Discussion Starter · #1 ·
So I know I might catch some **** on this one since I mostly stick to residential work and some smaller commercial work. So I've been doing some upgrades and installing lighting for a guy who owns some office buildings, pretty easy ****. So I get a call from him that they are having some problems at another one of his buildings. Well come to find out they keep losing power to the entire building of a 20k sq. ft. medical center. They have a 1k amp 240/480 with a GFCI Main. Anyways I discovered the problem and it was a faulty sterilizer in one of the operating rooms. Sorry for the setup but now to my question. I don't do this large scale of work but my understanding from research is that 480 panels must have a GFCI main. Why is the main GFCI protected and nothing else? Does this mean that if there is a ground fault anywhere in the building (besides wet areas) that the entire building will loose power?? Is this normal in these applications? Thanks for any knowledge in this area.