# MC Strapping Question



## rjo430 (Nov 18, 2015)

I installed a piece of MC between two boxes a couple days ago. The boxes are mounted on opposite sides of the same stud to service two different rooms. The jumper cable between the two goes through a hole in the stud that's 11.5" from either of the boxes. I didn't want to have a tight bend in the wire, so I left a little bit of slack on either side of the stud so the MC was bending at a larger radius.

When I read the code it says that so long as the box has support within 12 inches you're good. However, I was told that the cable has to have straps on either side due to the extra slack in the MC from the wider bend. 

So, which is it? The way I read the code it seems to be saying that it's the distance between the strap and the box that relates to the 12 inches, not that the length of the wire must be 12 inches or less or else you have to have a strap. The extra slack adds probably 1.5 to 2 inches to the length, so the length of the wire before it hits the hole in the stud is 13.5 inches, but the distance down from the box to the hole is 11.5.


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## backstay (Feb 3, 2011)

Hole to box is less than 12 inches? You're not losing sleep over this?


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## rjo430 (Nov 18, 2015)

backstay said:


> Hole to box is less than 12 inches? You're not losing sleep over this?


I'm just seeing whether I'm right or not, and ultimately trying to prove my boss wrong when I bring it up on Monday.

And yes, I'm a complete wreck over this. Haven't slept in days. :laughing:


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## don_resqcapt19 (Jul 18, 2010)

The rule requires both securing and supporting within 12". Passing the cable through a hole in the stud only provides support. It does not secure the cable.


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## CADPoint (Jul 5, 2007)

A great application would be a cowboy slim!

Welcome to the Forum, enjoy the surf ~


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## rjo430 (Nov 18, 2015)

don_resqcapt19 said:


> The rule requires both securing and supporting within 12". Passing the cable through a hole in the stud only provides support. It does not secure the cable.


But you're allowed to run horizontally through studs and not need to strap it, and with Romex you can skip stapling it within 8 inches of a plastic box, so long as the hole in the wood stud is within 3 inches. The hole in that instance counts as both support and securing the wire, and my company has passed multiple inspections using this method, so is it different rules for MC then?


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## rjo430 (Nov 18, 2015)

Well now that I think about it, I guess with the 11.5" from the box it's going vertical up the stud, so there's no securing of the cable at that point and it definitely needs straps.


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## don_resqcapt19 (Jul 18, 2010)

rjo430 said:


> But you're allowed to run horizontally through studs and not need to strap it, and with Romex you can skip stapling it within 8 inches of a plastic box, so long as the hole in the wood stud is within 3 inches. The hole in that instance counts as both support and securing the wire, and my company has passed multiple inspections using this method, so is it different rules for MC then?


The Exception to 314.17(C) says you don't have to secure the NM to the box, if the NM is secured within 8" of the box. There is nothing in the NEC that says you don't have to do that if the hole in the structural member is within 3"....maybe that is a local rule.

I see nothing that permits you to eliminate the securing device that is required within 12" of the box for MC. There are rules for both NM and MC that permit holes in structural members to the the required supports for horizontal runs. These rules have nothing to due with the rules that require the cables to be secured and supported within 12" of the box.


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## Southeast Power (Jan 18, 2009)

I buy one of these for every box and use them.

http://www.erico.com/category.asp?category=R928


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## rjo430 (Nov 18, 2015)

don_resqcapt19 said:


> There is nothing in the NEC that says you don't have to do that if the hole in the structural member is within 3"....maybe that is a local rule.


That's good to know. My boss made it seem like this was written in the code, so I never looked into it. We did pass all our inspections using that method, but I don't want to start forming bad habits so I'll just start strapping in those cases as well. Thanks for all the info!


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## Wirenuting (Sep 12, 2010)

jrannis said:


> I buy one of these for every box and use them. http://www.erico.com/category.asp?category=R928


You buy colorful country buttons?


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## pete87 (Oct 22, 2012)

jrannis said:


> I buy one of these for every box and use them.
> 
> http://www.erico.com/category.asp?category=R928






Hey ... A Colorado Jim Cable Support is NOT AVAILABLE in BANGLADESH !!!

Whats up with That ?




Pete


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