The criteria for determining if a motor has burned out are as follows:
1 phase loss
reason:
This is generally caused by a missing phase in the power supply (one phase is not powered or the power supply voltage is insufficient), or by contactor contacts not closing, wire connections being broken, loose, or contact points being oxidized.
feature:
One or two phases (4-pole) in the winding turn completely black, indicating symmetrical coil damage and regular phase loss.
2 Overload
reason:
This is generally caused by prolonged overcurrent operation, overheating, frequent starting or braking of the motor, or incorrect wiring (e.g., a delta connection being mistaken for a star connection).
feature:
The entire winding turned black, and the end cable ties changed color, became brittle, and even broke.
3 turns
reason:
Damage to the enameled wire caused during the motor manufacturing process, etc.
feature:
When a winding is partially burned out, usually when the motor cavity is clean, there is only one point of failure.
4 alternating
reason:
The photo separator is not in place, or the photo separator (sleeve) is damaged.
feature:
The two adjacent phases of the motor burned out.
5 ground strikes
reason:
The creepage distance between the coil and the end cover base is insufficient.
feature:
There are burn marks in both the coil and the end cap or between the end cap.
