3 phase induction motor can not start reason
hen many companies use the 3 Phase Induction Motor will encounter the motor can not start the fault, is the three-phase induction motor burn it? Or the line is broken, the motor is still complete? Is the motor overloaded? How to detect 3 phase induction motor can not start the cause of the malfunction?
Langrui Electric Motor Manufacturers based on many years of manufacturing experience, 3 phase induction motor can not start the following general situation:
1, 3 phase induction motor does not turn and no sound:
If the three phase voltage is balanced, then the fault can be detected in the motor itself, the resistance of the three phase winding of the motor can be detected, to find out the windings disconnected.
2, 3 phase induction motor slow and buzzing:
This failure manifests itself as axial vibration. If one phase current is measured as zero and the other two phases greatly exceed the rated current, this indicates that the two phases are operating due to the circuit or power supply one-phase open circuit or the three phase asynchronous motor winding One-phase circuit. Small capacity motors can be directly measured with a multimeter off. Medium-capacity motor due to the use of multiple windings and multiple windings in parallel, of which if the number of broken or disconnect a parallel branch to check up more trouble, this situation is usually phase current balance method or resistance method . Resistance method of measuring the resistance of the three-phase winding with a bridge, such as three-phase resistance difference of more than five percent, a larger phase resistance for the open phase.
3, 3 phase induction motor does not turn but there is a buzz:
Measurement of motor terminals, if the three-phase voltage balance and rated voltage value, can be judged to be a serious overload, check the steps: first remove the load, then the motor speed and sound normal, you can determine the overload or mechanical part of the load failure, if If the three-phase current is balanced but larger than the rated value, it means that the mechanical part of the motor is stuck, which may be caused by lack of motor Oil, bearing rust or serious damage, cover or oil cap installed too oblique, the rotor and the bore collide (breech) When the motor shaft by hand to a certain angle to feel more strenuous or periodic Scratch sound, can be judged as swept broom.