White powder in generator stator
White powder in generator stator
(OP)
Dear all. On iste we have a 324 hydrogen cooled generator of GE. During last outage we opened the end shields, GE made the MAGIC inspection and also inspection on the stator. It was found signs of white powder on the end windings. It was all over the end windings where some type of tightening material is used to keep the windings attached.
I have seen some comments on the old thread thread605-148662: White dust inside generator.
Can you give me some idea for a possible casue? I suspect that the specific tightening material is not the fit for purpose one.
I have seen some comments on the old thread thread605-148662: White dust inside generator.
Can you give me some idea for a possible casue? I suspect that the specific tightening material is not the fit for purpose one.





RE: White powder in generator stator
There is a lot of information in the trade publications and technical literature about corona. I'd suggest that you do some googling or research on the topic. I think you will be disheartened by what you will find.
rmw
RE: White powder in generator stator
RE: White powder in generator stator
RE: White powder in generator stator
To distinguish you need to look closely at the pattern. PD will have patterns that can trace to voltage stress. For example stronger phase-to-ground pd at line-end coil and possibly stronger phase-to-phase pd between pole phase groups (that's a little trickier). Abrasion would be more uniform.
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RE: White powder in generator stator
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Eng-tips forums: The best place on the web for engineering discussions.
RE: White powder in generator stator
I picked up a brochure from www.agtservices.com at a recent trade show dealing with dusting due to abrasion and showing examples of corona dusting vs abrasion dusting, but I don't see it on their website. You may be able to contact them and get one sent to you.
rmw