The direct cause of motor burnout is high temperature.
Common faults in electric motors can be divided into two categories: mechanical faults and electrical faults. Electrical faults include short circuits, open circuits in stator and rotor windings, and faults in starting equipment; Mechanical failures include excessive vibration, overheating of bearings, friction between stator and rotor, and abnormal noise.

Reasons for high motor temperature

1. Internal reasons of the electric motor itself
(1) When installing and repairing an electric motor, the motor winding of the delta connection method was mistakenly connected to the Y-shaped connection method, or the Y-shaped connection method was mistakenly connected to the delta shape.
(2) Short circuits or grounding between windings or turns can cause an increase in winding current, imbalance in three-phase current, and overheating of the motor.
(3) The incorrect connection of the pole group coils or uneven distribution of the number of coils per phase result in unbalanced three-phase no-load current and excessive current; The three-phase current of the motor is severely unbalanced during operation, causing noise and vibration, and overheating of the motor.
(4) Friction heating occurs between the stator and rotor.
(5) The cage rotor conductor of an asynchronous motor is broken, or the winding of the wound rotor is broken. The electric motor overheats due to insufficient output.
(6) The motor bearings are overheated.

2. Reasons for motor load

(1) The motor operates under overload for a long time, causing the stator current to significantly exceed the rated current and overheating of the motor.
(2) Frequent starting, prolonged starting time, or short starting intervals can cause excessive temperature rise in the motor.
(3) Mechanical failure caused by being dragged increases the output of the motor, or it gets stuck and does not rotate or the speed drops sharply, resulting in a sudden increase in motor current and overheating.
(4) The working mode of the motor does not match the load working mode, for example, a motor with a short-term cycle working mode is used to drive a load that operates continuously for a long time.

3. Environmental and ventilation heat dissipation reasons.

(1) The working environment and ventilation of the motor are too high, and the motor cannot receive good ventilation and heat dissipation, resulting in overheating.
(2) Excessive dust and oil stains inside the motor are not conducive to the heat dissipation of the motor.
(3) The lack of wind shield or wind deflector inside the motor leads to poor air flow and poor heat dissipation of the motor.
(4) The fan is damaged, deformed, loose, or not installed or installed upside down, resulting in poor ventilation and heat dissipation of the motor.
(5) There are too many defects in the heat dissipation ribs of the enclosed motor casing, resulting in a reduction in the heat dissipation area; Or blockage of the protective motor fan can cause poor ventilation and heat dissipation of the motor, resulting in excessive temperature rise.