Using a rigid box spacer between the service panel and an outlet box

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w2tq

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My usual practice when placing an outlet box (e.g., Raco 8232 quad) near a service panel is to mount the box on the same backboard about an inch away from the panel. I then run the Romex cable through clamp connectors (e.g., Halex 3/8" no. 20511) mounted in the knockouts in the panel and the box.

I recently came across a video where rigid box spacers (e.g., Halex no. 91641) were used between the panel and box. While this makes for a very neat installation, shielding the Romex cable from damage, one concern I would have is the lack of clamps preventing the movement of the cable when working in the panel or the box, notwithstanding the rigidity of the Romex. Of course, additional clamps (plastic, metallic) could be used in conjunction with the rigid box spacer, but that would make for one or two additional components in already tight quarters. I haven't tried this so it's not clear whether the back of the box would be flush with the backboard or is supported by the box spacers.

I welcome any comments including whether the code addresses this configuration (I was not able to find any provisions directly addressing the issue).
 
I would use an offset nipple, which would allow for different KO depths to the mounting surface.

Also, you need not worry about clamping conductors in a box-to-box connection; just use wires.

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LarryFine-

Thanks. Just to confirm, clamp-free wires would be acceptable in a box-to-service panel configuration?
 
I agree with Larry an offset nipple is a cheap and simple way to line up KO's that don't match. When the KO's do line up I use one of those fittings. The fact that the conductors can move within the fitting doesn't matter, no different than using a short piece of raceway.
 
w2tq said:
LarryFine-

Thanks. Just to confirm, clamp-free wires would be acceptable in a box-to-service panel configuration?
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Clamp-free like as in you are shoving NM through the nipple from the box to the panel? Why would you do that?? Go out to your truck and get some THHN.

And no, you can't use the stripped conductors from scraps of NM. Matter of fact with only two inches of intact jacket left within the nipple I wouldn't consider that sleeving the NM.

-Hal
 
hbiss -

Thank you. If I understand your comment correctly, that's why I have always run the intact Romex from the breaker, out of the panel through a Halex NM clamp in the panel knockout, through a second clamp mounted on the Raco box, and then to its termination (pigtails, outlet, etc.).
 
electrofelon said:
Oh none of us would ever do such a thing, I'm very hurt you would even consider we would do that. We all also would never use romex inners scraps to make pigtails in a box......
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Pigtails in a box are fine, but you definitely will burn the place down if you run those conductors through a raceway, even if it is just a really short nipple.
 
hbiss said:
Clamp-free like as in you are shoving NM through the nipple from the box to the panel? Why would you do that?? Go out to your truck and get some THHN.

And no, you can't use the stripped conductors from scraps of NM. Matter of fact with only two inches of intact jacket left within the nipple I wouldn't consider that sleeving the NM.

-Hal
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Those that are exclusively "house ropers" often don't have single conductors available to use for this.

Some might be ok with buying some until they find out they at least need to buy reels of both black and white, and maybe even green.
 
kwired -

Thank you. Just to be clear, in post #9, I wrote "intact Romex," by which I meant fully-sheathed cable running continuously from the circuit breaker (after attaching the hot, neutral, and ground as appropriate in the particular panel) all the way through to the Raco box. Only then are the three individual conductors exposed.

Perhaps there's a more elegant way of achieving the connection, but for now I am going to stay with the arrangement I outlined in the first paragraph of the initial post.

Thank you all for your comments and suggestions.
 
w2tq said:
kwired -

Thank you. Just to be clear, in post #9, I wrote "intact Romex," by which I meant fully-sheathed cable running continuously from the circuit breaker (after attaching the hot, neutral, and ground as appropriate in the particular panel) all the way through to the Raco box. Only then are the three individual conductors exposed.

Perhaps there's a more elegant way of achieving the connection, but for now I am going to stay with the arrangement I outlined in the first paragraph of the initial post.

Thank you all for your comments and suggestions.
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I kind of have no problem with what you are doing, if you want to nit pick enough technically you have a raceway wiring method and not a cable wiring method and running cable within is first not necessary, second there is securing method for a cable in this situation other than maybe screw some clamp to the enclosure or use an adhesive mount and a cable tie to it. Then as mentioned if you would strip the entire jacket off the cable technically the conductor within is not marked with a conductor type and therefore is not a conductor recognized by 310.104. Chances are it is the same thing as THHN but no marking means not recognized. This conductor was part of a listed cable assembly and if fine when used in that assembly.

