# Old work boxes for MC



## subelect (Nov 25, 2007)

I had to install two new outlets in a wood & finished drywall wall this afternoon. The entire building had been wired with EMT. 
I got lucky and was able to run my MC from an existing 4 square down the wall to my new boxes. I have never run across this before; having to install additional outlets inside a finished wall with MC.
I was curious what everybody else uses for old work when you can't use NM.
Do you use the old "gem" boxes with F-strap supports or is there another product out there that would work better? The problem that I have with gem boxes is that it is such a bear to get a GFCI to fit in one. Even the new Leviton slim GFCIs take up alot of space. 
Thanks,
Rick


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## HARRY304E (Sep 15, 2010)

subelect said:


> I had to install two new outlets in a wood & finished drywall wall this afternoon. The entire building had been wired with EMT.
> I got lucky and was able to run my MC from an existing 4 square down the wall to my new boxes. I have never run across this before; having to install additional outlets inside a finished wall with MC.
> I was curious what everybody else uses for old work when you can't use NM.
> Do you use the old "gem" boxes with F-strap supports or is there another product out there that would work better? The problem that I have with gem boxes is that it is such a bear to get a GFCI to fit in one. Even the new Leviton slim GFCIs take up alot of space.
> ...


Just try to use the deepest old work box you can..


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## jefft110 (Jul 7, 2010)

I've been known to uni-bit a 7/8" hole into a plastic cut-in, and bring mc into it, a time or two.


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## HARRY304E (Sep 15, 2010)

jefft110 said:


> I've been known to uni-bit a 7/8" hole into a plastic cut-in, and bring mc into it, a time or two.


Are you saying that install MC cable in plasic boxes??


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## Dennis Alwon (May 9, 2009)

HARRY304E said:


> Are you saying that install MC cable in plasic boxes??


Why not if it is the end of the line and bonded at the other box?


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## jefft110 (Jul 7, 2010)

HARRY304E said:


> Are you saying that install MC cable in plasic boxes??


Yes sir.


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## 480sparky (Sep 20, 2007)

Just use deep gem boxes.


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## jefft110 (Jul 7, 2010)

Dennis Alwon said:


> Why not if it is the end of the line and bonded at the other box?


Exactly. The only issue would probably be the "altering" of the listed plastic box.


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## jefft110 (Jul 7, 2010)

HARRY304E said:


> Are you saying that install MC cable in plasic boxes??


Harry, before you have a stroke, I've only done this a couple of times in a real pinch. Not something I'd make a habit of doing.


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## Dennis Alwon (May 9, 2009)

480sparky said:


> Just use deep gem boxes.


This is what I have done but a GFCI is tight in there-- width not depth.


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## HARRY304E (Sep 15, 2010)

Dennis Alwon said:


> Why not if it is the end of the line and bonded at the other box?


That is true but when someone comes along and adds to it they already have a plasic box box they may not know enough to change it to a metal box. 


And what about
2011 NEC
*
250.118 Types of Equipment Grounding Conductors.
*
(10) Type MC cable that provides an effective ground-fault
current path in accordance with one or more of the
following:
a. It contains an insulated or uninsulated equipment
grounding conductor in compliance with 250.118(1)
b. The combined metallic sheath and uninsulated
equipment grounding/bonding conductor of interlocked
metal tape–type MC cable that is listed and
identified as an equipment grounding conductor
c. The metallic sheath or the combined metallic
sheath and equipment grounding conductors of the
smooth or corrugated tube-type MC cable that is
listed and identified as an equipment grounding​conductor


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## TOOL_5150 (Aug 27, 2007)

im missing the point of it being end of the line vs daisy chained. I can run an MC to a plastic box, as long as I use a bonding bushing, correct? So why could I not have 2 coming in a plastic box and bond em both?


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## HARRY304E (Sep 15, 2010)

TOOL_5150 said:


> im missing the point of it being end of the line vs daisy chained. I can run an MC to a plastic box, as long as I use a bonding bushing, correct? So why could I not have 2 coming in a plastic box and bond em both?


What are going to bond them to?


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## electricalperson (Jan 11, 2008)

i dont think there is anything wrong with installing MC in plastic boxes as long as there is a way to bond the MC and you dont drill 7/8 inch holes in boxes that are not listed. a 1/2 inch bonding bushing would work


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## Rob Roy. (Jun 21, 2011)

WOW! That's a bit hackish, don't you think? Not that I haven't done it before either.


