winding failures,electric motor rewinds

winding failure

The photos below are typical winding failures in three phase stators. Along with the photo is a brief explanation of the cause of the problem. For a more detailed answer to your questions please feel free to contact us by using the contact page or call

First Electric Motor Service Inc.

73 Olympia Ave Woburn Mass 01801

Tel. 781-937-0226

Fax. 781-938-3557

(click on stator to see larger version)

winding failures,electric motor rewinds

winding failure

A single phased winding failure is the result of an open in one of the phases that supply power to the motor. The open is usually caused by a bad fuse,bad connectiion ,a open contactor or a broken power line.


winding failures,electric motor rewinds

winding failure

winding failures,electric motor rewinds

winding failure

fe-mot-bad-7_small.jpg (2941 bytes)

fe-mot-bad-8_small.jpg (3017 bytes)

These six photos show insulation failure typically due to vibration,voltage surge, abrasives,contamination by hostile enviroments.


fe-mot-bad-9_small.jpg (2817 bytes)

Thermal deterioration of insulation in one phase of the winding can result from unequal voltage between phases. Unequal voltages usually are caused by unbalanced loads on the power source,a poor connection at the motor terminal,or a high resistance contact. NOTE: A one-percent voltage unbalance can result in a six to ten percent current unbalance.


fe-mot-bad-10_small.jpg (2757 bytes)

Thermal deterioration of the insulation in all phases of the stator winding typically is caused by load demands exceeding the rating of the motor. NOTE:Under-voltage and over-voltage(exceeding NEMA standards)will result in the same type of insulation deterioration.


fe-mot-bad-11_small.jpg (2890 bytes)

Servere thermal deterioration of the insulation in all phases of the motor normally is caused by very high currents in the stator winding due to a locked rotor condition. It may also occur as a result of excessive starts and reversals.


fe-mot-bad-12_small.jpg (3067 bytes)

Insulation failures like this usually are caused by voltage surges. Voltage surges are often the result of switching power circuits,lightning strikes,capacitor dishcharges and solid-state power devices.

easa2.gif (1609 bytes)



sales@firstelectricmotor.com

First Electric Motor Service Inc
73 Olympia Ave Woburn Mass 01801
Tel 781-937-0226
Fax 781-938-3557