And also if using a metallic raceway or fitting, you wouldn't need to run a separate EGC (that is part of your cable) as the raceway/fitting can be used as an EGC.
 
I would remove the NM sheath, leaving 2"of jacket for a fitting that's an inch long is ridiculous.
 
w2tq said:
My usual practice when placing an outlet box near a service panel is to mount the box on the same backboard about an inch away from the panel. I then run the Romex cable through clamp connectors in the knockouts in the panel and the box.
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I don't see a problem with doing it that way other than I've never seen it done that way. Looks stupid and like someone was cutting corners. At least if you are going to do it, put the box farther away on the backboard and staple the Romex over to it. That way the length of Romex actually does something and it looks like there was a reason for using it.

Now, I just looked at the video you posted. The usual electrical advice given on the internet.

w2tq said:
I haven't tried this so it's not clear whether the back of the box would be flush with the backboard or is supported by the box spacers.
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Typically when locating a box next to a panel like this, it would be rare to find a knock out at exactly the right depth that aligns with the box knock out so that the box sits on the backboard and you can use two screws to fasten it in place. If you look closely, because this guy used a straight nipple or "box spacer" into the nearest panel knock out, the box is actually about 1/4" off the board with only the box spacer supporting it. That's no good. The box can't hang from the raceway, which in this case would be the box spacer.

This is why an offset nipple like Larry shows in post #2 is used. Just turn it to the desired position to line up with the box and desired panel knockouts and screw your box in place to the board. Then tighten the locknuts. Shove your #14 or #12 black and white THHN through from the panel to the receptacle and wire it up. This is actually faster than screwing with lengths of Romex and looks professional.

w2tq said:
Of course, additional clamps (plastic, metallic) could be used in conjunction with the rigid box spacer, but that would make for one or two additional components in already tight quarters.
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It's clear that you don't understand other wiring methods besides NM (Romex). The nipple between the box and panel is a raceway which is another Chapter 3 wiring method. As such you only need to run individual conductors through it like the black and white stripped lengths of conductors that you get when you strip the jacket off Romex. (But you really should use new lenghts of THHN because by Code they need to have "THHN" printed on them.) There's no such thing as clamps since the conductors terminate on each end in an enclosure. And since this is a metallic raceway, it provides the ground connection between the panel and box so you don't have to worry about a ground wire. However, I would provide a green ground pigtail from your receptacle ground screw to a green ground screw in the threaded hole the box has for it in the back.

-Hal
 
hbiss said:
Clamp-free like as in you are shoving NM through the nipple from the box to the panel? Why would you do that?? Go out to your truck and get some THHN.

And no, you can't use the stripped conductors from scraps of NM. Matter of fact with only two inches of intact jacket left within the nipple I wouldn't consider that sleeving the NM.
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I didn't mean to imply sticking with the NM; I do carry "real" wire, too.

That's what I meant when I said "Yep, just like any conduit installation."
 
I don't know why one would use rope between two surface mounted boxes. unless they don't have THHN . That is why I see such hack work sometimes.
 
Sierrasparky said:
I don't know why one would use rope between two surface mounted boxes. unless they don't have THHN . That is why I see such hack work sometimes.
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It was explained above. If a company mainly does houses for developments or mainly residential new construction then you deal with NM. No reason for THHN or any other single conductor. You install a panel recep, and what do you use? I see nothing wrong with it, and every person on here at some point has disregarded minor violations at some point. I would laugh if someone wired the whole house in NM then got to the panel recep with a 2" offset and said "Hold on a min let me go to my truck to cut 12" of thhn for this nipple. That does not make you a hack. The key point is this is in a residence not commercial or otherwise.
 
mikeames said:
I see nothing wrong with it, and every person on here at some point has disregarded minor violations at some point.
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Yeah, I agree and I've done it at times too. But I we feel we must point the out Code requirement so at least the person who didn't know now knows and if the inspector catches it doesn't feel bad when he is busted.

-Hal
 
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