400 amp service

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Charlie Bob

Senior Member
Location
West Tennessee
I was asked by a future customer to give him a bid on his new house. He wants 2 200 amp panels. He's gonna have a detached garage, and he wants a panel in there too. i'm assuming a 100 amp one. i'm thinking installing outside disconnects, even tho it will cost a little bit more, since it'll make the job a lot easier to feed the detached garage in contrast to having a back to back service and then feed the garage from inside don't you think?. this is my first one with detached garage. . .
How do you all usually do it? i could have one panel back to back and another with a disconnect but i think it'll look silly.
Thanks.
 

kwired

Electron manager
Location
NE Nebraska
I was asked by a future customer to give him a bid on his new house. He wants 2 200 amp panels. He's gonna have a detached garage, and he wants a panel in there too. i'm assuming a 100 amp one. i'm thinking installing outside disconnects, even tho it will cost a little bit more, since it'll make the job a lot easier to feed the detached garage in contrast to having a back to back service and then feed the garage from inside don't you think?. this is my first one with detached garage. . .
How do you all usually do it? i could have one panel back to back and another with a disconnect but i think it'll look silly.
Thanks.

Why does he want 2 - 200 amp panels? Does he have any idea what kind of load he actually has or does he just think this would be a good thing to have? Kind of like putting a big 460 V-8 engine in a Honda Civic - just in case more power is needed:happyyes:.

You need to do load calculation and find out how much service capacity is needed. You can still install however many branch circuits you wish even if you end up with 100 circuits on a single 200 amp service.
 

kwired

Electron manager
Location
NE Nebraska
I would say if you had a disconnect outside as well as one (or more) inside you would have multiple service disconnecting means on that structure that are not grouped in same location.

It is however acceptable to have a junction box outside first building or if meter cabinet has enough room and POCO allows it will work also - connect whatever that building needs and continue on to second building - no disconnecting means makes the supply to second building still service conductors so no separate equipment grounding conductor is needed either.
 

hurk27

Senior Member
I was asked by a future customer to give him a bid on his new house. He wants 2 200 amp panels. He's gonna have a detached garage, and he wants a panel in there too. I'm assuming a 100 amp one. I'm thinking installing outside disconnects, even tho it will cost a little bit more, since it'll make the job a lot easier to feed the detached garage in contrast to having a back to back service and then feed the garage from inside don't you think?. this is my first one with detached garage. . .
How do you all usually do it? i could have one panel back to back and another with a disconnect but i think it'll look silly.
Thanks.

You have options that code will allow that will keep you to two disconnects on the house or no disconnects and just main breaker panels if the two 200 amp panels are located next to each other or one disconnect located next to one 200 amp main breaker panel, but it will depend upon calculated load as kwired said.

First you will need a 320 meter with triple load lugs the detached garage can run from the load side of the meter right back into the ground with just the two hots and neutral over to the garage then hit a main breaker panel in the garage which you just treat like a service which code requires us to do anyways except the separating of grounds and neutral as you would if you ran a feeder and had a separate EGC which you would not need in the above since these are service conductors.

And you don't need a disconnect at the house because you have not entered a building yet (which you do at the garage) so that not only eliminates the EGC it also eliminates an extra disconnect only requiring one at the garage which can be a main breaker panel.

Second you need to keep 230.72 in mind for the disconnecting means anytime you do a split service on a single building, so because of this you can either have two 200 amp disconnects out side and two main lug only panels anywhere inside, or two main breaker panels just inside but they have to be grouped, or one main breaker panel inside and a disconnect next to it so that one panel can be located elsewhere closer to loads, so you have options to chose from and some of these can be money saving for you or the owner.

The detached garage trick is allowed by two things, the exception #3 in 230.40 and the fact the wording of 230.70 only requires a disconnect for conductors "in a building" and running from the load side of the meter base into the ground is not "in a building" and is the whole reason for the exception #3 to 230.40 also a meter is just a wide place in the service entrance conductors and is not a disconnect so the wires from the load side are still service entrance conductors and are treated as such and because of this the neutral is the EGC so the main breaker panel in the detached garage is service equipment and bonding (main bonding jumper) is required just like at the house.

not many know or understand this allowance but it is right there in the NEC as I have pointed out.

I hope this gives you some better ideas to allow some savings for this service.
 

