Hi,I am an electrician that has done mostly residential work up to 200A service.I have a job that will require 400Amp service.Seeing I have never done one I am seeking any advise that you could give me.I have read that most of the time 2 200A panels are used.This project is a garage and I would like to use just 1 main panel.Is this impractical? Just looking for some guidance. Thanks in advance.
I use either a 320A metermain with (2)200A breakers installed to feed (2)200A 40ct ML panels or if they can be back to back with a 320A meterbase I use (2) 200A 40ct MB panels. I am currently upgrading a 320A service at a house to an 800A due to a 6500 sq.ft. addition. The PoCo is hitting my CT cabinet at the addition where it will feed a 800A ML panelboard with (1)400A CB to feed the old service and (2) 200A CBs to feed (2) 200A 42ct ML panels in the new addition. Houses around here keep getting bigger and stupider.
I always wonder how much of that 400a actually gets used. What are these people's electric bills? Average 60a 24/7 is over $1000 a month here.
Generally speaking, in many places 400A service is the next step up if the load calc exceeds 200A. And, of course, the load calc is interested in making sure that the probable sustained peaks are covered; it's not about the average draw. So one might need a 400A service when the current draw averaged over the course of a month is only a few dozen amps or less.
So it looks like I need a 1/O GEC for 400A service based on 600 kcml conductors. Do you normally parallel them with smaller conductors? Any help on the conductor size please. Also do they make a rebar clamp for the 1.5" rebar for the 1/O conductor size?
Reno- I believe that would be true if the 320a. were a continious load. He stated that this was a residential installation and residential is not continious. He could do the calc and come up with 400a. and if the equipment were rated for 400a. he's good to go.