Will there be any difference in vac

[vipineng]

Will there be any difference in vacuum reading(in Macleod guage) while connecting the guage to top and bottom sampling valves of transformer??

 

[collies99]

The difference will be the head pressure of the oil.

You can have negative pressure at the top but still have positive pressure at the bottom.

All the side mounted pressure gauges that I have seen on sealed transformers are installed near the top, in the gas space.

You can actually take an oil sample at the bottom under negative pressure at the oil head pressure is about .5 psi/foot? of oil head.

 

[prc]

No difference in vacuum reading whether read from top or bottom sampling valve. To my knowledge, we cannot use Macleod under oil.

 

[vipineng]

The transformer is not filled with oil.I was checking the pressure while vacuuming the unit