Accessory structure- service

[dog]

What is the minimum amp for service to garage- feed from main structure to garage with a ground rod for that service? GFI receptacles with (2) lights.The feeder underground UF cable from main service to accessory structure for service equipment in accessory structure?

 

[tom baker]

Re: Accessory structure- service

The minimum ampacity is determined by the load. If other than a single branch circuit then you will need a disconnecting means. See Art 100 definition of branch circuit and feeder. You may also need a grounding electrode system. If a feeder you'll want to use a 4 wire set up with the neutral not grounded at the garage.

But the minimum minimum would be a 15 amp, 120V branch circuit, with 14 AWG UF.

I would run 1" PVC conduit with 4 8 AWG THHN, set a 6 ckt loadcenter with a 2 pole 40 amp main. the extra cost is minimal, esp as you'll have the ditch open.

 

[iwire]

Re: Accessory structure- service

Tom wouldn't he have to follow the rules of 225.39?

Wouldn't the six circuit load center you mention require a 60 amp feed?

2002 NEC

225.39 Rating of Disconnect.
The feeder or branch-circuit disconnecting means shall have a rating of not less than the load to be carried, determined in accordance with Article 220. In no case shall the rating be lower than specified in 225.39(A), (B), (C), or (D).
(A) One-Circuit Installation. For installations to supply only limited loads of a single branch circuit, the branch circuit disconnecting means shall have a rating of not less than 15 amperes.
(B) Two-Circuit Installations. For installations consisting of not more than two 2-wire branch circuits, the feeder or branch-circuit disconnecting means shall have a rating of not less than 30 amperes.
(C) One-Family Dwelling. For a one-family dwelling, the feeder disconnecting means shall have a rating of not less than 100 amperes, 3-wire.
(D) All Others. For all other installations, the feeder or branch-circuit disconnecting means shall have a rating of not less than 60 amperes.

Bob

[ July 07, 2003, 06:25 PM: Message edited by: iwire ]

 

[pierre]

Re: Accessory structure- service

Bob and Tom
Take a look at 225.30
Specifically the last sentence, "For the purpose of this section, a multiwire branch circuit shall be considered a SINGLE CIRCUIT.
In Art 100 a multiwire branch circuit is considered a single circuit. 210.4 Considers it multiple circuits.
A single (muliwire branch circuit) circuit to this garage would seem to cover the load and therefore it will not have to follow all of the other requirements.I believe this would fall under 225.39(A).
So a 12/3 UF cable to the garage with 2 - 2o amp breakers would be all he needs for this garage.

Pierre

 

[iwire]

Re: Accessory structure- service

I agree 100% Pierre, if all he wants is a branch circuit.

I was thinking a feeder as the opening post said

By Dog

The feeder underground UF cable from main service to accessory structure for service equipment in accessory structure

Bob

 

[tom baker]

Re: Accessory structure- service

Pierrre, you are right on, I didn't mention this, I didn't want to complicate the issue. And it should be a 60 amp feeder.

 

[jimb]

Re: Accessory structure- service

Bob,

225.39 only refers to the minimum rating of the disconnect not the actual rating of the feeder. It could be permissable to supply a building with a 30A feeder as long as the disconnect at the detatched building is rated for 60A or better.

Jim

[ July 08, 2003, 11:09 PM: Message edited by: jimb ]

 

[iwire]

Re: Accessory structure- service



[ July 10, 2003, 04:11 AM: Message edited by: iwire ]