ActionDave

Chief Moderator
Staff member
Location
Durango, CO, 10 h 20 min from the winged horses.
Occupation
Licensed Electrician
I agree with Kwired. Is a 400A service really needed or just wanted.
If it is not needed but still wanted I would make every effort to give the HO everything he asks for.

As far as how to arrange the equipment, that is dependant on the site. Sometimes it is easier to mount the meter on the garage and go on to the house. One monster house I worked on we built a rack for the service equipment away from the house so it could be hidden by some bushes.
 

Charlie Bob

Senior Member
Location
West Tennessee
You have options that code will allow that will keep you to two disconnects on the house or no disconnects and just main breaker panels if the two 200 amp panels are located next to each other or one disconnect located next to one 200 amp main breaker panel, but it will depend upon calculated load as kwired said.

First you will need a 320 meter with triple load lugs the detached garage can run from the load side of the meter right back into the ground with just the two hots and neutral over to the garage then hit a main breaker panel in the garage which you just treat like a service which code requires us to do anyways except the separating of grounds and neutral as you would if you ran a feeder and had a separate EGC which you would not need in the above since these are service conductors.

And you don't need a disconnect at the house because you have not entered a building yet (which you do at the garage) so that not only eliminates the EGC it also eliminates an extra disconnect only requiring one at the garage which can be a main breaker panel.

Second you need to keep 230.72 in mind for the disconnecting means anytime you do a split service on a single building, so because of this you can either have two 200 amp disconnects out side and two main lug only panels anywhere inside, or two main breaker panels just inside but they have to be grouped, or one main breaker panel inside and a disconnect next to it so that one panel can be located elsewhere closer to loads, so you have options to chose from and some of these can be money saving for you or the owner.

The detached garage trick is allowed by two things, the exception #3 in 230.40 and the fact the wording of 230.70 only requires a disconnect for conductors "in a building" and running from the load side of the meter base into the ground is not "in a building" and is the whole reason for the exception #3 to 230.40 also a meter is just a wide place in the service entrance conductors and is not a disconnect so the wires from the load side are still service entrance conductors and are treated as such and because of this the neutral is the EGC so the main breaker panel in the detached garage is service equipment and bonding (main bonding jumper) is required just like at the house.

not many know or understand this allowance but it is right there in the NEC as I have pointed out.

I hope this gives you some better ideas to allow some savings for this service.

Yeah thanks , that helps a lot.
 

Charlie Bob

Senior Member
Location
West Tennessee
Why does he want 2 - 200 amp panels? Does he have any idea what kind of load he actually has or does he just think this would be a good thing to have? Kind of like putting a big 460 V-8 engine in a Honda Civic - just in case more power is needed:happyyes:.

You need to do load calculation and find out how much service capacity is needed. You can still install however many branch circuits you wish even if you end up with 100 circuits on a single 200 amp service.

I told him that. . he insisted, he said he built another house before and that what he used. i will approach him with some numbers tho, that may change his mind. he even said he might go with gas for heat and water heaters. . .
 

kwired

Electron manager
Location
NE Nebraska
I agree with Kwired. Is a 400A service really needed or just wanted.
If it is not needed but still wanted I would make every effort to give the HO everything he asks for.

As far as how to arrange the equipment, that is dependant on the site. Sometimes it is easier to mount the meter on the garage and go on to the house. One monster house I worked on we built a rack for the service equipment away from the house so it could be hidden by some bushes.


Unless you have electric heat or a monster of a house or some other big load 200 amps is usually plenty for a dwelling. You can still install 2 panels to have lots of circuit spaces and supply them with a common 200 amp feeder. To supply them with 400 amps of conductor and larger switch and meter socket starts to get expensive - then they will be complaining about the cost. :slaphead: We need an emoticon of a contractor wrapping his hands around a customers neck:D
 

ceb58

Senior Member
Location
Raeford, NC
If the customer is set on having 2-200 amp panels I would set a 400 amp meter/combo with an 8 space buss. Feed the house with the 2 200 amp breakers and put in a 100 amp on the buss for the garage. This will still give you 6 spaces you can feed the A/C, well pump or what ever.
 

Charlie Bob

Senior Member
Location
West Tennessee
If the customer is set on having 2-200 amp panels I would set a 400 amp meter/combo with an 8 space buss. Feed the house with the 2 200 amp breakers and put in a 100 amp on the buss for the garage. This will still give you 6 spaces you can feed the A/C, well pump or what ever.

