I have been asked to temporarly hook up a piece of equipment. It is 480V 3 phase and has 90A fuses on its main disconnect. The majority of the load is the electric heaters. I have a 75 KVA auto transformer (600/480) that I am going to use. We have a 600V service. I was wondering if anyone has had any issues trying to power up a 75KVA transformer with 60A primary fuses on it. I want to disconnect the electric heaters on the piece of equipment for now since we are onlyy worried about testing the other connected loads such as motors and I/O. This would leave a very small connected load but I am worried that the inrush of the transformer would blow the 60 amp fuses. Should I be safe and fuse it at 80 amps as if it were fully loaded?
