⑥ Load shedding.

4. motor no-load current imbalance, three-phase difference is large

1. Causes of failure ① Wrong connection of winding end and end; ② Unbalanced power supply voltage; ③ Winding has inter-turn short circuit, coil reverse connection and other faults.

2. Troubleshooting ① Check and correct; ② Measure the power supply voltage and try to eliminate imbalance; ③ Eliminate winding faults.

Abnormal noise and abnormal noise during operation of 5. motor

Cause of failure ① bearing wear or sand and other foreign matter in the oil; ② rotor core loose; ③ bearing lack of oil; ④ power supply voltage is too high or unbalanced.

Troubleshooting ① Replace the bearing or clean the bearing; ② Repair the rotor core; ③ Add oil; ④ Check and adjust the power supply voltage.