EDM in FHP split phase induction motors?
EDM in FHP split phase induction motors?
(OP)
I do lots of work on EDM (bearing currents) in large AC induction and synchronous machines and also DC motors. Coupling mechanisms and failure mechanisms are well understood and most situations can easily be handled. Sometimes at a cost. But so far, all cases I have been in contact with has been solved.
Now, I start to see EDM also in FHP split phase motors. I can explain why we have it, but the problem doesn't seem to be severe enough for anyone to care. My question is, thus:
Do you know about any situations where motors fed from Line-Neutral or Line1-Line2 have unexpectedly short bearing life?
There may also be anecdotes about motors emitting HF interference even if they are constant speed (no VFD).
Now, I start to see EDM also in FHP split phase motors. I can explain why we have it, but the problem doesn't seem to be severe enough for anyone to care. My question is, thus:
Do you know about any situations where motors fed from Line-Neutral or Line1-Line2 have unexpectedly short bearing life?
There may also be anecdotes about motors emitting HF interference even if they are constant speed (no VFD).
Gunnar Englund
www.gke.org
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Half full - Half empty? I don't mind. It's what in it that counts.





RE: EDM in FHP split phase induction motors?
http://www.gke.org/presentatiofner/files/GE%20Bear...
Our plant has many single phase motors, but none are powered off three phase system line-to-neutral or line-to-line.
I think it would apply also for household 120 vac motors powered line to neutral where neutral is grounded at service entrance (center tapped 240vac)?
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(2B)+(2B)' ?
RE: EDM in FHP split phase induction motors?
Gunnar Englund
www.gke.org
--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.
RE: EDM in FHP split phase induction motors?
It makes it all the stranger that we don't hear more about it (as you've mentioned). I've certainly never heard of it. I'll look forward to learning more as you (hopefully) present your findings/conclusions to the forum at some point.
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(2B)+(2B)' ?
RE: EDM in FHP split phase induction motors?
There is probably more emission below that frequency band, but the victims were in the "aeronautical band". I will certainly be on my toes!
Anyone else seen this?
Gunnar Englund
www.gke.org
--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.