Oil testing 46kv transformers

[oysterpotpie]

How often should we test the oil in our 46kv oil filled transformers? In the past we have always tested them annually. Is that frequency really necessary? Can we safely test the oil every 2nd or 3rd year?

 

[wbd]

What kind of oil testing are you doing? If it is just DGA, that is typically done yearly and full screens done 3 - 5 year cycle depending on the transformer.
It is not alot work or expense to do a DGA for the value you receive.

 

[Zogzog]

I agree with wbd. I suppose you could "safely" test your oil every 3 years the same as you can "safely" see a doctor for a check up every 3 years, you find a problem after 3 years it may be too late.

 

[oysterpotpie]

Thanks for the help guys.

 

[ScottyUK]

Depends on how critical your transformer is. We were sampling a GSU transformer on a monthly basis at one stage after routine DGA picked up a small but hot fault. After a year or so we were happy that the fault was relatively stable; it has so far proven impossible to locate too. The gassing rate has remained steady for years but we were a little nervous when we first identifed the problem so we monitored it closely until we saw that it wasn't deteriorating.


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