Consequence of Leak from main transformer tank to DETC Compartment

[Beengineer]

One of our transformer has the leaks from main tank to the DETC compartment, likely the Barrier board between LTC & main tank failed due to faulty gasket.

What's the consequence if we leave it un-fixed soon?

Thanks

 

[Zogzog]

Depends on what type of tank design you have.

 

[dpc]

I'm confused. The DETC and LTC are two different things in two different locations, aren't they?

David Castor

http://www.cvoes.com

 

[Beengineer]

They are different, I made a typo.

 

[dpc]

So your concern is leakage into the LTC compartment from the main tank?

I would discuss with the LTC manufacturer and transformer manufacturer. But probably you can live for a little while like this.

David Castor

http://www.cvoes.com

 

[electricpete]

I always assumed the LTC was separated from the main tank to protect the winding from the nasty stuff generated in the LTC that can make the LTC oil turn darker (carbon particles?). I imagine it wouldn't be good for that nasty oil to soak into the paper insulation.

=====================================
(2B)+(2B)' ?

 

[waross]

I would expect no issues with transformer oil leaking into the on-Load Tap Changer.
I would expect transformer failure in days or possibly hours if contaminated LTC oil leaks back into the transformer.

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

 

[Beengineer]

I am sorry, I made the typo, it's DETC, not LTC compartment.

 

[electricpete]

For our transformers the DETC is in the main tank and LTC if present in a different compartment. You have DETC in different compartment?

=====================================
(2B)+(2B)' ?

 

[Beengineer]

The leak has been lasted for many years. And the DGA result shows normal.

 

[Beengineer]

Yes it is. And it's with a liquid level gauge (always pointed to the max).

SInce DETC is in the main tank for some models, does this indicate it will be ok if liquid leaks from main tank to the DETC compartment?

 

[dpc]

I've never seen a de-energized (off-load) tap changer in a separate compartment with a barrier. Maybe you need to review the terminology and make sure you are describing the situation and components correctly. Normally, separate compartments are for on-load tap changing mechanisms (LTC)





David Castor

http://www.cvoes.com

 

[Beengineer]

I attach the picture.

The compartment is called: Load Ratio Control Mechanism - Tap selector Compartment.

THe Liquid Lvl Gauge is for this compartment.

 

[Beengineer]

Picture attached.

The compartment is called: Load Ratio Control Mechanism - Tap selector Compartment.

THe Liquid Lvl Gauge is for this compartment.

 

[stevenal]

The key word is load. The taps change under load, so there is arcing occurring in the oil. LTCs are usually free breathing, so moisture level is much higher. You do not want this dirty wet oil in your main tank.

 

[Beengineer]

Steven, it's a DETC transformer

 

[stevenal]

Perhaps your transformer also has a de-energized tap changer on the primary winding. The compartment that you identified as "load ratio control - Tap selector" is also known as an on-load tap changer.

 

[stevenal]

It's a rather important distinction to understand. The consequence of not knowing could be fatal.

 

[Beengineer]

Thank you Steven,

Yes you're right, the "On Load Tap Changer" is on the X side. It's my mis-understanding to identify it as the DETC.

So we may put in this way?

- The compartment of OLTC is much less sealed. There is no much acr generated in that compartment (not much comtamination), since it has never been operated. But if it starts to be operated, serious contamination will occur, and it can do the real damage to the transformer.

 

[stevenal]

Never? Sounds like a long time for a transformer that does not appear to be very new. Voltage regulating controls are and have always been locked off? I'd be hesitant to trust the expense of a transformer to hearsay. Test the oil to confirm.
In my experience, the locked off LTCs collect just as much if not more moisture than those running in automatic.