Sizing overhead service entrance conductors

[Dennis Alwon]

I am afraid to post on this topic as everyone will realize just how dumb I am but here goes....

not dumb but perhaps ignorant of the facts-- very different..

First a common denominator here is for a 200 amp panel use 3/0 and for 400 use 400 mcm. Since the OP says it is a residential single service why not 2/0 and for the 200 amp according to 310.15(b)(6) 2008 edition.

400 kcm is fine for 400 amps since it serves the entire load of the unit however if you have 2- 200 amp panels then neither panel serves the entire load so the ampacity must be based on 310.15 not (B)(7) resi table. That means 3/0 must be used

Second for 400 residential services I use the 320m meter fittings. I would think it would be much less expensive.

If I am all wet on this I would like to know it. Everyone can go ahead and laugh now.

Bob

Typically a 400 amp meter base is rated 320 continuous load and 400 amps non continuous so in essence the 320 amp base is called a 400 amp meter base.

 

[JoeStillman]

400A is an awful big house.

 

[Dennis Alwon]

400A is an awful big house.

Just finished one with 600amp and starting another with 600 amps. 12,000 sq.ft

 

[kwired]

400A is an awful big house.

Not necessarily. I did a fairly large house once that had 65kW of electric heat, but had it been gas heat service capacity could have been cut down quite a bit, so it all depends on what load is connected.

 

[JoeStillman]

When I see people living in houses like that I know I'm in the wrong business.:happyyes:

 

[kwired]

When I see people living in houses like that I know I'm in the wrong business.:happyyes:

Well that guy have to go to med school for several years to even get started on the path he is on now.