Electrical faults in motor operation mainly include interphase insulation fault and ground insulation fault. Three-phase motors may also involve phase insulation faults. Most of the electrical insulation faults of motors are caused by improper handling of manufacturing process, that is, there are quality hidden dangers. Of course, improper use and maintenance in the later period will also lead to failure. Turn-to-turn insulation fault is the damage of turn-to-turn insulation in the same phase coil. The reason for this failure may be the quality problem of the electromagnetic wire itself, and more commonly, it is due to improper operation when the wire is embedded.
Electromagnetic wire insulation layer will cause damage; This type of fault may not be found in winding inspection, and the damaged parts have been repaired to some extent during winding soaking and baking. However, the vibration phenomenon in motor operation is easy to cause turn-to-turn breakdown of insulation damage, especially in the case of poor impregnation effect and large motor vibration, the possibility of failure is greater. Grounding fault is caused by insulation damage between winding and iron core and other related components.
Most grounding faults are caused by insufficient control of production process. Phase-to-phase insulation fault is a unique fault feature of three-phase motors, that is, the phase-to-phase insulation of motor windings is damaged, and most phase-to-phase faults occur at the end of windings, and most of them are 2-pole motors.
Through the analysis of phase-to-phase fault of motor, it is found that the shape and size of phase-to-phase insulation have great influence on the phase-to-phase insulation performance of winding. Especially in the wiring process, the shaping and binding of winding ends directly determine the insulation quality between windings, especially for scattered windings, gravity knocking during the shaping process is the biggest insulation hidden danger between turns.