What is the reason for the high no-load current of the motor and the heat?

There are many users who have this problem  . The motor becomes hot when it is unloaded. The measured current is stable, but the current is large. Why is this and how to deal with this kind of failure? 

1. Cause of failure

① When the motor is repaired, the number of turns of the stator winding is reduced too much ;

②The power supply voltage is too high;

③Y is wrongly connected to the motor and it is △;

④In the motor assembly, the rotor is installed upside down, so that the stator core is not aligned and the effective length is shortened;

⑤ The air gap is too large or uneven;

⑥ When the old winding is removed for overhaul, the hot dismantling method is used improperly, which causes the iron core to burn out.

2. Troubleshooting

① Rewind the stator winding to restore the correct number of turns;

② Try to restore the rated voltage;

③Change to correct connection

④ reassembly;

⑤Replace with a new rotor or adjust the air gap;

⑥Repair the iron core or recalculate the winding, and increase the number of turns appropriately.