Dustyswartz
Member
- Location
- North dakota
- Occupation
- Electrician
Is there any code that says a homes main distribution panel has to be attached to the home itself? Can a home have its main distribution panel in a detached garage?
Homes main panel is in a detached garage
- Thread starter Dustyswartz
- Start date
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mopowr steve
Senior Member
- Location
- NW Ohio
- Occupation
- Electrical contractor
Sure, my place is just like this.
Just remember that the panel in the house will be a feeder so it will need 4 wire.
Just remember that the panel in the house will be a feeder so it will need 4 wire.
Dustyswartz
Member
- Location
- North dakota
- Occupation
- Electrician
2 hots a neutral and a ground?
Dustyswartz
Member
- Location
- North dakota
- Occupation
- Electrician
So is your sub panel fed from a 2 pole 100 amp breaker or something? To me it just seems like an expensive unnecessary additional point of possible failure if that makes sense.
- Location
- New Jersey
- Occupation
- Journeyman Electrician
The house has it's own panel?
Dustyswartz
Member
- Location
- North dakota
- Occupation
- Electrician
There is no house yet. So I'm bringing power from the pole to the meter which will be on the garage. Then into the 200 amp panel in the garage which will eventually feed a house that will be detached.
- Location
- New Jersey
- Occupation
- Journeyman Electrician
Your setup is fine. As mentioned you'll need a 4 wire feeder to the house panel and a disconnecting means at the house. Also needs its own GES.
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
I once worked on a house with the panel in a detached garage, and standard NM cables in two 2" PVC conduits buried in the ground and emerging in the house's crawl space. I have no idea how it passed.
- Location
- Bremerton, Washington
- Occupation
- Master Electrician
You won’t be able use use the reduced size of 83% on feeders from garage to house. IE, for 200 amps you will need 250 Al.
assuming the size of the service entrance conductors are based on 310.12, would you apply 310.12 C ?
- Location
- Bremerton, Washington
- Occupation
- Master Electrician
There is no 310.12 in my 2017. 310.15 B 7 states it has to be the entire load. But in reading this again, its a feeder so the reduced ampacity may be allowed. Lets see what others say
wwhitney
Senior Member
- Location
- Berkeley, CA
- Occupation
- Retired
The only way I could see that you wouldn't be able to use the 83% factor on the feeder from the garage to the house is if (a) you decide the garage load is associated with the dwelling unit (not 100% clear to me either way) and (b) the feeder rating is smaller than the service rating.
Cheers, Wayne
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
Remember that feeder conductors need not be larger than the service conductors.
jaggedben
Senior Member
- Location
- Northern California
- Occupation
- Solar and Energy Storage Installer
310.12(C) in 2020 NEC = 310.15(B)(7)(3) in 2017
83% rule aside, why would 4/0 aluminum at 75C terminations with a 190 ampacity and next size up rule to 200 amp not work? Assuming calculated load was 190 amps or less and no other conditions of use.
- Location
- New Jersey
- Occupation
- Journeyman Electrician
Actually it's 180 amps but you're correct, the next size up rule would allow a 200 amp OCPD if the load were 180 amps or less.
texie
Senior Member
- Location
- Fort Collins, Colorado
- Occupation
- Electrician, Contractor, Inspector
Good point. The OP could just use a 200 amp feed thru panel and use conductors the same size as the service reduced size service conductors. But I was thinking that the OP was going to use , say, a 150 feeder to the house which would not qualify for the 83% rule.
wwhitney
Senior Member
- Location
- Berkeley, CA
- Occupation
- Retired
It would if you consider the detached garage not to be a load "associated with an individual dwelling unit." The feeder to the house would still be supplying the "entire load" of the dwelling unit in that case.
If you say the detached garage is definitely a load "associated with an individual dwelling unit," let me flip that question around for purposes of discussion. Supposed you have a house with no garage and a 200A service supplied by 2/0 Cu service entrance conductors. And the owner decides to build a detached garage, and supply it with a separate set of service entrance conductors (after the meter) run to a service disconnect on the garage. Now you're saying that the service disconnect on the house has to downsized to 175A, or the house SECs have to be upsized to 3/0 Cu, because the house service doesn't supply the "entire load".
I think that leads me to suggest that whether a detached garage is a load "associated with an individual dwelling unit" should be at the discretion of the electrical designer and could go either way.
Cheers, Wayne
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