Motor Failure Problem-Need Some Advise
Motor Failure Problem-Need Some Advise
(OP)
What would be other posible cause of motor winding to be cut (lower winding part of the stator was cut, and the stator core lamination welded)
motor passed the following test
1. rotor bar crack
2. core/ring hot spot test
3. surge
4. ir
5. no load (current voltage vibration)
and at commissioning with load, the motor failed!
during commissioning, no over load and no overheating was detected
motor passed the following test
1. rotor bar crack
2. core/ring hot spot test
3. surge
4. ir
5. no load (current voltage vibration)
and at commissioning with load, the motor failed!
during commissioning, no over load and no overheating was detected
GO PLACIDLY, AMIDST THE NOISE AND HASTE-Desiderata





RE: Motor Failure Problem-Need Some Advise
RE: Motor Failure Problem-Need Some Advise
My guy informed me that the motor fails while under load? I will verify if they have conducted a no-load test prior to it?
GO PLACIDLY, AMIDST THE NOISE AND HASTE-Desiderata
RE: Motor Failure Problem-Need Some Advise
Possibly a fan failure, possibly some foreign object found its way into the air gap and dragged some stator laminations. Bearing failure can cause this type of failure and I have seen bearings fail on new machines.
respectfully
RE: Motor Failure Problem-Need Some Advise
Did it fail immediately upon start? Did it get up to speed? Did it fail sometime after start?
What do you mean by lower part of the winding? Are you talking about the bottom endwindings in vertical motor? Bottom coil in a slot?
What is the approx motor horsepower and speed and voltage? At least this will tell us if this is random or form wound machine.
Is there a vfd feeding the motor? Any strange reduced voltage starting means?
What do you mean by cut? Was copper exposed? Did it look like a mechanical cut?
What do you mean by core welded...is it at the same location where the coil is faulted? Is there any ground fault protection associated with this motor? Did the motor trip on ground fault or instantaneous overcurrent?
Have you traced the location of the failure in relation to the line end coil?
=====================================
Eng-tips forums: The best place on the web for engineering discussions.
RE: Motor Failure Problem-Need Some Advise
=====================================
Eng-tips forums: The best place on the web for engineering discussions.
RE: Motor Failure Problem-Need Some Advise
before testing PI and IR ok
We conducted at no load test (1-hour) the following
1. vibration ok
2. current logged ok
3. Temp ok (body using IR camera) every 15 min
it also passed core test (stator core lamination no hot spot detected)
4. Voltage acceptable (unbalance would just add 1 deg C temp rise as per my computation)
During load test:
1. pulley lazer aligned
2. phase current 90% FLA
3. Voltage acceptable (unbalance would just add 1 deg C temp rise as per my computation), about 6V highest voltage difference (our supply is 480v)
4. Vibration within standard
5. Temp ok
6. Motor failed after running 30 min
Motor failed after 7 months running, the above are conducted after the rewinding
By the way, 3 other identical motor were rewinded with same reading and data of this motor that failed, those other 3 passed.
motor is squirrel cage induction
Motor started by soft starter
GO PLACIDLY, AMIDST THE NOISE AND HASTE-Desiderata