What should I do if the motor become hot? (1)

2022-09-17 17:46

What should I do if the motor become hot? (1)

Wuxi Sanda Motor will teach you what should you do if your motor become hot(1)

1. The air gap between the stator and rotor of the motor is small, which simply leads to the collision between the stator and the rotor.


For medium and small motors, the air gap is generally 0.2mm to 1.5mm. When the air gap is large, the excitation current is required to be large, which then affects the power factor of the motor; if the air gap is too small, the rotor may collide each other. Generally, due to the severe out-of-tolerance of the bearing and the wear and deformation of the inner hole of the end cover, the different axles of the base, the end cover and the rotor cause the sweeping, which can easily cause the motor to become hot or even burn out. If the bearing is found to be worn, it should be replaced in time, and the end cover should be replaced or brushed. The simpler solution is to insert a cushion on the end cover.

2. The abnormal vibration or noise of the motor simply causes the motor become hot.

This situation is attributed to the vibration caused by the motor itself, mostly due to the poor dynamic balance of the rotor, as well as poor bearings, bending of the rotating shaft, different axial centers of the end cover, base and rotor, loose fasteners, or uneven foundation of the motor device, and the device is not in place. It may also be caused by the mechanical end, which should be eliminated according to the specific situation.

3. The bearing does not work properly, which will cause the motor to heat up

Whether the bearing works normally can be judged by hearing and temperature experience. You can check the bearing end by hand or a thermometer to determine whether its temperature is within the normal range; you can also use a listening rod (copper rod) to touch the bearing box. If you hear an impact sound, it means that one or several balls may be crushed. When there is a sizzling sound, it means that the bearing oil is lacking, and the motor should be replaced with grease every 3,000 to 5,000 hours of operation.

4. The power supply voltage is too high, the excitation current increases, and the motor is prone to overheating

Excessive voltages can compromise the motor insulation, putting it at risk of breakdown. When the power supply voltage is low, the electromagnetic torque will be reduced. If the load torque is not reduced and the rotor speed is too low, the increase of the slip ratio will cause the motor to overload and heat up, and the long-term overload will affect the life of the motor. When the three-phase voltage is asymmetric, that is, when the voltage of one phase is high or low, the current of a certain phase will be too large, the motor will heat up, and at the same time, the torque will be reduced, and a "humming" sound will be emitted, and the winding will be damaged for a long time.


In short, no matter the voltage is too high, too low or the voltage is asymmetrical, the current will increase, the motor will heat up and the motor will be damaged. Therefore, according to the standard, the change of the motor power supply voltage should not exceed ±5% of the rated value, and the motor output power can maintain the rated value. The motor supply voltage should not exceed ±10% of the rated value, and the difference between the three-phase supply voltages should not exceed ±5% of the rated value.