Transformer Breather

[AKassem]

For me , I know that the function of the oil Transformer Breather is to prevent water vapour from entering inside the Transformer by using silica gel & prevent dust or soild particles from entering by using some transformer oil in the Breather cup ..

In my case I noticed that the oil level inside Breather cup increases and decreases frequntly .. ( Most probably decreasing at hight ambient temp. in Midday & increasing at low ambient temp. at the early morning) ..

what are the factors that changes the oil level in the Breather cup .. or it should be always nearly constant ?

 

[DTR2011]

Transformer loading has a lot to do with it (temp).

Additionally, pressure has its effects. Remember PV=nRT, from idea gas laws.

 

[prc]

Please see the manual and understand how the oil seal at the bottom of breather is working.Then it will be clear to you why the oil level in the cup is fluctuating.It is because of the pressure difference( over atmospheric pressure) developed inside the breather tube when oil in transformer expands or contracts depending on ambient temperature and oil temperature rise, depending on the load.Oil volume expands by 0.8 % for every 10C temperature rise.