Multiple services feeding the same building

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grizwald

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This is a residential building; there is a main house and a separate garage with an 2nd unit above. The second unit is to be on its own meter, while the garage below it is on the house meter. I'm having difficulty finding a code section that clearly states whether this is legal? There are a few other issues like a heat pump located in the garage that supplies the 2nd unit...Homeworks lighting system in all buildings, that is all connected and controlled from all three areas. Am I over thinking this or does this bring up a red flag? Thanks for your help.
 
iwire said:
The number of meters has nothing to do with the number of services.
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ok then, can I have feeders from two different meters in the same gutter; the gutter is on the garage/2nd unit...+/- 300' away from the actual service location. I have not come across this situation before...just trying to address any issues before they become an issue :)
 
There are definitely red flags. Generally speaking each structure (the house bring one structure, the detached garage with apt above being a 2nd) can have only one service or feeder supply. See 225.30 & 230.2 for exceptions.
 
augie47 said:
There are definitely red flags. Generally speaking each structure (the house bring one structure, the detached garage with apt above being a 2nd) can have only one service or feeder supply. See 225.30 & 230.2 for exceptions.
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That's the way I was interpreting things but like I said, I haven't been in this situation before. 225.30 seems to apply here; there is only one service but, there will be three feeders. One to the house, one to the garage, and one to the 2nd unit above the garage. That can't be right? There is only two meters...

My understanding is that, the garage and 2nd unit will need to be on the same feeder/meter. My boss is not going to be happy :happysad:
 
grizwald said:
That's the way I was interpreting things but like I said, I haven't been in this situation before. 225.30 seems to apply here; there is only one service but, there will be three feeders. One to the house, one to the garage, and one to the 2nd unit above the garage. That can't be right? There is only two meters...

My understanding is that, the garage and 2nd unit will need to be on the same feeder/meter. My boss is not going to be happy :happysad:
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I think you can have 2 meters on the garage. one for the apartment and one for the garage. that would be a single feeder to that structure. The house would have its own meter.

I don't see any legal way to separate them otherwise short of some special dispensation from the AHJ.

ETA: Having said all that, you might be able to get the building department to determine that the apartment is a separate structure since it will probably need a firewall between it and the garage anyway.
 
petersonra said:
I think you can have 2 meters on the garage. one for the apartment and one for the garage. that would be a single feeder to that structure. The house would have its own meter.

I don't see any legal way to separate them otherwise short of some special dispensation from the AHJ.

ETA: Having said all that, you might be able to get the building department to determine that the apartment is a separate structure since it will probably need a firewall between it and the garage anyway.
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That seems like a good solution :thumbsup: As far as the 2nd unit being a separate structure...I'll let the General Contractor argue that, seems like a stretch to me. Thanks for your input.
 
grizwald said:
That seems like a good solution :thumbsup: As far as the 2nd unit being a separate structure...I'll let the General Contractor argue that, seems like a stretch to me. Thanks for your input.
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think about how townhomes are made. they are considered separate structures even though they share a common wall.
 
grizwald said:
This is a residential building; there is a main house and a separate garage with an 2nd unit above. The second unit is to be on its own meter, while the garage below it is on the house meter. I'm having difficulty finding a code section that clearly states whether this is legal? There are a few other issues like a heat pump located in the garage that supplies the 2nd unit...Homeworks lighting system in all buildings, that is all connected and controlled from all three areas. Am I over thinking this or does this bring up a red flag? Thanks for your help.
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Since you indicated that the garage dwelling unit will be metered from the garage than the utility must have approved a meter location at the garage.

You would simplify things if you put both meters at the garage, If the service drop or lateral went to the garage and from that location a feeder lateral was run to the house.

Use 230.4 exception 2 and group the three service disconnects at the garage two meter(s) location.
 
augie47 said:
There are definitely red flags. Generally speaking each structure (the house bring one structure, the detached garage with apt above being a 2nd) can have only one service or feeder supply. See 225.30 & 230.2 for exceptions.
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I'm not so certain anything prohibits one service and one feeder to supply the building though.

230.2 simply says a building shall be supplied by only one service. Doesn't mention additional feeders or branch circuit supplies being prohibited

225.30 says it shall only be supplied by one feeder or branch circuit. Doesn't mention service supply from services.

I find nothing stating you can't have a feeder and a service to an individual building.

It is less complicated if you have different voltage, phases, frequency, or supply source like a generator, PV equipment etc. but in OP's case both buildings are supplied by same voltage/frequency/number of phases.. and likely even come from same transformer.

If doing both I think you would want both disconnects in the same location, but that may not even be required - but a directory telling where other disconnects are should be required.
 
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