hi All, can anyone maybe help me with a little problem i have. my gas sample reads very low but gives a problem reading of "possible thermal fault of high temp" "possible thermal decomposition of the cellulose due to high temp (hot spots and arcing)" and at the same time the Rogers ratio read Normal Ageing.... the Gases are as follows:
Hydrogen 8 ppm
Oxygen 11672 ppm
Nitrogen 32480 ppm
CO 6 ppm
CO2 109 ppm
Methane 1 ppm
ethylene 1 ppm
ethane 1 ppm
Acethylene 0 ppm
TCG 17
TGC 4.43%

This is the first sample for the transformer so i do not have a history to compare it with. The owner of the transformer wants to know WHY is there a problem reading if there is hardly any gas in it?? ANYONE have an answer for me please let me knw

I agree with your assessment. The sample doesn't show any problems at all with this transformer! (*)

I'll bet this diagnostic message resulted from applying a ratio method such as Roger's Ratio or Dorenburg (sp?). But those methods are not supposed to be used until the levels get high enough (above condition 1 levels of IEEE 57.104 - for example 100ppm H2) and therefoere shoudn't be used with this sample.

If possible I would talk to whoever generated that diagnostic message or originator of the program that generated the diagnostic message. Ask them to explain it. There are two possible outcomes of the conversation, which are both good:
1 - we're both missing something. Good to find out.
2 - The program is screwed up. Good for them to find out.

The 2nd outcome is much much more likely imo.

* - Actually the ratio of O2 to N2 is a little higher than I'd expect. It might be an indication of air leaking in somewhow. But #1 - that has nothing to do wtih the diagnostic message, and #2 - This is absolutely no reason for concern unless the sample shows moisture... which I assume it didn't.

This message has been edited. Last edited by: electricpete,