[HELP] Oil Insulated Switchgear.

No joy over the phone with COOPER, then?

If I had to guess, based on your small photo, you have a leak at the shaft of the operating mechanism. The oil staining seems centered around that. I would surmise that maybe the gasketing or packing is deteriorated or loose. However, it would need to be de-energized and investigated to determine if this is the case.

With all of the dirt & debris around the mech box, it's hard to tell if there is rust or corrosion that would be enough to leak through from inside the tank. You need to do a thorough cleaning first to see what is really there. If it were rusting down by that pile of debris, it probably wouldn't be oily up as far as it goes. It rather looks like the debris is dirt & dust that has collected and been glued together by the oil.

Do some investigation and list your possible causes, then get someone in there qualified to fix it.

Do as Mr. T says, but before you drain the tank take a few oil samples just in case you want to test it and see if it deteriorated and why. If it fails a BDV (Break Down Voltage) test then there may be a lot of water or debris in the oil and you have to find out why.

On the other hand it may be cheaper to just replace the entire switch as a unit, time to some cost comparisons of replace vs. investigate & repair.

Agreed! Chemical and physical processes tend toward equilibrium. If oil is getting out, then moisture IS getting in, and will try to balance its relative concentration in relation to the outside. At the very least, don't put the same old oil back in that you take out. Refill what is needed with new, clean insulating oil.

thanks guys,

ill update once the switchger well be in our hand...

What is the right term we can use for the building up of sedimentation (?) of mineral oil in this picture ?Oil is not burnt, just dark on the bottom.