How to deal with the fault of three-phase asynchronous motor

Three-phase asynchronous motor in the use of is very convenient, it also because of its own advantages have been recognized by everyone, but the machine in the use of a long time 

after the failure, so it will affect our use, then in this case how do we fault? Xiaobian collated the relevant information, a look.

Winding is a part of the motor, aging, moisture, heat, erosion, foreign body intrusion, external impact will cause damage to the winding, motor overload, undervoltage, overvoltage, lack 

of phase operation can also cause winding failure. Winding fault is generally divided into winding grounding, short circuit, open circuit, wiring error. The fault phenomena, causes and

 inspection methods are described respectively.

Winding ground

Refers to the grounding caused by the winding and the core or the failure of the insulation with the housing.

1. Fault symptom

The case is charged, the control line is out of control, and the winding is short circuited and heated, which makes the motor unable to operate normally.

2. Cause

Damp winding reduces insulation resistance; Long-term overload operation of the motor; Harmful gas corrosion; Metal foreign bodies intrude into the winding and damage the insulation;

 Insulation damage to the core when rewinding the stator winding; Winding end touching end cover stand; Insulation burns caused by rotor friction; The insulation of the lead line is 

damaged and the shell colliding; An overvoltage, such as a lightning strike, breaks down the insulation.

3. Check the method

(1) Observation method. Observe the end of the winding and the insulation in the groove for signs of damage and scorch, if any, it is the ground point.

(2) Multimeter inspection method. Use a multimeter in the low-resistance gear. If the reading is small, it is grounded.

3 megohm meter method. According to different grades, different megohm meters are selected to measure the insulation resistance of each group of resistors, if the reading is zero, it 

means that the winding is grounded, but the motor insulation is damp or due to an accident and breakdown, it needs to be determined according to experience, generally speaking, the 

pointer wobble at "0", it can be considered to have a certain resistance value.

(4) Test lamp method. If the light is on, it indicates that the winding is grounded. If a spark or smoke is found somewhere, it is the grounding fault point of the winding. If the lamp is 

slightly bright, the insulation has ground breakdown. If the light is not on, but the spark occurs when the test rod is grounded, the winding has not yet broken down, but is seriously damp.

 It can also be used to tap on the edge of the cover of the hardwood, knock to a certain place and so on when the light is off, indicating that the current is on and off, then this is the 

ground point.

(5) Current through burning method. With a voltage regulator transformer, after connecting the power supply, the ground point heats up quickly, and the insulation smoke is the ground 

point. Special attention should be paid to the small motor should not exceed twice the rated current, and the time should not exceed half a minute; The large motor is 20%-50% of the 

rated current or gradually increase the current, and the power is off immediately when the ground point is just smoking.

(6) Cluster elimination. If the ground point is in the heart of the iron core and the burn is more severe, the burned copper wire is fused with the iron core. The method used is to divide 

the grounded one-phase winding into two halves, and so on, and finally find the ground point.

In addition, there are high pressure test method, magnetic needle exploration method, power frequency vibration method, etc., not introduced here.

Three-phase asynchronous motor how to deal with the method we have told you in detail in the above article, we can refer to the method in our article when fault handling, it will 

certainly help you.