The causes of three-phase AC motor burnout can be divided into load, power supply, motor insulation, and phase loss.
Three-phase AC motor load (overload) burnout: Under overload operation, the motor heats up. Or the motor starts frequently and the motor overheats. When both ends of the stator are burned inside the motor and the burned parts become uniform (generally speaking, the motor has a constant operating power, called rated power, in watts (w), and in some cases the actual power used by the motor exceeds the rated power of the motor, this phenomenon is called motor overload. Causes of three-phase AC motor power lighter: The voltage is too low, the load is rated, the current becomes larger, and the motor overheats. The power supply voltage is too high, and the barbecue machine is burning. Or the motor is running with a phase loss. This situation is relatively rare and easy to judge, mainly because there are burnt marks on the line.
Causes of three-phase AC motor insulation: The internal insulation of the motor does not meet the standard, and there is a phase-to-phase short circuit between turns. Or the internal wiring is wrong. This barbecue machine is sometimes easily confused with an overload barbecue machine, and the stator will also burn out, but there are obvious burn marks in the short-circuit part, such as copper molten ore sometimes. The winding part is burned badly. The reasons for the burning of the three-phase AC motor are: 1. The electric motor adopts the delta connection (3 phase) method, and only one phase of the winding can be burned. Use a megohmmeter to measure the insulation damage of one phase of the winding to the ground. 2. The motor adopts the star (y) connection method, and two phases of the winding are burned. You can use a megohmmeter (clock) to measure the insulation damage of the two phases of the winding to the ground.