Effects of transformer oil reconditioning on DGA 1

[maxljahnke]

Hello.

One particular question has tormented me for some time now since I haven't been able to find an assertive answer to it.
How does treating the transformer's oil with a vacuum dehydrator may affect the trend of your DGA, particularly regarding to furan measurements to estimate the degree of polymerization? (effects on combustible gases as well, if any)

 

[prc]

Vacuum dehydration will remove furan and dissolved hydrocarbon gases from oil. But these will again start building up and with in a couple of months(depending on the severity of ageing/fault) the original furan/gas levels will be reached.

 

[oldfieldguy]

Vacuum treatment hugely affects DGA. A good run should bring gases down to near zero.

Of course, you want to get an analysis immediately after treatment and then again in about a month to see what's going on. You can expect gases to remain low if you do not have ongoing problems in your transformer. Moisture, however, may show a significant rise as moisture entrained in your cellulosic insulation migrates out into the oil to reach equilibribrium.

old field guy