Motor maintenance, high voltage motor winding grounding fault analysis and treatment, with high efficiency, energy saving, low noise, small vibration, light weight, reliable performance, easy installation and maintenance, etc. Since put into operation has been operating normally, but in the last December, in the operation of the motor in protection action, monitoring shows that the motor stator winding grounding signal, a preliminary shaking table measuring cables and electrical insulation, found grounding phenomenon, after we receive the notice, the motor terminal box to solve cable joint, respectively, measure of cable and motor using 2500 v megohmmeter, measured motor insulation to ground is 0.5 M Ω, the cable is 3500 M Ω, it can determine for motor stator winding grounding.
We know that the grounding fault of the motor winding can occur in the following situations:
1. Long-term overload of the motor and insulation aging and deterioration cause insulation breakdown to the ground;
2. Wire lightning overvoltage or operation overvoltage breakdown insulation;
3. When the synchronous motor suddenly disconnects the excitation coil, high-voltage breakdown coil insulation will be generated;
4. Due to conductive dust, creepage distance is reduced, causing breakdown or flashover to the ground;
5. Ventilation groove gasket, finger tooth pressing plate open welding or rivet relaxation, iron core overpressing is not tight, tooth vibration and bending tooth pressing plate scraping and grinding coil insulation, resulting in winding grounding fault;
6. The insulation of excitation coil of asynchronous motor ages and contracts, often vibrates, which causes insulation damage to break down to the ground under frequent starting and braking of the motor;
7. Due to the short circuit of the coil charred insulation, causing a fault to the ground.
