Homes main panel is in a detached garage

[texie]

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

No, the 2/0 would still be fine as they never need to be larger than the service conductors and in your example I'm assuming that 2/0 service conductors already feed the meter.

 

[wwhitney]

No, the 2/0 would still be fine as they never need to be larger than the service conductors and in your example I'm assuming that 2/0 service conductors already feed the meter.

Ah, you're right. The problem I described would only arise if the detached garage is on a separate set of service conductors starting at the service point.

But I still think I'd prefer an interpretation that it's the designer's choice on whether to count the detached garage as "associated with an individual dwelling unit" or not. It would require being consistent--for a 200A service to a detached garage, with a 150A feeder to supply the house, you could use the 83% rule on the 200A service, or on the 150A feeder, but not both.

Cheers, Wayne

 

[mopowr steve]

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.

Mine is a sub feed lug setup.
200 amp main breaker in a 20 circuit panel with a plug in sub feed kit. (I believe it takes up 4 spaces)