Motor Vibration,high peak of 9.78 mm/s at exactly 100Hz
Motor Vibration,high peak of 9.78 mm/s at exactly 100Hz
(OP)
Hi Guys,
I have a new motor we put into service 1 week ago, we took out the original to replace bearings as it had been working for 5 years (routine service). This motor has shown up the following after routine condition monitoring:high peak of 9.78 mm/s at exactly 100Hz (twice line frequency) measured at the motor drive end in the horizontal plane(pump and motor laser aligned.) Do you have any ideas as to what maybe causing this (could it be a stator problem).
Thanks
I have a new motor we put into service 1 week ago, we took out the original to replace bearings as it had been working for 5 years (routine service). This motor has shown up the following after routine condition monitoring:high peak of 9.78 mm/s at exactly 100Hz (twice line frequency) measured at the motor drive end in the horizontal plane(pump and motor laser aligned.) Do you have any ideas as to what maybe causing this (could it be a stator problem).
Thanks





RE: Motor Vibration,high peak of 9.78 mm/s at exactly 100Hz
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RE: Motor Vibration,high peak of 9.78 mm/s at exactly 100Hz
Much less likely candidates – unbalanced voltage, winding problem, as-built air-gap problem. One other easy thing to check that might indicate unbalanced voltage or winding problem would be a check of current balance.
(Again the number one suspect is foot conditions.)
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Eng-tips forums: The best place on the web for engineering discussions.
RE: Motor Vibration,high peak of 9.78 mm/s at exactly 100Hz
If the frequency is twice motor speed, look for a mechanical or balance problem. If it is twice line frequency look for a stator problem or some problem in the magnetic circuit.
The slight difference between line frequency and motor speed is significant.
respectfully
RE: Motor Vibration,high peak of 9.78 mm/s at exactly 100Hz
Yes it is a 2pl in 200 frame, the point is, it is at exactly 100hz.
RE: Motor Vibration,high peak of 9.78 mm/s at exactly 100Hz
respectfully
RE: Motor Vibration,high peak of 9.78 mm/s at exactly 100Hz
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RE: Motor Vibration,high peak of 9.78 mm/s at exactly 100Hz
RE: Motor Vibration,high peak of 9.78 mm/s at exactly 100Hz
Is the motor you replaced identical in spec and manufacture as the one you removed?
Slim one this one, but worth a comment: If it is a different manf (meaning: you didn't have this problem before) then you can get a phenomena called "beat" at line frequency (50Hz) or direct multiples of this (100Hz, 150Hz), especially if the motor is of low quality (low copper content etc). It's difficult to overcome sometimes other than changing the motor make or perhaps adding an output reactor.