400 amp service

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jzadroga

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Is it permissible to have two 200 amp panels with main breakers each fed by their own set of feeders from one 400 amp meter? The panels may or may not be located together. Also what size conductors would you use if this meets code? This installation is residential.

I always install 400 amp services using a 400 amp meter socket with parallel 4/0 copper feeders to a 400 amp disconnect which then feeds out to the panels. I have seen other contractors use the method that I question. I ask because their method is obviously cheaper and in a bidding situation it may make the difference.
 
Re: 400 amp service

Yes you can, I did this myself on my own house. However, the panels must be "grouped" which usually means side-by-side and on the same side of the wall (inside or outside but not both).

Because these are Service Entrance conductors (not feeders), you can use 2/0 copper or 4/0 Al to each panel per 310.15(B)(6). You also have to limit the length of them inside the structure per local rules (typically 5 to 15 feet).

If you use a single 400A disconnect (or two 200A disconnects grouped together), then the 200A panels can be placed throughout the structure. Because of the cost of anything 400A, you can save a lot by eliminating that big disconnect or panel. Residential 200A MCB panels are dirt cheap.
 
Re: 400 amp service

We're doing one today. We've done (4) others this month.
400a socket, (2) 200a CH panels, (2) whips of 4/0al SEU.
 
Re: 400 amp service

I thought the disconnects have to be grouped, not the panels. Unless you are saying the panels must be grouped because the protection for the panels is a main. I just did a similar type installation, and the disconnects were the grouped together, on the same wall with one 400A metered service.

Would you consider using disconnects instead of main breakers, so that you can put the panel where you want it?? :)

[ September 22, 2004, 03:28 PM: Message edited by: lady sparks lover ]
 
Re: 400 amp service

sometimes to get this done we must put 2 disconects on the outside and locate the main lug panels where the owner wants them.Only the disconnects must be grouped not the panels.
 
Re: 400 amp service

If there is no OCP between the meter socket and panels and the panels have mains, the panels contain the disconnects(mains) and must be grouped.
 
Re: 400 amp service

if you have 2 back to backed 200 amp panels on a 320/400 rated meter or 1 200 mbr panel and a 200 amp disc. no difference the 1st panel is your main panel after that it is a sub panel if 200 amp so be it 4 wire to the sub panel even if 200 it`s ok.Yes they must be grouped together as disconnects after that as long as in allowed areas then all is good.
 
Re: 400 amp service

Square "D" makes a 400 amp meter main now that uses a 320A meter socket and has twin 200 amp main breakers on the load side for connecting sub-panels. Very similar to the 200 amp meter/mains, just has 2 breakers instead of one. Cost is in the ballpark of $800.00 I think. We have used them on several large (8000'+) homes. Very quick to install so cost effective as well.
 
Re: 400 amp service

Take the cost of a 320/400 meter base and 2 200 mbr panels.Less than 1/2 of $800.00.Lets say the panels are within the house.The meter base and disconnects and MLO panels id still less than that figure.Labor is cheaper than the material in this senario.
 
Re: 400 amp service

I have used the Midwest 320 MM and the Siemens 320 MM. They both have a 320 meter socket and (2) 200A mains. The costs are within $50.00 of each other at around $500.00. If I use a 320A MB, (2) 200A W/P disconnects and nipple them together I have $185.00 in the MB and $275.00 in the (2) disconnects for a total of $460.00 plus nipples, locknuts, bushings. I can install the MM in about 2 hours less than building the MB and disconnect set-up and mounting it. Cost-wise I think it's about even. The MM makes for a neater looking job, in my opinion.
 
Re: 400 amp service

But the least expensive of all is a 320A meter socket ($150) and two 200A MCB panels inside the house right behind the meter($200). No more panels are required and total cost is $350.

I really don't like main breakers on the outside of a house -- any bozo can come and turn them off. If you lock them, that defeats the purpose of having them outside. I'd only use outside disconnects if local codes mandated it.
 
Re: 400 amp service

Where we have been doing alot of our work in this area the poco supplies the meter base so that cost is $0.00(providing the load calc shows 400 is required)That leaves us with disconnect or panel to factor in,unless it`s a split service back to back MBKR panels are about $85.00 @ to buy as we buy in bulk.As far as from the trans. to the meter unless it is a commercial/insudtrial 3 phase job not an issue.The poco does that too ;)
 
Re: 400 amp service

Back to back meterbase to MB panels is the lowest cost way to go if you can. PoCo stopped supplying MB here about 7 years ago. I can't buy a copper bus 200A 40 ct MB loadcenter here for less than $110.00. The same loadcenter in MLO runs around $85.00. I too buy in quantity.
 
Re: 400 amp service

We dont even consider buying MLO panels since to buy a few panels MLO the cost effectivness is out the window.By bulk I mean a minimum of 2.500 a year probably closer to 3.000 this year.So to those wondering yes if the service is a split we still use th MBKR panel rather than order a MLO panel for one /few jobs.It`s not worth the paperwork to order a MLO panel for a few jobs.
 
Re: 400 amp service

$250,000.00 a year just in MB loadcenters!!! You'd think the manufacturer would cut you the same margin on MLOs too. Siemens bases my price(margin) on total dollars spent with them per year. So does GE. That runs me about $80,000.00 per year but it includes switch gear, transformers, breakers, loadcenters, tubs, interiors, starters, contactors, fused and non-fused disconnects. If your company works 5 days a week 52 weeks a year that means you're installing over 11-1/2 loadcenters a day on average. You must work for a huge contractor.
 
Re: 400 amp service

I just bought a panel for a friend's house, 400 amp "all-in-one", with (2) - 200 amp mains. One main fed the 40 circuit distribution within and one main is for a sub. $700.00.
 
Re: 400 amp service

Amptech,over 140 trucks on the road daily.Have both hourly and flat raters on the payroll.We did 2,500 homes last year and it looks like around 3,000 this year.One of the sub division I oversee is finishing up over 800 homes in 2 years,getting ready to start 1,100 homes in a 3 year project next month.That`s just one of many projects we have and are getting.
 
Re: 400 amp service

FYI: A Milbank 400 amp meter socket combo with 2-200 amp breakers costs $1000 here, since our main utlity requires all residential metering to have a bypass.
 
Re: 400 amp service

Peter d, That's outragous! We can't get Milbank here at all anymore. Siemens or Midwest and like I said earlier, around $500.00 each. After reading some of these posts, it looks like loadcenter prices from the same manufacturer are all over the place. A set-up that may be a good value in one part of the country might be too costly in another.
 
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