Box fill and wire nuts

10300 Views 7 Replies 3 Participants Last post by HouseHelper, May 2, 2011

zephed666

Discussion Starter · May 2, 2011

Hello:

I have a question amout box fill with wire nuts and pigtails. I have a 2 gang box with 12/2 coming in and two 12/3 wires going out. The box is for 2 switches. I was having problems getting 5 wires under one wire nut so I pigtailed them to another wire nut. So what it looks like in the box now:

-3 white wires under 1 wire nut
-3 green under 1 wire nut pigtailed (4 in total under the first wire nut) to another wire nut with 2 grounds running to each switch (so 3 in that wire nut)
- 3 blacks under 1 wire nut pigtailed (4 in total under the first wire nut) to another wire nut with 2 more wires running to eache switch

So there are 5 wire nuts in the box. This box is in a shallow wall and is only 25 cu. inch. Is this acceptable for box fill?

Here is a rough sketch of what it looks like:

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Jim Port

· #2 · May 2, 2011

Your box is too small. For box fill you have 13 #12's x 2.25 cubic inches = 29.25.

Under the NEC pigtails and wire nuts do not count towards fill. Under the CEC wire nuts count towards fill.

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zephed666

Discussion Starter · #3 · May 2, 2011 (Edited)

Jim Port said:
Your box is too small. For box fill you have 13 #12's x 2.25 cubic inches = 29.25.

Under the NEC pigtails and wire nuts do not count towards fill. Under the CEC wire nuts count towards fill.

How did you get to 13 #12's? Any suggestions to fix this, again it is a shallow wall?

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HouseHelper

· #4 · May 2, 2011

one 12/2 = 2
two 12/3 = 6
ground =1
two switches = 4
total = 13, assuming you have no internal clamps.

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zephed666

Discussion Starter · #5 · May 2, 2011

HouseHelper said:
one 12/2 = 2
two 12/3 = 6
ground =1
two switches = 4
total = 13, assuming you have no internal clamps.

Again, how can I rememdy this in the shallow wall? Do they make a shallow 2 -gang box that is as wide as a 3 gang?

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HouseHelper

· #6 · May 2, 2011

How shallow is the wall? What is behind it? Is there a wall covering?
You may be able to use a 4" square box (metal) with a deep mud ring to gain enough room, or a three gang box with one space in the cover blanked.

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zephed666

Discussion Starter · #7 · May 2, 2011

HouseHelper said:
How shallow is the wall? What is behind it? Is there a wall covering?
You may be able to use a 4" square box (metal) with a deep mud ring to gain enough room, or a three gang box with one space in the cover blanked.

I was using an old work box since I didn't want to tear out a portion of the wall. The new work box I just picked up will fit and it is 32 cu. in. and states 14/12 wires on it. So I should be ok with the box fill now.

Is how I connected it in the diagram inpost 1 a problem? Or is it acceptable to use multiple pigtail and wire nuts since they son't fit under 1 nut?

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HouseHelper

· #8 · May 2, 2011

The multiple wirenuts is not a problem, but you could also use larger wirenuts (blue) or Wago-style pushin connectors that accept eight wires.

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Box fill and wire nuts

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