box fill

[doyle88]

I recently failed an inspection for over fill of some boxes. I understand that a device counts as two, and each hot wire counts as one. The inspector also counts the ground. I have yet to find anything that clearly goes eather way. The box im using is a standard single gain nail on. (18 cu.in.) I ran a feed,a switch leg and a power out.By anyones calculations am I in the wrong.

 

[Pierre C Belarge]

314.16(B)(1)-(5), with (5) being the one you want to pay attention to for your post.

 

[cpal]

I recently failed an inspection for over fill of some boxes. I understand that a device counts as two, and each hot wire counts as one. The inspector also counts the ground. I have yet to find anything that clearly goes eather way. The box im using is a standard single gain nail on. (18 cu.in.) I ran a feed,a switch leg and a power out.By anyones calculations am I in the wrong.

what gage conductors?
what wiring method?
how many insulated conductors ??
are you considering a grounded circuit conductor as a hot??? or is a grounded ckt conductor a ground??

 

[doyle88]

12-2 wire on a single pole switch

 

[doyle88]

12 gauge
3 hots
3 nuetrals
3 grounds

 

[Dennis Alwon]

12-2 wire on a single pole switch

So how many conductors do you have?

6 for the 3 pair of 12/2 and one for all the grounds. Now add 2 for the switch.

9 conductors multiply that by 2.25 and you are over.

 

[Dennis Alwon]

I use a 22.5 cu. inch box all the time. No problem with 3 pair of 12/2 cables.

 

[cpal]

12 gauge
3 hots
3 nuetrals
3 grounds

I think it's 9 conductors at 2.25 cu in or 20 .25 cu in fill so an 18 cu in box would be short by 2.25 cu in ???

read table 314.16 A and 16B read both paragraphs.

respond if you ave questions

hope this helps

 

[doyle88]

thank that helped i didnt know that the ground was one and each individual nuetral counted

 

[celtic]

12 gauge
3 hots
3 nuetrals
3 grounds

PLUS a device.

 

[Charles R. Miller]

Somebody wrote and illustrated a great series of articles on box-fill calculations in Electrical Contractor magazine. The series started July 2004 in the monthly column, ?Code in Focus.? Here is the link to the first of twelve articles:
http://ecmag.com/index.cfm?fa=article&articleID=5883
Charles

 

[gtm87]

plus any internal clamps the boxs may have, shouldnt apply to that tho.