Generator Collector Rings 4

[electrageek]

We have an older GE Generator (70MW) that is being put back into service. The collector rings have some rust on them but it can be clean off easily. My question is at what point should we consider replacing the collector rings. It is very expensive and I would like to know what the criteria should be. Any Generator experts out there.

 

[edison123]

slavag

The answer to your OT question.

It is the flux loop test to check the integrity of the stator core lamination insulation by magnetizing the core off-line. The test involves passing 80 to 100% working flux in the core and checking for "hot spots" in the core. Any spot having more than 10 deg C higher than average temp. is considered hot spot and requires rectification works, which may even involve dismantling the laminations.

It is a routine test on an empty core prior to a new winding/ rewind. It is an condition assessment test on wound machines.

 

[electrageek]

Byrdj

This machine has four collector rings 2 per phase + -. The OD with a Pi tape is 12.548, 12.740, 12.740, 12.781. Its the first one that they are saying can't be re-grooved (12.548)

The groove depth is 0.021 to 0.016 on the bad one.

 

[wolf39]

Slava:

Electrageek is right. You should start a new thread on the core magnetization test, despite the fact that edison123 has already responded to your question competently.

Wolf

http://www.hydropower-consult.com