Motor malfunction repair methods (motor maintenance) :

1, the method of observation. Breakpoint most occurred in winding ends, look have without touch fold, joint the presence of desoldering.

2, multimeter method. Using resistance, to "Y" type of connection to connect a table bar in the center of the "Y" shape, the other in turn in the head end of the three-phase winding, infinite phase has a breakpoint; "Delta" connection type of short connection, measuring winding in each group respectively, infinity to breaking point.

3, try lamp. Method with former, such as bright a photograph for open circuit.

4, megohmmeter. Resistance tends to infinity (that is, not as a zero value) is the cut-off point.

5, current meter method. Motor at runtime, use current meter to measure three phase current, if the imbalance of three phase current and short-circuit phenomenon, and no is a phase winding is part of the current small short circuit fault.

6, bridge method. A phase when the motor is bigger than the other two phase resistance, resistance show that the phase winding part of open circuit fault;

7, current balance method. For "Y" type of connection, but after the three-phase winding parallel, alternating current into the low voltage large current, if the current in the three-phase winding is greater than 10%, one end of the small current for the circuit; For "delta" connection type, the stator winding of a contact apart first, then by interlinked into low voltage high current, one of the small current for open circuit.

8, broken cage detector test. Check, if the broken rotor cage millivoltmeter readings should be reduced.