Ok, Jason said what I was gonna say,except he makes more sense than me. Balloning cylinders, friction, more heat, blowby?
Large industrial/institutional electrial equipment generally relies on overdesign to avoid excessive temperature.Sustained temperatures over 90C causes excessive vottage losses and increased resistance . Then the switch gear vaporizes,and out go the lights, lots of overtime.Large transformers are often oil cooled.After the power was shut down, we used stick our bare arms in the PCB oil to service the electrial connections.Don't worry, the managers said, those PCB's are safe.Then go out side to have a smoke with oily hands.Ah, the good old days.
