Question on wall box for 50amp outlet

[RaskyR1]

My wife and I are doing all the electrical in our new garage and bedroom addition, aside from the new panel, and I have a question on the wall boxes I have for my 50amp outlets. I wanted some extra room for wiring up the 6-2 romex so I went with a plastic 2 gang box. After I got back home and started installing things I noticed The knockouts were too small for the wiring so I cut a hole in the side and installed a wire clamp. When the electrician I hired came to upgrade our service and install my new sub panel said he had never seen that done before and didn't know if the inspector would give me a hard time about it. I know I saw some 2 gang boxes at the store with plastic clamps already built in like this so I didn't think it would matter. Thoughts? I already have them installed and really don't want remove them unless I have to.


Thanks!
Rasky

 

[theoldwizard1]

You never know with inspectors ! Looks kosher to me, but I am not the inspector !!

 

[jim111]

The clamp is installed backwards if it matters to your inspector

 

[RaskyR1]

You never know with inspectors ! Looks kosher to me, but I am not the inspector !!

The clamp is installed backwards if it matters to your inspector

Thanks! I can change that easy enough.

 

[Stuff]

The inspector could say that the plastic box is not listed for this field modification.

 

[Cmreschke]

^^^this. For the the first 5 years of my residential career we drilled out 1/2" holes in plastic cut in boxes and used them for island and meninsula plugs. We installed ent fittings and surf tube for sleeving. It was always kosher until they decided that it was a violation of listing. As that plastic box wasn't designed for drilling a hole. I think it's **** personally. They told us if it was meant to have holes in it then the manufacturer would put some in it. I call hog wash. Some steel and some Carlon pvc boxes don't have any kos in them, are we not suppose to make our own in those?

 

[bczygan]

Can you use these for surface mounting of 30 and 50A receptacles?

Bill

 

[Dagny]

Most here would be ok with it.

 

[Cmreschke]

Can you use these for surface mounting of 30 and 50A receptacles?

Bill

Not a dryer or range plug. It's too small.

 

[Dagny]

Can you use these for surface mounting of 30 and 50A receptacles?

Bill

not big enough.

 

[bczygan]

not big enough.

I've used one for a 30A 220V and it physically worked with #10 romex.

But you're saying it doesn't meet minimum sizes per code?

Bill

 

[Cmreschke]

I don't have the size of the box in front of me but its 6s won't fit in that box with a 50 amp range plug I'd bet physically with the 6 inches of free conductor required, plus ground splice and all. If you say you put a 30 amp in with 10s hey I believe it. I've seen 10 gallons of **** in a 5 pound bucket too. Doesn't mean it was legal though. Ymmv. The receptacle shown above 8s designed for a 2 gang box or 4 square with raised cover.

 

[nadogail]

There are some installations where a plastic box is permitted but the job screams for a deep metal box.

 

[Mustang51js]

I dont know how you couldnt fit the wire in with the clamps in box. You could cut the tab between the two and put it that way,but the wire usually will fit in the single spot

 

[Norcal]

The inspector could say that the plastic box is not listed for this field modification.

And I would agree with the inspector. Use a 4X4 or 4 11/16 square box with a 2 gang ring mounted to a block

 

[Cmreschke]

And I would agree with the inspector. Use a 4X4 or 4 11/16 square box with a 2 gang ring mounted to a block

In a day and age where we are allowed to construct our own junction boxes, this is just silly not allowing a 1/2 or 3/4 inch hole to be made in a plastic box.

 

[Jess]

Get the bigger boxes for this. It makes connecting the wires and mounting a lot easier.

 

[gregtwojeeps]

Get the 2 and 1/8 " deep box though with 1/2" plaster ring shown on bottom pic. Use 5/8 " ring even better . . Just be sure ring will be flush with finished wall surface. Be sure box is secured well. jmo

 

[matt_i]

And I would agree with the inspector. Use a 4X4 or 4 11/16 square box with a 2 gang ring mounted to a block

^^^^ This. You want a metal box anyway in my opinion. This is a setup where you have to push and pull with decent force on the plug. If the plastic threads strip out you get to start over and do it again. The metal box forces you to put a more serious wood block behind it, not the cheap nails. Nothing irritates me more than spongy electrical boxes.

Home Depot around here seems to have a big advantage over Lowes in this department, they have a full lineup of Raco 4" dished covers. In other words, the receptacle mounts to the ring, the ring is screwed into the diagonal corners of the box. The ring is trim and structural, all at the same time.

Edit: check out Raco 810C.

 

[bobmulry]

Hi,

That looks like a NEMA 6-15 receptacle which is 15 amps / 240 volts and not 50 amp..........................

Bob

 

[Cmreschke]

Hi,

That looks like a NEMA 6-15 receptacle which is 15 amps / 240 volts and not 50 amp..........................

Bob

No way. Looks like a 3 wire range receptacle. It fills a 2 gang box.

 

[bobmulry]

No way. Looks like a 3 wire range receptacle. It fills a 2 gang box.

Would that have a 50 amp rating and what would the NEMA # be???????????????????????????????

 

[Aceman]

It's a 30 amp 250v receptacle.

http://www.leviton.com/OA_HTML/ProductDetail.jsp?partnumber=5372&section=42418

He needs a 6-50R for 50 amp 250v.

