Portable DGA analyser

[etsa]

I’m currently working on a small project to recomend a portable DGA analyser for testing substation transformer oil. I have found information for a Kelman Transport X unit. Does anyone else use this piece of equipment and are you getting good results with it. Also what other units are available and what’s their performance like?

Cheers
Brett

 

[ausphil]

we trialled it, and it returned varying readings for different concentrations of gases, in comparison to our total gas extraction technique. It may perform better in comparison to partial extraction methods. However if you are after trendable results against itself (ie repeatability) it seems like a good instrument. If you wanted to do a conversion from your previous TG extraction ppm figures to the ones given by this unit, you probably couldn't.

The main benefit of this machine we saw was to give an analysis of a transformer after a fault onsite, and to have fairly relaxed limits for pass or fail. Then you would take a sample back to the lab to be done for comparison purposes against previous gas readings.

ausphil

 

[able357]

If your interested in getting the pf and strength of the oil you can use the DGA method but also a method my company uses. We use a test system called a DFR which stands for dielectric frequency response. The way it works is it applies a voltage to with frequency that sweeps from .001 Hz to 1kHz. This test will show moisture, corrosive sulfur and so on! This test is even more impressive when testing the insulation of a power system! If you interested let me konw and I can help you! One more thing we do use a portable DGA set but also send it out for further analysis to weed out errors!

 

[olicg]

I have used KELMAN Transport X.

Its an excellent device which is maintenance free when you compare it with a GC. Moreover, unlike GC, Kelman PAS technology has made DGA a very portable and compact instrument. It can be easily moved around.

I also agree with ausphil that its an ecellent device for continuous monitoring or trending. Even otherwise it is good. As far as i remember it comes with Key gases + moisture combination.

It is also important that you buy the complete analysis software of Kelman which will make your life easy. It can assist you in analysing results based on IEEE key gas method, Duval traingle and other techniques.

Olic