Effect of improper storage of oil-filled potential transformer

[GRAEE]

We have a 80,500:115 V oil-filled potential transformer stored horizontally instead in vertical position for almost 13 years already.

What are the possible effects/problems may encounter on the performance of the PT when not properly stored? Does it affects the insulation or accuracy of the PT?

Hope you can share your experiences on this situation.

regards,

GRAEE

 

[waross]

The possible problems are a loss of oil or the ingress of moisture. Accuracy should be OK. A low oil level may lead to destruction by internal flashover. Moisture may lead to early failure due to insulation degradation.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[ausphil]

You may also have voids in the paper/oil bushing when you turn it upright (depending if the paper was sitting below the oil level when horizontal), which could lead to PD issues. This can be due to draining oil out of the paper for so long.

I'd give it a PD/DDF test prior to service, and analyse an oil sample to determine if you have moisture ingress.

ausphil