dnbob
Senior Member
- Location
- Rochester, MN
In a 3 gang box with 2 switches on #14 and 1 recept. on #12, do you use the #12 for all yokes or only the rec. when figuring box fill? Thanks
box fill
- Thread starter dnbob
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G
Guest
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Re: box fill
Brevity is a good thing online, but I'm not quite with you. Can you post back and fill in the gaps? Or, just edit your post above? That way we can give you a better & safer answer.
Brevity is a good thing online, but I'm not quite with you. Can you post back and fill in the gaps? Or, just edit your post above? That way we can give you a better & safer answer.
big john
Senior Member
- Location
- Portland, ME
Re: box fill
If I understand dnbob correctly, he's saying he has a three-gang box with three devices (two switches and one receptacle). The two switches are wired with #14, the receptacle is on #12 and he wants to know how to calculate the box-fill.
His question was, do you calculate the box fill by using the #12AWG column of table 314.16(A).
Here's my answer: You'd probably calculate it by finding the volume of the box you're working with (E.g.: 4x4x1.5 inches = 21 cubic inches) and then calculate the fill for each conductor based on table 314.16(B).
E.g.:
Six #14 conductors = 12 cubic inches
Three #12 conductors = 6.75 cubic inches.
Box fill for those conductors = 18.75 cubic inches.
Hope that helps.
-John
If I understand dnbob correctly, he's saying he has a three-gang box with three devices (two switches and one receptacle). The two switches are wired with #14, the receptacle is on #12 and he wants to know how to calculate the box-fill.
His question was, do you calculate the box fill by using the #12AWG column of table 314.16(A).
Here's my answer: You'd probably calculate it by finding the volume of the box you're working with (E.g.: 4x4x1.5 inches = 21 cubic inches) and then calculate the fill for each conductor based on table 314.16(B).
E.g.:
Six #14 conductors = 12 cubic inches
Three #12 conductors = 6.75 cubic inches.
Box fill for those conductors = 18.75 cubic inches.
Hope that helps.
-John
G
Guest
Guest
Re: box fill
How do you come up with six #14's?
What about the adds for the devices, clamps, & the connectors?
../Wayne C.
[ October 01, 2003, 11:25 AM: Message edited by: awwt ]
How do you come up with six #14's?
What about the adds for the devices, clamps, & the connectors?
../Wayne C.
[ October 01, 2003, 11:25 AM: Message edited by: awwt ]
gregoryelectricinc
Senior Member
Re: box fill
The aswer to the original question, if I understand corrctly, is YES. You would figure each device as two #12 conductors in this case.
The aswer to the original question, if I understand corrctly, is YES. You would figure each device as two #12 conductors in this case.
big john
Senior Member
- Location
- Portland, ME
Re: box fill
-John
I was just giving an example to show how it might be calculated. I just assumed one piece of Romex for each device; two pieces of 14 and one piece of 12. I wasn't actually trying to calculate a solution to dnbob's problem, I'm sure he can do that.
-John
dnbob
Senior Member
- Location
- Rochester, MN
Re: box fill
Sorry for the brevity, but Gregoryelectric had the answer I was looking for, I think. When the code book references this, 314.16B, the last few words are something like use the wire size connected to "That" yoke or strap, so I am a little confused. I do agree that everything should be brought to #12, perhaps it is a matter of opinion? What would a Masters test require to get the box fill question correct?
Sorry for the brevity, but Gregoryelectric had the answer I was looking for, I think. When the code book references this, 314.16B, the last few words are something like use the wire size connected to "That" yoke or strap, so I am a little confused. I do agree that everything should be brought to #12, perhaps it is a matter of opinion? What would a Masters test require to get the box fill question correct?
ryan_618
Senior Member
- Location
- Salt Lake City, Utah
Re: box fill
I have to disagree with you guys. I believe it is permissible to use a #14 volume allowance on the yoke/strap that the 14 energizes, even if the yoke/strap next to it is #12.
