# 400 amp residential



## SWDweller (Dec 9, 2020)

I caution you to consider not bidding the project until the AHJ has taken a look and made their comments. What you see and what they see may be three different things. Then there is the utility issue. I have seen places where if someone wanted 400 amps they had to pay to upgrade the line and equipment. I bid a job with a 400 amp service with 2 200amp disconnects and the owner called me and said the utility was wanting 15K to provide the service. They redesigned for 200 amps.


----------



## blueheels2 (Apr 22, 2009)

Yeah my price would be based on the most expensive way to do it and a caveat that the AHJ and poco would have to approve all plans etc.


----------



## kb1jb1 (Nov 11, 2017)

Also check if you can use the 320 meter fora 400 amp service with 2 - 200 amp panels. In my area the 320 amp service is a 300 amp service. It is for 2 - 150 amp panels and no more. A 400 amp service with 2 - 200 amp panels requires a trans "S" type CT cabinet. I do not understand how some areas can sell a 320 meter as a 400 amp service. Or how the AHJ approves it.


----------



## blueheels2 (Apr 22, 2009)

kb1jb1 said:


> Also check if you can use the 320 meter fora 400 amp service with 2 - 200 amp panels. In my area the 320 amp service is a 300 amp service. It is for 2 - 150 amp panels and no more. A 400 amp service with 2 - 200 amp panels requires a trans "S" type CT cabinet. I do not understand how some areas can sell a 320 meter as a 400 amp service. Or how the AHJ approves it.



This scenario would be legal to use 4/0 SER as the feeders since the Ampacity is 150. Thats probably what needs to be done.



And this whole 400 amp service thing is weird anyway. As is 4/0 SER feeds a 200 amp panel and its allowed because its the entire load yet if I were to decide to build a t rue 400 amp service with ct cabinet the load of the existing panel would not change but the feeder would have to be ripped out and replaced with wire in a raceway to meet code. Yet not a dang thing changed.


----------