I would not use that nail on box either. I would probably use a 4 square deep bracket box with a 4 square box extension and a mud ring if I was looking for plenty of room. How much wall thickness is there? Did you use 2x4 or 2x6 or?

 

[Cmreschke]

I stand corrected it is a 30 amp not 50 amp. But still a far cry from 15 amp.

 

[TTA89]

Great timing... I'm going to install my 6/2 50amp welder receptacles and I was going to use the plastic 2 gang boxes. You guys make a great point about pushing and pulling on the plugs. I'm going to try the deep metal boxes, I have 2x6s so it shouldn't be a problem. My biggest problem is finding the right parts at Home Depot... Most of the time I have a picture with no name. "Do you know where I can find this?" ha ha.

 

[RaskyR1]

Thanks for all the reply's guys. It seems like it really depends on the inspector so I'm just going to email him the pics to see if he has issues with it before I go ahead and replace it, since it's already installed. My wife has talked to him a few times now and he's been very helpful. I chose plastic boxes simply because I will be washing cars inside often and it just seemed to make more sense, no other reason.

It is a 50amp (6-50R) that is going there but I also have (2) 30 amp outlets going in as well and just held it up for a picture reference. It will be used for EV charging as I work on new Tesla's occasionally and the owners appreciate a full charge when they pick up their cars.

I dont know how you couldnt fit the wire in with the clamps in box. You could cut the tab between the two and put it that way,but the wire usually will fit in the single spot

That was an option too but as noted above that would technically be modifying the plastic box, no? The metal clamp idea was a suggestion from a friend who used to be an electrician after I mentioned seeing these Carlon boxes, which are essentially doing the same thing.

 

[Norcal]

But they have been listed for the application.

 

[sands35]

You could use these:

http://www.garvinindustries.com/electrical-junction-boxes/6-square-junction-boxes/1-1-2-to-3-deep

Nice and big.

Assuming 30 amps, that would be #10 wire. A box fill calculator says min 15 square inches (if I did it right....), which would be anything, but a 4-11 box would be better given the slightly larger volume over a 4 square.

http://www.constructionmonkey.com/calculations/electrical/boxfill

 

[RaskyR1]

But they have been listed for the application.

True

You could use these:

http://www.garvinindustries.com/electrical-junction-boxes/6-square-junction-boxes/1-1-2-to-3-deep

Nice and big.

Assuming 30 amps, that would be #10 wire. A box fill calculator says min 15 square inches (if I did it right....), which would be anything, but a 4-11 box would be better given the slightly larger volume over a 4 square.

http://www.constructionmonkey.com/calculations/electrical/boxfill

I actually ran 8-2 romex to the 30amp boxes in case I wanted/needed to change them to 40amp later.

 

[mike93lx]

Unless fixing it will cause a big disruption, I personally would not reach out and ask. Seems like you are welcoming the failure that might not have been issued otherwise. That said, i would use a metal box too.

 

[RaskyR1]

Unless fixing it will cause a big disruption, I personally would not reach out and ask. Seems like you are welcoming the failure that might not have been issued otherwise. That said, i would use a metal box too.

Thanks! It will be a few weeks before the inspection and I still need to run wire for all the overhead lights so I may just take your (and the others above) advice and swap them out for metal boxes.

 

[rexer]

I mounted my 50 amp receptacle box for my welder just below the panel box with 8/2 wire and a plastic blue box.

Didn't want too start cutting all the sheet rock..

I guess its ok, nice and tight when I put the plug in and take it out..

 

[nadogail]

If you do decide to stay with the plastic box and it breaks, be prepared for a thousand "We told you to switch to a metal box" messages.

 

[TTA89]

Noobie question here... If you use one of the 4 inch metal boxes, how do you ground it with 6/2 wire coming in?

 

[md21722]

6/2 means 2 insulated wires and 1 uninsulated ground in a bundle.

 

[md21722]

How did you cut the hole in the side of the box?

 

[TTA89]

6/2 means 2 insulated wires and 1 uninsulated ground in a bundle.

Right... So I figure you build a ground tail off the box with whatever, 12 or 14 gauge and then how do you connect it to the 6 gauge wire that is going to the receptacle? In a 12 or 14 gauge scenario I would wire nut the feed wire ground, the box ground tail and a tail from the receptacle right? But in this case the wire is too thick with 6 gauge so whats do you do?

Maybe I'm overthinking this...

 

[Jsf721]

Rasky. It's jsfm35x. Hit the inspector with a old rupes and get a mark II. Lol

 

[Norcal]

The grounding conductor in 6/2, and 6/3 NM is 10 AWG, run a little extra cable into the metal box and wrap the 10 gauge bare conductor around a ground screw, no need for splices & a quick and easy way to bond the box. 12 AWG is not acceptable for a grounding pigtail above 20 amperes.

 

[RaskyR1]

How did you cut the hole in the side of the box?

hole saw bit and then a dremel tool to smooth it out.

Rasky. It's jsfm35x. Hit the inspector with a old rupes and get a mark II. Lol

LOL! Small world! How's it going man?

The grounding conductor in 6/2, and 6/3 NM is 10 AWG, run a little extra cable into the metal box and wrap the 10 gauge bare conductor around a ground screw, no need for splices & a quick and easy way to bond the box. 12 AWG is not acceptable for a grounding pigtail above 20 amperes.

Thanks for the tip!