amp Service vs Breakers installed

[Paul@Klapperichtool.com]

I have a machine shop in an industrial building with 400Amps of service at 480 volts. Currently, there are a bit more than 400 amps worth of breakers installed in the panel. What is the code regarding this matter?

I want to install 3 or 4 more machines to run off of a 100 Amp 480V Sub-Panel, but I don't know the code or recommodation for sizing breakers/fuses. Can I go 30% over or something like that?

Also, should I always fuse at the machine nameplate rating, or something less?

I suspect that this is probably not an easy thing to answer for certain. I am trying to get a feel for whether or not I need to hire someone to evaluate the situation, or if I can do something without causing a potential problem.

Paul Klapperich

 

[charlie b]

There is too much we would have to tell you, in order to give you enough of an understanding to allow you to make an intelligent decision. You are going to have to consult with an electrician or an electrical engineer.

I am closing this thread, as is required by forum rules. We cannot assist a person who is not a member of the electrical industry in the design or installation of electrical equipment.