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## HARRY304E (Sep 15, 2010)

electricalperson said:


> i dont think there is anything wrong with installing MC in plastic boxes as long as there is a way to bond the MC and you dont drill 7/8 inch holes in boxes that are not listed. a 1/2 inch bonding bushing would work


Some how i do not see the bonding bushing being used it would be a waste of time and aggravation of just getting 1/2" bonding bushings when you could just get a metal box in the first place:thumbsup:


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## TOOL_5150 (Aug 27, 2007)

HARRY304E said:


> What are going to bond them to?


The ground wire that is in the MC maybe?


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## TOOL_5150 (Aug 27, 2007)

HARRY304E said:


> Some how i do not see the bonding bushing being used it would be a waste of time and aggravation of just getting 1/2" bonding bushings when you could just get a metal box in the first place:thumbsup:


I dont know of any GOOD SIZED cut in metal boxes though.. thats the main issue I run into.


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## HARRY304E (Sep 15, 2010)

TOOL_5150 said:


> I dont know of any GOOD SIZED cut in metal boxes though.. thats the main issue I run into.


You can get them up to 4" deep...:thumbsup:


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## HARRY304E (Sep 15, 2010)

TOOL_5150 said:


> I dont know of any GOOD SIZED cut in metal boxes though.. thats the main issue I run into.


What do you use if you are using BX ?


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## electricalperson (Jan 11, 2008)

HARRY304E said:


> Some how i do not see the bonding bushing being used it would be a waste of time and aggravation of just getting 1/2" bonding bushings when you could just get a metal box in the first place:thumbsup:


i was just saying if someone wanted to use a plastic box. those arlington siding boxes for example. if you use them in a commercial area wired in MC you need a bonding bushing


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## B4T (Feb 10, 2009)

This brings up an interesting point.. I used these duplex connectors today with 1900 boxes.. 

The connector takes care of bonding the cables together for MC cable and snaps into a standard 1/2" KO..

But I have never used them in plastic boxes..


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## Dierte (May 12, 2009)

Dennis Alwon said:


> This is what I have done but a GFCI is tight in there-- width not depth.


 That's what she said:thumbup:
I've added countless gfi's by cutting in an old work box. Just put a wrap or two of tape around the gfi so there's no chance of arcing to the box and you should be good to go.


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## electricalperson (Jan 11, 2008)

Dierte said:


> That's what she said:thumbup:
> I've added countless gfi's by cutting in an old work box. Just put a wrap or two of tape around the gfi so there's no chance of arcing to the box and you should be good to go.


i dont think there is a way for the screws to hit the metal box because they are usually set back on the GFCI never really flush so they dont contact the side of the box. i still tape it


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## TOOL_5150 (Aug 27, 2007)

Dierte said:


> That's what she said:thumbup:
> I've added countless gfi's by cutting in an old work box. Just put a wrap or two of tape around the gfi so there's no chance of arcing to the box and you should be good to go.


You a union guy?


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## BBQ (Nov 16, 2010)

subelect said:


> I was curious what everybody else uses for old work when you can't use NM.
> Do you use the old "gem" boxes with F-strap supports or is there another product out there that would work better? The problem that I have with gem boxes is that it is such a bear to get a GFCI to fit in one. Even the new Leviton slim GFCIs take up alot of space.
> Thanks,
> Rick


We would use deep, metal old work boxes with built in MC clamps instead of NM clamps.

http://www.hubbellcatalog.com/raco/RACO_datasheet.asp?PN=600

We would also only bring one cable into it.


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## Techy (Mar 4, 2011)

BBQ said:


> We would use deep, metal old work boxes with built in MC clamps instead of NM clamps.
> 
> http://www.hubbellcatalog.com/raco/RACO_datasheet.asp?PN=600
> 
> We would also only bring one cable into it.



Those are cool until they want a GFI in a 2-7/8" stud wall.


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## BBQ (Nov 16, 2010)

Techy said:


> Those are cool until they want a GFI in a 2-7/8" stud wall.


