How to judge whether a three-phase motor is good or bad when it is powered on but does not rotate or respond?

The three-phase motor does not rotate or respond when powered on

If the three-phase motor does not rotate or respond after being powered on, it may be caused by the following reasons:

Power failure: First, check whether the power supply is normal. The power switch may be broken, the line may be short-circuited, or the circuit may be open, causing the power supply to fail. At this time, you need to eliminate the power failure and ensure that the power supply is normal.

Motor wiring fault: If the motor wiring is improper, the motor may not start normally. You can check whether the motor wiring is correct and whether the motor terminals are loose or in poor contact.

Motor failure: If the motor is frequently used or aged, it may cause damage or wear of the internal parts of the motor, and thus fail to operate normally. At this time, you need to check whether the rotor, stator, bearings and other parts inside the motor are damaged or need to be replaced.

Overload protection trigger: When the motor is overloaded or overcurrent occurs, the overload protection device may be automatically activated, causing the motor to not operate normally. At this time, you need to check whether the motor load is too heavy or short-circuited, and eliminate the fault in time.

Other factors: There may be insufficient torque when the motor starts, the rotor inside the motor may not rotate flexibly, or there may be a short circuit in the stator winding.

In summary, the motor not turning after being powered on may be caused by power failure, motor wiring failure, motor failure, overload protection triggering or other factors. It needs to be checked and repaired according to the actual situation. It is recommended to ask a professional electrical engineer or motor technician to check and repair.

How to judge whether the motor is good or bad when it is not powered

If the motor is not powered, you can follow the steps below to diagnose and troubleshoot:

Check the power supply: First, check whether the power supply is normal. You can use a multimeter or voltmeter to measure the voltage and current of the power supply to confirm whether the power supply is stable and meets the rated voltage and current of the motor. If the power supply is normal, the possibility of power failure can be ruled out.

Check the fuse and circuit breaker: If the motor is not powered, check whether the fuse and circuit breaker are tripped or disconnected. If a fault is found, replace the fuse or reclose the circuit breaker in time.

Check the wiring: Check whether the motor wiring is correct, loose or poorly connected. You can use a multimeter to check whether the motor terminals are conducting.

Check the motor windings: Use a multimeter or insulation resistance tester to check whether the insulation resistance of the motor windings is normal. If the insulation resistance of the motor windings is too low or there is a short circuit, the motor windings need to be repaired or replaced.

Check the motor's rotor and stator: Check if the motor's rotor and stator are damaged or stuck. If problems are found, the rotor and stator need to be repaired or replaced.

In summary, if the motor does not power on, you need to troubleshoot the problem step by step, including checking the power supply, fuse, wiring, motor windings, rotor and stator, etc., to find out the cause of the problem and repair or replace it. It is recommended to ask a professional electrical engineer or motor technician to inspect and repair it.