strange noise from transformer, partial discharge?

[JLuc]

Hi all,

I have been asked to investigate a strange noise coming out of three 3MVA 25kv/600v oil immersed transformers.

There is a small noise coming out of the transformer, like a "ting-ting-ting...", about 160 times a minute.

three out of four transformers are doing it. They are all exactly the same transformer.

Is it possible that partial discharge causes this noise? (it seems to come from inside the tank)

We did gas analysis and everything looked fine exept CO and CO2 were a little high.

thanks for your comments.
JL

 

[oldfieldguy]

JLuc--

I don't know that I'd wait six months on the next DGA.

As for locating the source of the sound, you might jump disciplines and see if your MechE folks have a good sonic fingerprinting contractor. I have heard of some interesting findings of transformer noise signatures done by a vibration analyst who was playing around with his technology.

old field guy