1. The cause of the problem
1) Excessive power supply voltage greatly increases the core heating;
2) The power supply voltage is too low, the motor operates with rated load, and the current overflow the ambassador winding and generates heat;
3) Improper thermal dismantling method is used to repair and dismantle the windings, and the iron core is burned;
4) Constant rotor core rubbing;
5) Overload or frequent starting of the motor;
6) Broken bars of cage rotor;
7) The motor is out of phase and operates in two phases;
8) After rewinding, the dipping paint for the winding is not sufficient;
9) There is much dirt on the surface of the motor with high ambient temperature, or the ventilation duct is blocked;
10) Motor fan failure, poor ventilation; Stator winding fault (interphase and inter-turn short circuit; The internal connection of stator winding is wrong.
2. troubleshooting
1) reduce the supply voltage (e.g., adjust the power supply transformer tap), if the motor Y, Δ connection errors, you should correct connection;
2) Increase the power supply voltage or change the coarse power supply conductor;
3) Inspect the iron core and troubleshoot it;
4) Eliminate friction points (adjust air gap or file and rotor);
5) lightening; Controlled starting according to the specified number of times;
6) Check and eliminate rotor winding faults;
7) Resume three-phase operation;
8) Secondary and vacuum impregnation processes are adopted;
9) Clean the motor, improve the ambient temperature, and adopt cooling measures;
10) Check and repair the fan and replace it if necessary; Repair stator winding and eliminate the fault.
