CAT Generator Current Unbalance Question
CAT Generator Current Unbalance Question
(OP)
During testing CAT noticed a small load unbalance on our generator and I wanted to get thoughts on this. The CAT technician seemed to think it might cause premature wear on the generator eventually. They said typically they did not get too concerned unless the imbalance was over one hundred amps. The readings were as follows:
Phase A- 865-870Amps
Phase B- 815-820Amps
Phase C- 800-805Amps
Anything to be concerned with? A penny for your thoughts!
Phase A- 865-870Amps
Phase B- 815-820Amps
Phase C- 800-805Amps
Anything to be concerned with? A penny for your thoughts!





RE: CAT Generator Current Unbalance Question
If you do a search for generator negative sequence current, you will probably find more info.
David Castor
www.cvoes.com
RE: CAT Generator Current Unbalance Question
I generally would not worry about the imbalance as long as the amps are within the gen rating.
Rafiq Bulsara
http://www.srengineersct.com
RE: CAT Generator Current Unbalance Question
Frankly I don't see a problem in the numbers provided. The imbalance could be a function of the load, but can also be from the generator itself depending on the frame size and if it has what we called a "square lam" stator. Square lamination stators were built to reduce lamination steel waste, mostly in generators used for standby service. They are fairly easy to identify, the no load rated voltage varies as much as 2% phase to phase. The only time it has caused us any problems is in some parallel island mode applications we had some circulating current issues.
Most CAT tail ends have stator RTD's or TC's installed, if the dealer or you continues to be concerned, monitor the stator temps. The limits are also published in the TMI data sheet for the specific generator.
Hope that helps. Mike L.
RE: CAT Generator Current Unbalance Question
While this may indicate the severity of less than ideal conditions, beware. It seems that every year machines are built with less iron and copper for a given rating. A new machine may not stand abuse as well as a similar ten year old machine.
Bill
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"Why not the best?"
Jimmy Carter
RE: CAT Generator Current Unbalance Question
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If we learn from our mistakes I'm getting a great education!
RE: CAT Generator Current Unbalance Question