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Old 09-05-2012, 12:03 PM   #1
Join Date: Jul 2012
Location: Ontario, Canada
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Box sizing

I am doing some box sizing calculations, and am a little stumped.

Lets say you have a receptacle which pigtails to another receptacle. So you have power in, power out, and the device.

By my calculations this is:

4 - hots and neutrals
1 - ground
1 - clamps
2 - device
= 8

If its all #14 then you need 16 cu.in box. Most standard receptacle boxes are 12.5 cu.in.


Does this mean that a standard box cannot even be used unless its an end point? Am I missing something?

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Old 09-05-2012, 02:11 PM   #2
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Box sizing

In Canada you have to figure the wire nuts also.
That box with a 14/2 feed would have 2+2+2+2+4=12 cu.
2 for the hot, 2 for the neutral, 2 for the ground, 4 for the device, and 2 for the internal clamp.

You need to double your hot and neutral from 4 to 8 since you have an in and out cable, so the min. box is 16 cu.

Yes I am a Pirate, 200 years too late. "Jimmy Buffett"

Last edited by jbfan; 09-05-2012 at 02:16 PM.
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Old 09-05-2012, 03:10 PM   #3
Join Date: Jul 2012
Location: Ontario, Canada
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Box sizing

I can't seem to find any mention of clamps or ground wires in the CEC

Only 1 for every insulated conductor, 1 for every pair of wire nuts, 2 for every device

Am I missing something?
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Old 09-05-2012, 03:39 PM   #4
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Box sizing

That is not a standard box in the US, and I doubt it is a standard box in Canada.
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