Question about 314.16(B)(4)

[rfkline1]

I have a question about Article 314.16(B)(4). In my lesson plan I have a four inch square box containing a switch and a duplex receptacle. The switch is fed with 14 AWG wire. The receptacle is fed with 12 AWG wire. When calculating the double volume allowance for the devices, do you put the switch in the column for the 14 AWG wire, or do you put both devices in the column for the 12 AWG wire. I was always under the impression that both devices go in the 12 AWG column but one of my students pointed out that in the code book it says that the calculation is "based on the largest conductor connected to a device". That tells me that the double volume allowance for the switch should go in the 14 AWG column.[/code]

 

[jwelectric]

Re: Question about 314.16(B)(4)

I have a question about Article 314.16(B)(4). In my lesson plan I have a four inch square box containing a switch and a duplex receptacle. The switch is fed with 14 AWG wire. The receptacle is fed with 12 AWG wire. When calculating the double volume allowance for the devices, do you put the switch in the column for the 14 AWG wire, or do you put both devices in the column for the 12 AWG wire. I was always under the impression that both devices go in the 12 AWG column but one of my students pointed out that in the code book it says that the calculation is "based on the largest conductor connected to a device". That tells me that the double volume allowance for the switch should go in the 14 AWG column.[/code]

I always listen when a student talks. My preacher tells me that the children shall lead them.

The student is correct.

 

[JohnE]

Your student is correct, you calculate device fill based on largest conductor size connected to device. But, if memory serves me right, device fill used to be accounted for in the manner you have been teaching. Late '80's or early 90's. I'll try to remenber to check some old code books when I get home.