My basis for this is as follows: Notice in the first part of 314.16(B)(4), it implies that a yoke or strap contains devices . Later on in that sentance it states the volume allowance shall be determined by the largest conductor conected to a device or equipment supported by THAT strap .
Just my opinion, and I hope it helps,
I have to disagree with you guys. I believe it is permissible to use a #14 volume allowance on the yoke/strap that the 14 energizes, even if the yoke/strap next to it is #12.
My basis for this is as follows: Notice in the first part of 314.16(B)(4), it implies that a yoke or strap contains devices . Later on in that sentance it states the volume allowance shall be determined by the largest conductor conected to a device or equipment supported by THAT strap .
Just my opinion, and I hope it helps,
Re: box fill
dnbob,
Have been looking this over also in the NEC book and in the illustrated guide book to the NEC 2002 and I am leaning towards 4 cu.in per each switch and 4.5 cu.in for the receptacle.
Thats just how I interpet the information, but undertand the confusion from the way it is worded in 314.16(b)(4).
John
dnbob,
Have been looking this over also in the NEC book and in the illustrated guide book to the NEC 2002 and I am leaning towards 4 cu.in per each switch and 4.5 cu.in for the receptacle.
Thats just how I interpet the information, but undertand the confusion from the way it is worded in 314.16(b)(4).
John
Re: box fill
In my opinion the devices would be counted as 2 conductors according to the actual size conductor connected to that particular device. my understanding is that the yoke or strap is pertaining to the yoke or strap on the device itself, therefore each device would be counted according to the size of the conductor landed on that particular device.
In my opinion the devices would be counted as 2 conductors according to the actual size conductor connected to that particular device. my understanding is that the yoke or strap is pertaining to the yoke or strap on the device itself, therefore each device would be counted according to the size of the conductor landed on that particular device.
dnbob
Senior Member
- Location
- Rochester, MN
Re: box fill
I agree that the code does strongly suggest that you should use the awg connected to each strap, I guess I have heard so many different opinions, that I thought I would post this for some help. Thanks guys!
I agree that the code does strongly suggest that you should use the awg connected to each strap, I guess I have heard so many different opinions, that I thought I would post this for some help. Thanks guys!
big john
Senior Member
- Location
- Portland, ME
Re: box fill
That'll teach me to be confident about things :roll: , I figured I had that question pinned down. But based on the responses you guys are giving, dnbob doesn't seem to be asking about anything nearly as straight-forward as box fill for different conductor sizes.
I took a look at 314.16(B)(4) and couldn't make heads or tails of how it related to this.
Could someone explain exactly what's being asked here?
Thanks a bunch.
-John
That'll teach me to be confident about things :roll: , I figured I had that question pinned down. But based on the responses you guys are giving, dnbob doesn't seem to be asking about anything nearly as straight-forward as box fill for different conductor sizes.
I took a look at 314.16(B)(4) and couldn't make heads or tails of how it related to this.
Could someone explain exactly what's being asked here?
Thanks a bunch.
-John
ryan_618
Senior Member
- Location
- Salt Lake City, Utah
Re: box fill
Big John: The question being asked is this: If I have two receptacles in a box, one connected with #14 and the other connected with #12, how I figure volume allowances for the receptacles... (2) #12 allowances or (1) #14 allowance and (1) #12 allowance?
You've already seen my response.
Big John: The question being asked is this: If I have two receptacles in a box, one connected with #14 and the other connected with #12, how I figure volume allowances for the receptacles... (2) #12 allowances or (1) #14 allowance and (1) #12 allowance?
You've already seen my response.
G
Guest
Guest
Re: box fill
My first read was that it was a box fill/wire fill question. But now I understand it's actually a device fill calculation question. In mixed AWG do you figure each device at 2x#12 or 2x#14? Now I understand the question, and it's already been answered. Cool!
My first read was that it was a box fill/wire fill question. But now I understand it's actually a device fill calculation question. In mixed AWG do you figure each device at 2x#12 or 2x#14? Now I understand the question, and it's already been answered. Cool!
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