transformer oil analysis generally gives indication of minor fault or start up of fault inside the transformer. In case of severe faults buchollz or pressure relief valves are operated depending on nature of fault and amount of gases evolved.

My question here is if any particular gas for example acetylene shows sudden steep compared to old trends and crosses the limit set by IEEE or others. Upto what value above limit, can we run the transformer without stopping it?

 

AryanPanthri...

DGA values alone aren't necessarily a good measure of oil integrity! Trends in a year's time might be indicative of normal aging of oil! On the other hand, an increase of 10% in a month might be a sign of an incipient fault!

Often, the ratios of gas constituents are more revealing! Do you have coincident values for the combustible gases, i.e., Hydrogen, Methane, Ethane, and Ethylene, as well as CO?

Also, please provide the Xfmr's size!

Regards,
Phil Corso