Then they might get a two gang with a GFCI and duplex.:thumbsup:


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## subelect (Nov 25, 2007)

Thanks for your input.
I wound up being lucky enough to cut in right beside the stud. I used 4 square deep boxes screwed to the stud with No-Rise mud rings.
The big problem was that the customer wanted it done right away and we did not have the correct boxes in the shop. 
I don't know if the boss will have it inspected by AHJ or not. That was why I was leery of using plastic boxes drilled out to accept MC.
Thanks for all the advice.
Rick


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## BBQ (Nov 16, 2010)

subelect said:


> I used 4 square deep boxes screwed to the stud with


FWIW


> 314.23 Supports.
> 
> (B) Structural Mounting. An enclosure supported from a
> structural member of a building or from grade shall be
> ...


Not saying I have never screwed through the side of a box but it is good to know the rules.


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## B4T (Feb 10, 2009)

BBQ said:


> We would use deep, metal old work boxes with built in MC clamps instead of NM clamps.
> 
> http://www.hubbellcatalog.com/raco/RACO_datasheet.asp?PN=600
> 
> We would also only bring one cable into it.


I used those boxes recently for clock receptacles that were going to be used for picture lights..

Really tight fit and I had to pigtail stranded wire onto the receptacle because you can't "fold' the device into the box.. no room


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## BBQ (Nov 16, 2010)

B4T said:


> Really tight fit and I had to pigtail stranded wire onto the receptacle because you can't "fold' the device into the box.. no room


Operator error.


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## B4T (Feb 10, 2009)

BBQ said:


> Operator error.




Those clock outlets take up more room than a GFI.. it was a lot faster using pigtails than fighting with it..:thumbsup:

I installed (10) total..


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## BBQ (Nov 16, 2010)

B4T said:


> Those clock outlets take up more room than a GFI.. it was a lot faster using pigtails than fighting with it..:thumbsup:


Get back to me when you have to put a twist lock 30 amp receptacle in there with solid 10/4 MC. 

It can be done and without taking up more space with wirenuts.


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## HARRY304E (Sep 15, 2010)

BBQ said:


> Get back to me when you have to put a twist lock 30 amp receptacle in there with solid 10/4 MC.
> 
> It can be done and without taking up more space with wirenuts.



:laughing:

Those are fun...:thumbsup:


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## B4T (Feb 10, 2009)

BBQ said:


> Get back to me when you have to put a twist lock 30 amp receptacle in there with solid 10/4 MC.
> 
> It can be done and without taking up more space with wirenuts.


The wirenuts took up no space since I folded them under the top MC clamp..

I was looking for a fast effective way of getting the job done.. that was using stranded pigtails..

You should of used a (2) gang box for the T/L.. same as a 4/wire dryer receptacle.. 

If the box was existing.. the original guy was not planning his job correctly..


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## BBQ (Nov 16, 2010)

B4T said:


> The wirenuts took up no space since I folded them under the top MC clamp.


So you are a magician, you can make objects vanish.

Man you say some crazy stuff. :laughing:



> I was looking for a fast effective way of getting the job done.. that was using stranded pigtails..


Or wasteful and lazy, each of us can decide. 



> You should of used a (2) gang box for the T/L.. same as a 4/wire dryer receptacle..


Smart ass, it does not mount in a two gang like a dryer recpt.:no:




> If the box was existing.. the original guy was not planning his job correctly..


The thread is about old work boxes, that kind of takes the 'existing' out of it. 

You would miss me if I was gone. :thumbup:


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## user4818 (Jan 15, 2009)

BBQ said:


> We would use deep, metal old work boxes with built in MC clamps instead of NM clamps.
> 
> http://www.hubbellcatalog.com/raco/RACO_datasheet.asp?PN=600
> 
> We would also only bring one cable into it.


I save the unused MC cable clamps from 4" square boxes and swap out the clamps in a regular NM old work box. Obviously this is inefficient for large quantities but it saves me from stocking two kinds of boxes that I hardly ever need anyway. 

I agree with only one cable if you can do it.


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## OHMsFolly (Apr 16, 2011)

Standard oldwork box with internal clamps and use Madison bars. Pre strip the wire and tape the anti-short in place before fishing the wire it may be hard to push slop back ip the wall with the ply in place. We deal with old works in a rocked and plied wall all the time in server and tele rooms.


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## BBQ (Nov 16, 2010)

Peter D said:


> I save the unused MC cable clamps from 4" square boxes and swap out the clamps in a regular NM old work box. Obviously this is inefficient for large quantities but it saves me from stocking two kinds of boxes that I hardly ever need anyway.


I work the other way, I stock with MC clamps and modify them when I use NM. 



> I agree with only one cable if you can do it.


