Transformer Leakage

The transformer manufacturer would be the best source of advice.

Because they:

1. Have seen the transformer before

2. Built it and know how much oil they put in it when built

3. Won't have to make wild guesses based on absolutely no credible information provided by you.

4. May have some incentive to help you, which we don't

CALL THE MANUFACTURER OF THE TRANSFORMER!!!!!!!!!!!!!!

Read this

The reason of the transformer oil leakage...

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5. Will have experience elsewhere of other transformer issues pertaining to their equipment that they can bring to the party.

Oh pleaase! Leaky vessel IS a question to this community?!?

You are not making sense. Try some punctuation to define where one sentence ends and another one starts.

Is this an oil filled transformer? Does it have a sign on it saying 'This Way Up'? Please check and report back for further instructions.

I think you have something here. Any fluid filled vessel with a breather vent should have the vent above the fluid line so that air can breathe in and out of the vessel. For fluid to leak out of a breather vent fluid must be at the breather vent elevation. Either the transformer is overfilled, the transformer is not level or in the general case the transformer is oriented wrong.

Great! Now how do we claim our consultancy fee from someone that cannot fix a leak?

the problem is that it might have been over filled from the manufacturer, the second reason is that may in the transportation it have been tilted thus making the oil from the main to find its way to the breather, and also check if your oil bath in the breather is not leaking

Every transformer I've fitted has been delivered with the breather blanked off to prevent oil getting in to the breather in transit.

Assuming that this an oil filled transformer it should have a means of checking the oil level, eg Sight glass. Is the level correct for temperature? Is the transformer on a level base? If it is a plain breather it may have a bung fitted for transport. When removing this you sometimes get oil leaking that has been sloshed about during transport. If the transformer has a tank on the top, the sight glass will be on that, otherwise on the transformer. If oil continues to come from the breather the transformer is over filled. A silica gel filter might be fitted, if so empty any oil from this. If this filter has been filled with oil empty the container, clean out and fit a new filter element.

Some sort of response from you would be in order. Perhaps even thank you to all forum members who have taken the time to respond to your question.

This is an assumption!!!

Transformer was located or stored cold.

Transformer was moved into hot sun.

Transformer oil warmed up and expanded.

Maybe?

Wouldn't you assume that the manufacturer filled the transformer to the level corresponding to the volume of oil with the transformer at operating temperature?

I think this is a reasonable, plausible assumption considering that once again we know absolutely nothing about the transformer environment. The OP hasn't even given us their location let alone anything about this transformer. As far as we know this transformer is built in Russia to "normal" parameters but has been installed in the sun of the Thar desert. Remember we only have the information from somebody that cannot figure out how to diagnose a brand new vessel that leaks.

For all we know it might have been installed upside down.

Doubt it. They wouldn't have been able to read the nameplate.

If they could read the nameplate they'd know who manufactured it and could contact them!

checking the position of the breather.and the oil level from the oil sight glass.Generally the oil leaking do not happen.

Maybe the breather is lower the oil level.

Generally the breather is on the top of the transformer.