minimum length for a circuit?

I have been pondering this idea, but looking for validation. I want to wire up a 40 to 50 amp circuit 220V for a welder.

Due to the high price of copper and stiffness of 6-8 Awg wires. Can I save time and money by installing a electrical box /w receptable just above the (in-wall) breaker panel, in the same cavity, without going through the header? I am thinking of using an old work box, the kind that clamps on drywall.

Is there anything in the NEC code that states you cannot have the recepticle too close to the breaker, for example 2 feet of wire?

If not, what about the same situation but using a metal box mounted to a stud on the drywall, with the wire coming in from behind the box (part of dry wall cut out). Since the higher ampere plugs are stiffer, I am thinking a old work box might not take the abuse well. Wires will be clamped inside the box.

Thanks

Reply to
jeremy_ho
Loading thread data ...

Nothing wrong with that. You can use a surface receptacle rated for the amperage of the welder as well

Reply to
RBM

Yes, but be careful when cutting that box into the wall. The majority of your circuits feed into the top of the breaker box and damaging any would be a bad thing.

Nope. I've attached 100's of recepticle boxes directly to surface mounted boxes.

Dave S(Texas)

Reply to
putt

The wire clamps on a plastic old work box are usually not large enough to accommadate 8/2 or 6/2 romex. You can use 2- 2" x 3" x 3.5" switch boxes with 3/4" knockouts ganged together and a 3/4" squeeze connector. Mount them next to a stud and use madison bars and some wood screws for support. Alternatively, as RBM suggested you can use a surface mount receptacle or you can install a 4 11/16" square x 2 1/8" deep metal box with a surface cover. Both metal boxes will need to have a grounding screw installed.

Reply to
John Grabowski

I did think about the clamps on plastic boxes and I think I will go with a metal box that has a clamp bar, is that what you mean by madison bar?

Here a complication arises, I believe I did not see any NM wires less than 10 Gauge in both local big box stores. Do I need to go to a more specialized place?

Must I use Romex? Can I use THNN? (i.e, is stranded wire OK to connect at the breaker?) or other variety?

Thanks

Reply to
jeremy_ho

No. A madison bar supports the recessed box by applying pressure against the drywall. It is separate from the box and you would normally use two. Sometimes they are called support bars, support clips, or gem box supports. In addition to using them I prefer to drill a hole in the side of the box and shoot a #6 sheet metal screw into the stud for additional support. There are also metal clips available with a screw on them that attach to each edge of the switch box. When the screw is tightened it compresses the clip to wedge the box tight against the drywall.

For the larger romexes you need to use a squeeze connector. The internal metal wire clamps are not big enough. Get 2 switch boxes with 3/4" ko's such as a Raco 591.

I have seen #6 and # 8 romex at Home Depot, but you can certainly go to an electrical supply house and try to buy it by the foot.

You can use THHN, but it must be in a conduit. It is not approved as an open conductor. Stranded is fine to connect to a circuit breaker.

Reply to
John Grabowski

Ocultar texto de la cita -

u got the idea and works just do it you got it

Reply to
hdezhdez71

I just bought 125' of 6/3 at HD for $150. That's not terribly expensive; if you were local I would give you 10' of it!

Reply to
Toller

imho:

I've never heard of a min length requirement, but you might have some weird local codes.

One suggestion, have the receptacle far enough away, that if a plug is tugged out, it doesn't hang up on any other wires.

tom @

formatting link

Reply to
Just Joshin

HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.