Crawl-space wiring

[nhurst]

I've got an older house with old 2 conductor wiring in place that I'm working on upgrading. The rooms next on the rewiring list have a combination of overhead and underfloor supplied outlets and I'd like them on the same breakers if possible, so I have some questions to put to the group to add in to my consideration:

1) Should I run my under-house wiring in conduit or is just the plain Romex good enough? I'm currently leaning toward running it through conduit, to ease future replacement/repair if it's ever needed. I'm thinking about the thinwall 3/4" galvanized pipe that I can bend with a regular pipe bender. I'm anticipating only 1 12/2 wire per pipe.

2) Since my rooms have a mix of under floor and overhead supplied outlets, can I wire both sets up to the same AFCI breaker in my central breaker box? Some of the other breakers I've installed have the screw down plate with 2 bumps on it (like this: n_n (where the "n" represents the bump and the screw penetrates through the "_")). I've done searches on the archives here, but I saw many mixed responses, so I wasn't sure what the current rules allowed, and I haven't installed an AFCI breaker, so I'm hoping someone who has can answer that question (BTW my breaker box is Square D).

Thanks for any responses!

-Nathan

[Todd H.]

Depends on your local codes, but yeah, conduit is superior. In Illinois here, for example everything's gotta go in conduit.

It would be handy to talk to a licensed electrician in your state though for an authoritative response.

-- Todd H.

[Mark Lloyd]

My panel is a square D, and the extra breaker is marked. You're allowed 2 wires if they're both copper and no larger than 10 gauge. I also have an AFCI breaker for that panel. It allows single wires only (the other side of the clamp is covered up).

[RayV]

I don't have a copy of the NEC but I think you can only put individual wires through conduit not romex.

[mm]

Why? If you keep them on different breakers, then when one breaker trips, or one circuit fails, you'll have other outlets in each room that still work.

It sounds like a bad idea to me.

P&M because I fancy my opinion to be important. If replying, please do so by post.

[nhurst]

Yeah, I did a lot of reading last night on the NG and other sources, and I decided that I would just use conduit on the outside of the house from the breaker box to the crawlspace, then tack the wires to the floor joists. This way it's not part of a conduit system, but providing protection to the wire, which is OK with the NEC from what I've read. I'm planning on only putting a max of 2 12/2 Romex wires through 3/4" thin-wall EMT, with a run of maybe 5 feet from the box to where the wire will penetrate into the crawlspace.

The reason I'm wanting to combine overhead and subfloor circuits is that I'm wanting to keep some confusion out of the mix. I'm planning on having the outlets in all the rooms on AFCI and the lighting for the rooms on another, normal circuit breaker. That way if the AFCI trips we can still have light in the rooms, and vice versa. The Square D AFCI breakers I got don't allow for 2 conductors to be directly screwed down onto them, so I'm just going to combine the wires and run a pigtail to the breaker, which my research here has led me to believe is OK.

Thanks for all the responses. This NG has been a great tool in helping me get what I need to do figured out. :-)

-Nathan