AC Motor Starting Problems

1. What are the causes of abnormal vibration and sound of the AC motor?

Mechanical aspects:

(1) poor bearing lubrication and bearing wear;

(2) The bearing chamber is too large.

(3) The fastening screw is loose;

(4) There is debris in the AC motor.

Electromagnetic aspects:

(1) AC motor overload operation;

(2) Three-phase current imbalance;

(3) lack of phase;

(4) Short circuit failure of the stator and rotor windings;

(5) The welded part of the cage rotor is broken by welding.

2. What are the causes of AC motor bearing overheating?

AC motor itself:

(1) The inner and outer rings of the bearing are too tight;

(2) There are problems with the shape and position tolerance of the parts, such as the coaxiality of the parts such as the base, end cover and shaft;

(3) improper selection of bearings;

(4) The bearing is poorly lubricated or the bearing is not cleaned, and there is debris in the grease;

(5) Axis current.

Use aspect:

(1) Improper installation of the unit, such as the axial coaxiality of the AC motor shaft and the driven device is not satisfactory;

(2) The pulley is pulled too tightly;

(3) The bearing is not well maintained, the grease is insufficient or exceeds the service life, and the hair is deteriorated.