# configuring 400 amp residential



## HackWork (Oct 2, 2009)

Hmmmm, good question. So there would be no way to shut off those conductors that come out of the meter and go to the detached garage? They wouldn't be a feeder, they would be service conductors. You would run 3 wires? That seems like it might not be compliant, but I am not sure.

My first instinct would be that you need to have both 200A disconnects grouped together. Then everything after that would be conventional.


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## dronai (Apr 11, 2011)

We in Calif would use a meter 400A with (2) 200A mains in the service


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## mikewillnot (Apr 2, 2013)

dronai said:


> We in Calif would use a meter 400A with (2) 200A mains in the service



I wouldn't mind quoting that in this case, but when I ask suppliers about it all I get is a blank stare.


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## mikewillnot (Apr 2, 2013)

HackWork said:


> My first instinct would be that you need to have both 200A disconnects grouped together. Then everything after that would be conventional.



And in such a case, I assume it would be 4-wire to each main panel.


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## HackWork (Oct 2, 2009)

mikewillnot said:


> And in such a case, I assume it would be 4-wire to each main panel.


Yes, the disconnects would be the main service where neutral is bonded to ground and the GEC’s land.

After that, four wires and separate neutrals and grounds to the house panel and garage panel.


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## Switched (Dec 23, 2012)

Not sure what your poco requirements are, but this is what we typically use here. Only issue is that you can't feed 2 200a panels off of it.

https://www.homedepot.com/p/Siemens...d-Center-Combination-MC3042B1400SDS/202819626

But I also found this: https://www.homedepot.com/p/Siemens...h-and-Ringless-Cover-MM0404L1400RLM/302878820


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## dronai (Apr 11, 2011)

Switched said:


> Not sure what your poco requirements are, but this is what we typically use here. *Only issue is that you can't feed 2 200a panels off of it*.


Yes you can. You can get 400A that comes with (2) 200A mains. Not at HD :smile:


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## Switched (Dec 23, 2012)

dronai said:


> Yes you can. You can get 400A that comes with (2) 200A mains. Not at HD :smile:


I wasn't sure.

The SQ D supply house is full of stupid people and their configuration tool kinda sucks.

Not to mention the panel I posted is $400 cheaper at HD then the last couple of times I got a SH quote.

Good to know on that unit.


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## HackWork (Oct 2, 2009)

You damn Californians with your meter/main panels that get set into the house against the NEC


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## Forge Boyz (Nov 7, 2014)

Midwest makes a nice unit with 2 200A mains in it. I used one last summer that also had a small 8 space loadcenter built into it. I think we paid around $800 for it.

Sent from my SM-G970U using Tapatalk


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## NoBot (Oct 12, 2019)

I just did this exact job here in PA. 
> 320 Amp Continuous - Meter Socket with 500 MCM line side lugs, Dual 4/0 load side lugs
> 4/0 SEU to 200 amp main breaker panel in house
>. 3" PVC schedule 40 underground conduit to detached garage with three - 4/0 XHHW Alum
> 3" schedule 80 at each end of exposed conduit
> 3" PVC 36" sweep elbows
> 3" at garage went under footer and directly to the 200 amp main breaker panel. This eliminated the need for LB's. I switched to 2" before entering the panel.
> two 1/2" x 8' ground rods at each panel with #6 CU
> #4 CU to copper water main at each panel.
> No Disconnects nor four wire sub panels required.
Power Company and Electrical Inspector approved all this before I started.


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## Dennis Alwon (May 9, 2009)

In the 2017 NEC the illustration is acceptable as they are service conductors going to different buildings.


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## mikewillnot (Apr 2, 2013)

Dennis Alwon said:


> In the 2017 NEC the illustration is acceptable as they are service conductors going to different buildings.



even though the disconnects are not grouped?
I had a conversation last year with a POCO engineer, a metering department guy, and the City electrical inspector, and they said that the disconnects on a *property* had to be grouped ... or maybe they said *premises.* I didn't think the assertion conformed to NEC, but ...


and BTW, the house service would require an outside disconnect as it's about 20' of cable inside the building.


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## macmikeman (Jan 23, 2007)

mikewillnot said:


> even though the disconnects are not grouped?
> I had a conversation last year with a POCO engineer, a metering department guy, and the City electrical inspector, and they said that the disconnects on a *property* had to be grouped ... or maybe they said *premises.* I didn't think the assertion conformed to NEC, but ...
> 
> 
> and BTW, the house service would require an outside disconnect as it's about 20' of cable inside the building.


NEC 230.2. The operative word is *Buildings* or other *Structures*, regarding number of services. Those are two different buildings in your drawing , each requiring it's own service.


