ECN Forum Forums Code Related Discussion NEC & other Code issues detached structure disconnect and 3 way switching

I don’t have access to an ‘08 code book anymore, but in the 2011, the way the new last sentence in 225.30 is worded, it seems to allow this, "only one feeder or branch circuit that originates at the additional building or other structure to supply power back to the original building or structure unless permitted in 225.30[A] Special Conditions."
So if I’m reading this correctly, it would seem that the 3-way would be allowed to be supplied from a branch circuit originating in the garage, under the 2011 NEC anyway.

Kjay:

There may be some severe debate over the gramatics of this...." "only one feeder or branch circuit that originates at the additional building or other structure to supply power back to the original building or structure unless permitted in 225.30[A] Special Conditions."


"Only one feeder or branch circuit...." 'only one....or...' . Reading the OPs comments, there seems to be a 'feeder' and a 'branch circuit' involved in his scenario. Now, the 'branch circuit' is a 3-way switch loop, with the 'load' at the outbuilding. Assume the 3-way circuitry contains the neutral for the 'load' (hopefully, as this was not mentioned), so the switch loop can be defined loosely as a branch circuit. That may be construed by some as there is both a feeder and branch circuit, and be an issue.

George, what say you of the above??

I think the wording in the '11 code says what I was trying to say and I hadn't read it until after I posted my previous post.

You can have a sub panel in a detached structure and have a circuit coming out of this sub panel supplying a circuit running back to the main building. Works for a 3 way system between the two buildings.

One More Thing-
I know I've allowed a three way system between the detached building and the main building with the circuit originating in the garage and never worried about it. The '11 code now clearly addresses it. The problem that I've seen is the installer wants to add a circuit from the main building to the detached garage for a large air compressor or maybe a welder when he/she already has a small panel in the garage for the lights and plugs. That is clearly not permitted. The solution is to install a large enough feeder to the garage to handle the existing load and also the added load.

I assume this three way that originates in the detached structure has to be AFCI because the other switch is in the main house.

Good catch niko! I never really looked at it that way. Sounds like a good recommendation for a code change.

This is one of the things I like about this website. A bunch of experience and perspectives come together all in one spot that all of us can benefit from

I doubt it has to be AFCI since a switch is not an outlet.

I see a code change for 2014.