Vacuum Pressure Gauge on Free Conservator Tank Transformer

[spdave]

Hello All

At one of our Site, we do have Main Power Transformer (This is Free Breather Transformer with COnservator Tank)
On that transformer on top of that, they installed "Vacuum-Pressure Gauge".
Normally this device installed on "Sealed Transformer" to measure "Vacuum or Pressure" inside the transformer.
What is the purpose of this to install on Transformer with Conservator Tank?
Can I test this unit or not? as I am worried about if I open the Side Screw from the Vacuum-Pressure Gauge then Oil will come out??
Please advise. Thanks.

 

[waross]

What is the purpose of this to install on Transformer with Conservator Tank?

Probably an inexperienced designer copied the specs from another transformer installation, and was not aware of the difference between a free breathing conservator and a sealed transformer.
I have seen a few strange things due to copy and paste designing.
(A panel with three artificial neutrals fed from a grounded wye transformer bank.
The same job, the designers had the utility drop the 480 Volt supply transformer taps as far as possible as they had not been able to source 460 Volt transformers for their 460 Volt rated pumps.)
Where were their mentors and who pushed the new kids off the deep end?
Another cut and paste resulted in a 500 KVA prime rated set installed when a 225 KVA standby rated set would have handled the greates load that the facility had experienced since day one.
The gen-set supplier made some negative comments about that one, but the checks were good.
It happens.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[Palletjack]

Is it new? When they are built the tanks are tested before fill up. Could have been it was just left on rather than take it off and plug the hole. Normally they are removed in the field on transformers with a N2 blanket. If I saw on on a transformer like you have I would leave it up there also.

If you open the screw, oil will come out..
Hey, use it for drawing oil samples..

 

[argotier]

What is the purpose of this to install on Transformer with Conservator Tank?

Are you sure that the transformer is free-breathing type? It doesn't have a rubber bag or bladder inside the conservator?

That's the only time I can imagine a pressure-vacuum gauge might be of some use (In IEC world these gauges are never used for transformers with conservator, with or without bladders).

Can I test this unit or not? as I am worried about if I open the Side Screw from the Vacuum-Pressure Gauge then Oil will come out??

Where is the gauge located? I'm assuming somewhere in the conservator?, if any lower the answer is obvious.

FYI: If its located up in the conservator tank and it does have a rubber bag, then oil will come out as the entire conservator is filled with oil.

 

[OffTap100]

Is the gauge/valve located slightly above the conservator tank..or at the end of a pressure relief device?

We have a few units where the pressure relief device is a 6" pipe that is mounted at an angle on top of the transformer, with an emergency glass blow out device. On top of that is a small valve where you can purge trapped air after refilling the unit, and after the conservator tank is filled sufficiently.

Sorry, hard to describe.