I would not discuss the causes. I want to discuss the maintenance. In our utility, we have two years program to make Preventive Maintenance. One of the tests is to measure the power factor (pf). If there is any increase of pf reading, then there is a seriuous problem.
before starting the schedule setup, you have to consider the follwing:
1- the switchgear consists of circuit breakers, the bus, relays, earthing switches, (and might have disconnect switches) control panel and annunciator panel. The maintenance should include all these.
2- set the frequency...
The concern in DGA test results is not only the ppm of gases. The more important factor is the Trend of gases. Please let me know the results with ppm figures.
(:I