HIGH SPEED ROTOR
HIGH SPEED ROTOR
(OP)
What side bands do I look for when analyzing a 3600RPM 500HP 480V refrigeration motor. The problem is intermittent but it is an old motor which has been rebuilt at least three times.
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RE: HIGH SPEED ROTOR
Gunnar Englund
www.gke.org
RE: HIGH SPEED ROTOR
Oh and by the way, to a rotating machinery vibration guy 3600 is not considered "high speed." I mess with turbo compressors with speeds up to 35000 rpm, now that is high speed....
-The future's so bright I gotta wear shades!
RE: HIGH SPEED ROTOR
RE: HIGH SPEED ROTOR
I think is better to check the Instantanous current set of main breaker because the trip could be caused by Inrush, another think to check is if the time elapsed from wye to delta is too short.Also tigh all connection screws.
If you suspect something wrong on the rotor ,for a 60 Hz Supply, perform a vibration analysis and look for 7200 CPM Frecuencies and cut off the current, if vibration stop at the instant the motor is de-energized, then the cause could be electrical.
An electric motor with a damage in the rotor“s squirrell cage will drawn higher current and runs slower than Rated values.
Another test you could perform are : Stray Flux pick Up Coil
and Motor current monitoring System.
Best Regards
PETRONILA
RE: HIGH SPEED ROTOR
RE: HIGH SPEED ROTOR
These type problems are expected to be intermittent because they can depend on the phase angle at time of start.
There are a lot of subtleties in the setup of a wye-delta start which I am not familiar with. They have been discussed on this forum. (open-tranisition, closed transition, resistor value, time delay, how close is motor to being up to speed at time of transisition).
At any rate, I would recommend you re-post this thread with a title something like "motor trips during wye-delta start"
I guarantee you will get a lot of great responses from Marke, jraef, skogsurra and the other control guru's.
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RE: HIGH SPEED ROTOR
RE: HIGH SPEED ROTOR