Size of ground in boxes with options

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George Stolz

George Stolz

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Say I've got a switch switching 14 wire, and an outlet on 12 wire in a two gang box.

I've been told that if you have #12 in a box, and #14 in a box, that the bonding (<--ah!) conductor for both devices in the box need to be the size of the largest ground, in this case #12.

True, False, Code references?
 
Re: Size of ground in boxes with options

Pierre,
But a switch/receptacle isn't a raceway or cable. Doesn't this code mean that you can run one bonding conductor for several circuits (in a medium such as EMT where that's an option)?

Jim,
You're talking about box fill, right? But that doesn't apply to the physical installation of a bonding jumper to a switch.
 
Re: Size of ground in boxes with options

250.122(C) Multiple Circuits. Where a single equipment grounding conductor is run with multiple circuits in the same raceway or cable, it shall be sized for the largest overcurrent device protecting conductors in the raceway or cable.
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Re: Size of ground in boxes with options

I tend to agree with George.

Lets take the example of a common residential practice similar to the one George describes. #14 NM enters box and terminates to a switch for the disposal. #12 enters the same box and terminates to a receptacle to serve the countertop.

I feel there is nothing in the NEC the prohibits one from bonding the two EGC's together and then extending a #14 to the switch strap and a #12 to the receptacle strap. If thats not the case, then if I were to bring a #8 into a box that also contains a switch, I would then be required to bond the switch with a #8? I don't think so.
 
Re: Size of ground in boxes with options

Count me in as agreeing with George and Bryan. I don't see where the code is specific on this issue.

In the same example, does 240.148 even require us to connect the #14 and #12 grounding wires together?
 
Re: Size of ground in boxes with options

Edit: I read it right on the fourteenth try.

[ January 12, 2005, 08:09 AM: Message edited by: georgestolz ]
 
Re: Size of ground in boxes with options

Yes, it does require them to be connected. They just have way too many words to get a simple concept across. :(

Still leaves my original post hanging in the air, though...

[ January 12, 2005, 08:12 AM: Message edited by: georgestolz ]
 
Re: Size of ground in boxes with options

I think Bryan has it right. Why wouldn't you bond a switch or receptacle with the correct size for the circuit the device is serving? I can't find anything.
 
Re: Size of ground in boxes with options

Originally posted by georgestolz:
Yes, it does require them to be connected.
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That was looking at the 2005, which bore a change bar. Looking at the 2002 at lunch yesterday, I'd say you're right. Per the 2002, it was keeping them separate.

So, last call: Are CO state inspectors nuts? :D
 
Re: Size of ground in boxes with options

Are CO state inspectors nuts?
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I wish to apologize, I meant no disrespect to the Colorado Electrical Board, it's inspectors, or any inspector in any jurisdiction. This was meant as a light-hearted comment that I phrased very poorly.

My apologies.

Edit x 2: I would hate for anyone to believe that I would have a grudge against inspectors. I'd like to be one some day, when I'm smarter. And, apparently, more diplomatic. :)

Editted: Misunderstanding, resolved.

[ January 20, 2005, 08:26 PM: Message edited by: georgestolz ]
 
Re: Size of ground in boxes with options

George if your saying that someone was offended by that statement then I would say yes, they are nuts. :roll: We are a nation of appologists and it is ridiculous.

[ January 20, 2005, 07:21 PM: Message edited by: electricmanscott ]
 
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