Thanks. . . i talked to inspector today he said he really prefer to feed the garage from the triple luged meter base. two sets for the two 200 amp panel in the house and one for the garage. He prefers not having a disconnect for the garage by the meter since people might think it's for the house.
 

GearMan

Member
Location
WI
Thanks. . . i talked to inspector today he said he really prefer to feed the garage from the triple luged meter base. two sets for the two 200 amp panel in the house and one for the garage. He prefers not having a disconnect for the garage by the meter since people might think it's for the house.

ceb58 has the best thought. Not sure why the inspector has to prefer. The 320 socket / 2-200A breakers paralleled with an extra 8-cct's is a much better option for the owner. This is all we use in our area...Xcel Energy. Siemens, Milbank & Midwest all supply in our area.
 

Charlie Bob

Senior Member
Location
West Tennessee
ceb58 has the best thought. Not sure why the inspector has to prefer. The 320 socket / 2-200A breakers paralleled with an extra 8-cct's is a much better option for the owner. This is all we use in our area...Xcel Energy. Siemens, Milbank & Midwest all supply in our area.

Thanks i'll consider that, ther only thing is that then i'll have to provide that to customer,. . .here we get the triple luged 400 amp meter base free with the inpections fee. . .how much one like that you r talking about cost?
 

GearMan

Member
Location
WI
Thanks i'll consider that, ther only thing is that then i'll have to provide that to customer,. . .here we get the triple luged 400 amp meter base free with the inpections fee. . .how much one like that you r talking about cost?

Nothing is free...I won't go in to the politics :happyno:I'd sell it to the owner, they will be glad you did next time they want to feed an out building or another small circuit. Now you are the hero.
 

kwired

Electron manager
Location
NE Nebraska
Nothing is free...I won't go in to the politics :happyno:I'd sell it to the owner, they will be glad you did next time they want to feed an out building or another small circuit. Now you are the hero.

An I-line panel would work great also. They are not free either:D
 

ceb58

Senior Member
Location
Raeford, NC
Thanks. . . i talked to inspector today he said he really prefer to feed the garage from the triple luged meter base. two sets for the two 200 amp panel in the house and one for the garage. He prefers not having a disconnect for the garage by the meter since people might think it's for the house.

:slaphead:Do what???? What dose he think a label maker or sharpie is for? Besides if there were an emergency situation in the house would it make that big of a difference if the garage was shut off also?

Thanks i'll consider that, ther only thing is that then i'll have to provide that to customer,. . .here we get the triple luged 400 amp meter base free with the inpections fee. . .how much one like that you r talking about cost?

The last one I bought was a C-H. They come with 1-200 amp breaker installed, you have to buy the other one. I think it was around $800.00 for it and the breaker. It will well pay for its self if you need to come back later to pick up power for something else.
 

GearMan

Member
Location
WI
:slaphead:Do what???? What dose he think a label maker or sharpie is for? Besides if there were an emergency situation in the house would it make that big of a difference if the garage was shut off also?



The last one I bought was a C-H. They come with 1-200 amp breaker installed, you have to buy the other one. I think it was around $800.00 for it and the breaker. It will well pay for its self if you need to come back later to pick up power for something else.

Yep. Simple product, the only way to go. Here is a link to the one we use, same ballpark price.
http://www.sea.siemens.com/us/inter...ter Cominations and Mains/MC0816B1400RLTM.pdf
 

stickboy1375

Senior Member
Location
Litchfield, CT
If the customer is set on having 2-200 amp panels I would set a 400 amp meter/combo with an 8 space buss. Feed the house with the 2 200 amp breakers and put in a 100 amp on the buss for the garage. This will still give you 6 spaces you can feed the A/C, well pump or what ever.

This would only be code compliant if the meter/combo was installed at the house.
 

stickboy1375

Senior Member
Location
Litchfield, CT
Thanks. . . i talked to inspector today he said he really prefer to feed the garage from the triple luged meter base. two sets for the two 200 amp panel in the house and one for the garage. He prefers not having a disconnect for the garage by the meter since people might think it's for the house.

The garage is detached and would still require a disconnect at that location. And who cares what the inspector prefers? Is he paying for the installation?
 
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