)/Contents(None of the form fields on this page have descriptions. If it does not change with the change of the power supply, the one-phase winding of the larger current will be short-circuited.None of the form fields on this page have descriptions. In no-load operation of the motor, the three-phase current is measured first, and then the two-phase current is measured and compared. A group of short circuit faults with low voltage are detected. Three windings are connected in series and connected to low voltage safe alternating current. Measuring the insulation resistance between any two-phase windings, if the reading is minimal or zero, shows that there is a short circuit between the two-phase windings. If the difference exceeds, there will be short circuit fault in the phase with small resistance. When measuring the DC resistance of each winding, the difference should not exceed 5%. Measured by ammeter, if the current of a phase is too large, it indicates that there is a short circuit in the phase.
Running without load for 20 minutes (stop immediately when abnormal is found), touch each part of the winding with the back of your hand to check if it exceeds normal temperature. After the winding is overheated, it leaves dark brown and has a peculiar smell.
Observe whether the junction box and winding end are burnt or not. (7) Metal foreign materials fall into the motor and oil stain is excessive. (6) Insulation damage caused by rotor sweeping heat.
The gradual build-up of heat inside the coil winding may, in time, damage the coil insulation. The extra heat generated during inrush periods cannot escape fast enough. This causes the windings to heat up, which is a negative phenomenon. Since the inrush current may be up to 5 times the holding current, a standard AC coil on an air-gap solenoid may overheat and burn out if required to cycle too frequently. (5) Insulation damage is caused by friction between rotor and stator winding ends. Three-phase squirrel cage induction motor consists of a rotor and a stator with. (4) Insulation breakdown due to overvoltage or lightning strike. (3) The damp winding reduces the insulation resistance and causes insulation breakdown. (2) Insulation damage caused by wire insertion. If the switch fails open, the motor wont start, the run winding will overheat, turns will short together and smoke will ensue. (1) The long-term overload of the motor causes aging of the insulation. Reasons for Short Circuit Faults of Motor Windings
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