A customer of mine has two transformers adjacent to their building for 2400 2ph 3 wire
to 240v 2 ph 5 wire conversion. Inside the building the oil switch was hit by lightning which fried one of the coils for the fault trip. Anyway we are going to repair it, which involves interupting power from the street. Question is, these xfmrs are probably 50 years old easy. We are going to rebug the connections, and retape, since the power will be off anyway. Should the oil be changed? Will changing the oil help? or will it possibly alter the performance and possibly cause rapid failure due to the fact it has never been changed? I am comparing it to my experiences with say automatic transmissions. The fluid should be changed every 15000 or so. But if never changed and the vehicle has very high miles, changing the fluid could cause failure to the tranny.
Can someone shed some light and experience please?
