Key Points

It is common for the outer shell to be charged. When touching the outside, use the back of your hand;
Discharge due to poor grounding. The causes of electric shock can be both internal and external.
Check the grounding wire for connection. Internal leakage is caused by damaged insulation.
The charged part touches the shell and is exposed outside. Open the motor and take a careful look.

Touch the outer shell of the Simo asynchronous motor with the back of your hand. If you feel a tingling sensation of electric shock, it indicates that the outer shell of the motor is charged. The inspection methods are as follows:

(1) When the motor is in operation, its outer shell must be grounded. After inspection, the grounding wire of the motor is in good condition, but the grounding wire and the grounding bolt of the motor are rusted, so that the charge on the outer shell of the motor cannot be properly conducted into the ground.

(2) Poor grounding of the motor is a common cause of electric shock to people. If the insulation between the outer shell of the motor and the internal live parts is good, the outer shell should not be charged. The outlet box of the motor should be inspected. It is found that in the junction box, the exposed length of the lead wire of one-phase winding is relatively long and is very close to the inner wall of the junction box. When the motor is running, due to vibration, this wire sometimes comes into contact with the outer shell.