Oil Circuit breakers

Does any body have any experience in carrying out maintenance on oil circuit breakers?
With regards to the testing the oil
· Di-electric test
· Crackle test
· Acid content of the oil

Also cleaning the different parts what type of cleaning agent shown you use when cleaning the different parts.
Any info on maintaining oil circuit breakers is greatly appreciated.
paul

 

[buzzp]

Paul55, Are these similar to the old dashpots that used to be used for overload conditions?

 

[dpc]

I don't have any direct experience, but any of the HV maintenance outfits should be able to give you information.

Try

http://www.avopower.com

or contact GE or ABB service centers.

 

[electrageek]

paul55

Another excellent source of testing information for all kinds of electrical testing is NETA. The can be found at

http://www.netaworld.org

They have a complete lists of tests for almost all types of electrical equipment.

 

[stevemcg]

are these OCB'S the BVP 17 type

 

[alex444]

Generally speaking,

Di-electric Test.- want to perform this test on a periodic basis or after 2-3 fault interruptions ... depends on the severity of the fault. The fault will create carbon particles lowering the dielectric breakdown. Along with di-electric you should do oil Power factor and IFT testing .

Crackle Test.- Am not familiar with it.

Acid Test.- Generally not an issue with OCB's , since there is no paper cellulose as in XFMR's.

Cleaning agents.- Internal cleaning using alcohol for the most part is an adequate cleaner. As for external cleaning of the bushings, use Collonite (spelling?).

OCB maintenance.- Power factor testing, contact resistance and timing (travel time) are the most test for OCB's, there may be additional tests depending on the equipment classification, medium vs high voltage.

Hope this helps

 

[powrgen]

I broadly agree with Alex, not totally convinced that alcohol is best though I've never tried it. Make sure any cloth/wipers are lint free.
The crackle test involved heating a wire and dipping it into the oil and checking the 'crackle' as a method of testing for moisture. Haven't used it for years now, buy a decent moisture meter it could save you a lot of heartache.