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## Mulder (Sep 11, 2010)

mikewillnot said:


> I've only done a couple of these so far, and the last was so long ago I'm thinking the rules could well have changed. I believe this meets code, and I'd appreciate feedback. key points:
> 
> 
> Main house and (very) detached garage
> ...



The way you have it drawn is compliant. It is one service with two sets of service entrance conductors. Generally one service can only supply one set of service entrance conductors, but 230.40 Exc. No. 3 allows one set of service entrance conductors to the house and one set to an accessory building. 

Exception No. 3: A one-family dwelling unit and its accessory structures shall be permitted to have one set of service-entrance conductors run to each from a single service drop, set of overhead service conductors, set of underground service conductors, or service lateral.


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## kb1jb1 (Nov 11, 2017)

Time for a stupid question.

What is POCO? I assume a DISCO is a disconnect. I have a hard time with acronyms.


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## Mulder (Sep 11, 2010)

kb1jb1 said:


> Time for a stupid question.
> 
> What is POCO? I assume a DISCO is a disconnect. I have a hard time with acronyms.



POwer COmpany


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## kb1jb1 (Nov 11, 2017)

When buying equipment from Home Depot or any online supplier always check to make sure it meets the local utility company's requirements. Home Depot sells all over the country and just because it is sold does not mean you can use it. I know somebody who bought a 6 gang meter bank and did a beautiful job installing it. He saved over $1,000.00 buying it from Home Depot only to have the utility company reject it. Also some equipment might meet California's requirements but not New York's.

POCO = Power Company???


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## Southeast Power (Jan 18, 2009)

mikewillnot said:


> I've only done a couple of these so far, and the last was so long ago I'm thinking the rules could well have changed. I believe this meets code, and I'd appreciate feedback. key points:
> 
> 
> Main house and (very) detached garage
> ...


Check out page 52.
https://www.fpl.com/partner/pdf/electric-service-standards.pdf
FPL, doesn't allow us to cross over the underground incoming lateral. 
It might be different in your jursdiction.


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## Cow (Jan 16, 2008)

In your scenario, we typically use a Siemens 400 amp metermain, with (2) 200 amp breakers and usually 8 spaces for a little distribution, if needed. Then we use mobile home feeder cable to the garage.

This is the one we use, and it meets EUSERC standards:
https://www.amazon.com/Siemens-MC08...ens+400+amp+meter+combo&qid=1584104203&sr=8-5

Obviously, it is critical you verify power co requirements before going in a direction. There are LOTS of different types of metermains, the one I posted may not work in your area.


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## mikewillnot (Apr 2, 2013)

Switched said:


> Not sure what your poco requirements are, but this is what we typically use here. Only issue is that you can't feed 2 200a panels off of it.
> 
> https://www.homedepot.com/p/Siemens...d-Center-Combination-MC3042B1400SDS/202819626
> 
> But I also found this: https://www.homedepot.com/p/Siemens...h-and-Ringless-Cover-MM0404L1400RLM/302878820



Been digging around, found options, now I just have to get it POCO approved. Like pulling teeth, it is, to find a list or something.


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## TLelectricman (May 7, 2021)

NoBot said:


> I just did this exact job here in PA.
> 
> 
> > 320 Amp Continuous - Meter Socket with 500 MCM line side lugs, Dual 4/0 load side lugs
> ...


I Did a 400amp Service change, had 2-150amp main breaker inside garage behind old ct cabinet. I used the 2 lug 320 meter and when i started thinking about the panel changes inside I realized I would be over 6' on the 2nd panel so i changed the wire to 4 wire from meter to panel. In Fayetteville N.C. we have 2 power companies and at the supply house they ask which POCO determines which 320 meter base. I didnt finish yesterday in time for it to be inspected so no power returned. The meter base did not have enough lugs for my extra ground so reading this am I correct in leaving the 2/0 seu would have been ok due to this meter having a disconnect handle? I pullled those 2 new ser cables through a corner and that took forever plus the helper i sent to pick up the order i had ready at the supply house did'nt get the meter or panels and took his time getting to the job but i have an extra ground in meter that i hope the inspector will let me tape off or i may not get it inspected today due to having to work through those corners. I cannot believe I did not call and confirm with another electrician before changing that wire. I just dont do many 400 amp service changes so im used to the 6' rule on back to back 200 amp services with subpanel usually having to replace the old 3 wire with 4 wire. I did not do my homework on this one due to being overwhelmed with jobs and no secretary for a few months and having to work til late every night so i dont fall behind on all the paperwork. I doubt that anyone will see this before i leave this morning but if so please verify that i can use only three wires as long as my meter has a disconnect bar. Thanks in advance but ill be finding out soon enough if im going to have another long day or if i can cut the 2 panels in and call for inspection.


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