Hi

The transformer oil DBDS and CCD test are showing different results.

We conducted DBDS and CCD test to know the oil condition in our transformer. The DBDS test shows very high results whereas CCD test shows that the oil is non corrosive. What should be done in such situation?

 

Paru...

were the tests performed by the same testing firm, or were they performed by your own Lab specialists?

Regards,
Phil Corso

 

yes, two different labs were consulted.

 

Paru...

you probably know that high oil or winding temperature is a precursor to evidence of DBDS!

Was the high temp condition noted in the DGA test that preceded the DBDS test?

Phil

 

Paru...

did both firms reach the same result, i.e., copper corrosion confirmed with DBDS test, but none using CCD test?

Phil

 

yes, correct. we can not doubt on the procedure and equipment of the both labs as we sent samples of other transformers and they are ok.

 

Paru... do you know the sequence of tests?

1) Were the DBSD and CCD tests taken at the same?

2) Did both Contract Labs carry out the two tests at the same time?

3) Is it possible that an attempt was made to mitigate the condition between tests?

4) Have the same tests been carried out on samples of unused transformer oil?

Phil