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#95181 - 09/03/05 05:55 PM Fill in blue boxes
kyelectric Offline
Member

Registered: 08/30/05
Posts: 64
Could anyone help me determine the fill on the blue plastic nail on box(4"x2"). Sometimes I have been in the situation where I needed to pull 4 12/2 w/G's in the blue box to connect to other circuits. I only count all the grounds 1 time, each individual conductor 1 time, the yoke (switch or receptacle) 2 times and each wire nut (clamp) 1 time. When I total this up it's 8 wires, 1 ground, 3 wire nuts, and 2 for the yoke. Total 14. I have seen this done many times in other jobs but it seems to be ok with most inspectors. Does anyone have some good input on this?

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#95182 - 09/03/05 06:08 PM Re: Fill in blue boxes
Ralpha494 Offline
Member

Registered: 05/19/04
Posts: 71
Loc: Pewaukee,WI,USA
IMHO the wire nuts aren't clamps so you don't count them. If you don't put in a device (just a blank cover) you get 2 more back. It should end up being 8 wires plus 1 ground for a total of 9 (or 11 with a device).

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#95183 - 09/03/05 06:31 PM Re: Fill in blue boxes
gfretwell Offline


Member

Registered: 07/20/04
Posts: 9058
Loc: Estero,Fl,usa
The biggest single gang carlon nailup I have seen is the 3¼ deep and that is 22 cu/in, That is still too small for 11 #12s. (9 wires and the device)

2¼ x 11 = 24.75
_________________________
Greg Fretwell

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#95184 - 09/04/05 10:09 PM Re: Fill in blue boxes
georgestolz Offline
Member

Registered: 06/26/05
Posts: 90
Loc: Fort Collins, CO, US
 Quote:
Sometimes I have been in the situation where I needed to pull 4 12/2 w/G's in the blue box to connect to other circuits. I only count all the grounds 1 time, each individual conductor 1 time, the yoke (switch or receptacle) 2 times and each wire nut (clamp) 1 time.

As mentioned above, wire nuts are not clamps. See 314.16.

Clamps attach the cable to the box, not conductors together.

The easiest way to keep these things straight when first getting them straight, IMO, is to go down the list one by one:

So 4 12-2's with 1 device are
8 insulated conductors (314.16(B)(1))
0 Clamps (314.16(B)(2))
0 Support Fittings (314.16(B)(3))
2 counts for 1 device (314.16(B)(4))
1 count for all EGC's (314.16(B)(5))


Is 11 conductors x 2.25 = 24.75 cu.in.

That's way over for a single gang, even Carlon. (gfret, box fill is something best understood when the same math is done four different ways. )
_________________________
-George

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#95185 - 09/05/05 05:26 AM Re: Fill in blue boxes
Mvannevel Offline
Member

Registered: 03/19/03
Posts: 29
Loc: Hesperia, Michigan, USA
And for those of us whose arithmeticer's don't work so good, Carlon boxes have the maximum number of each size conductor marked in the back of the box. Takes the guesswork out of it if you're not handy with the math.

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#95186 - 09/05/05 05:40 AM Re: Fill in blue boxes
iwire Offline
Moderator

Registered: 01/05/03
Posts: 4343
Loc: North Attleboro, MA USA
Nice job Just George


You got sucked in didn't you?

Don't blame me.
_________________________
Bob Badger
Construction & Maintenance Electrician
Massachusetts

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#95187 - 09/05/05 07:11 AM Re: Fill in blue boxes
georgestolz Offline
Member

Registered: 06/26/05
Posts: 90
Loc: Fort Collins, CO, US
Well, I ran out of stuff to do at my normal haunt.

Everybody's enjoying their three-day weekend. Did you see me hanging off the rock?

-George S.
_________________________
-George

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