If it is 12 AWG you pretty much have no choice, two 12/2 MCs and a device is over the limit on a standard depth metal OW box.


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## user4818 (Jan 15, 2009)

BBQ said:


> I work the other way, I stock with MC clamps and modify them when I use NM.
> 
> If it is 12 AWG you pretty much have no choice, two 12/2 MCs and a device is over the limit on a standard depth metal OW box.


Right, but who cares? Why do you care so much about the code? :laughing::laughing:


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## BBQ (Nov 16, 2010)

Peter D said:


> Why do you care so much about the code? :laughing::laughing:


The NEC gives me a huge woody. :whistling2:


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## 220/221 (Sep 25, 2007)

The best thing I've found is the Bowers 53 owe. It has MC clamps in back and drywall clamps on opposite corners.


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## Hippie (May 12, 2011)

I like regular cut in boxes with ko's for the MC connector, and f clips. Fancy cut in boxes with wings and crap don't hold as well, aren't as universal and if there's **** in the way inside the wall they don't always grab like they should. I have no problem getting a gfi in one, it just requires a bit of finesse


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## BBQ (Nov 16, 2010)

Hippie said:


> I like regular cut in boxes with ko's for the MC connector, and f clips. Fancy cut in boxes with wings and crap don't hold as well, aren't as universal and if there's **** in the way inside the wall they don't always grab like they should. I have no problem getting a gfi in one, it just requires a bit of finesse


I agree 100% on all your points.


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## Dierte (May 12, 2009)

electricalperson said:


> i dont think there is a way for the screws to hit the metal box because they are usually set back on the GFCI never really flush so they dont contact the side of the box. i still tape it


 I know there is minimum chance of arcing, but it makes me feel better if I ever have to pull one out of there.


TOOL_5150 said:


> You a union guy?


no Y?


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## BBQ (Nov 16, 2010)

Dierte said:


> I know there is minimum chance of arcing, but it makes me feel better if I ever have to pull one out of there.


Shut the circuit off.


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## MarkyMark (Jan 31, 2009)

220/221 said:


> The best thing I've found is the Bowers 53 owe. It has MC clamps in back and drywall clamps on opposite corners.


From the first day I saw a plastic old work box twenty years ago, I've always wondered why they never made a metal box with the drywall clamps on them. Why these have never caught on? I wish someone stocked those around here, so we wouldn't have to mess with those stupid "F" clips!


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## McClary’s Electrical (Feb 21, 2009)

Rob Roy. said:


> WOW! That's a bit hackish, don't you think? Not that I haven't done it before either.


Thanks and I agree. I'm too embarrassed to read much more of this thread...


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## 220/221 (Sep 25, 2007)

Hippie said:


> I like regular cut in boxes with ko's for the MC connector, and f clips. Fancy cut in boxes with wings and crap don't hold as well, aren't as universal and if there's **** in the way inside the wall they don't always grab like they should. I have no problem getting a gfi in one, it just requires a bit of finesse


 
The problem I have with the KO's is that they are in the middle part of the box. With the clamp style connectors in back, you can more easily slip the box into the wall.

And, the old wing style boxes always have been and still are a pain in the ass.



> Why these have never caught on? I wish someone stocked those around here, so we wouldn't have to mess with those stupid "F" clips!


They haven't really caught on here either. I have to order them by the case (about $8 ea) as the supply houses don't stock them.


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## Phil DeBlanc (May 29, 2010)

Looks to me like Steel City & Raco both still make the proper box, they even make them for electricians who know how to install Madison Supports.

Blows even sells them
http://www.lowes.com/ProductDisplay...gId=10051&cmRelshp=sim&rel=nofollow&cId=PDIO1


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## Dierte (May 12, 2009)

BBQ said:


> Shut the circuit off.


Easier said then done sometimes. If the gfi won't reset, then how do I use my tracer to locate the circuit since 99% of the boxes aren't marked inside of them. And by the time I pop my head above the ceiling, find the jbox and hope that it's labeled, It would be alot quicker to just pull it out and replace.


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## Shockdoc (Mar 4, 2010)

I prefer OWC clips for Gem boxes over madison clips. Been doing a lot of that lately . The only difference I find is drilling larger holes and snaking the cable through with the connector on it . I run into problems occasionally with box sizing such as walls framed 2x3 on the flat, a 2 1/2 gem will work if the finish is plaster lathe, I had a couple lately where I had to squeeze two 12/2 s in a 2" gem box, not pretty.


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