I have a 14/2 (one circuit) and a 14/3 (two circuits), both Romex NM, coming into a regular steel handy box (2x4") and continuing on from there via outdoor cables (UF cable ?). Am I compliant with the NEC, considering it's three circuits and a total of 6 capped splices? It all fits in but you couldn't fit a smidge more.

  • handy boxes or the ones I use are only rated for indoor use, (I mentioin this because of the UF cable) is it inside or not in a wet location? the next question is how deep is the box? last is there an outlet in the box, that takes room from the calculation also. your conductors count for 2 cu in each – Ed Beal Nov 11 '15 at 21:22
  • So you have 1x 14/2 and 1x 14/3 coming in (as Romex), and 1x 14/2 and 1x14/3 coming out (as outdoor cable) of the box? – JPhi1618 Nov 11 '15 at 21:56
  • You may also want to check out This Link which shows detailed boxes and their cu in capacity. There are two listings there for "Handy Box", but they may defer from yours. Check out their examples on caculating box fill. – Kris Nov 12 '15 at 0:15

Short answer is you are way undersized on your box and it does not meet the National Electrical Code. Here's why:

Table 314.16(A) of the NEC does not list handyboxes for sizing but I am going to estimate they are the same size as a standard devices box of 2" deep. That would probably be generous. So, that would be about 10 cubic inches volume. The table says you can put 5 #14 wires in them. However, the code requires you to count each wire entering a box from outside once so when you make a splice it gets counted twice (314.16(B)(1)).

So, your example would be 10 wires total (5 in and 5 out) plus the ground for 11 wires (the grounds only get counted once no matter how many you have (314.16(B)(1)). Table 314.16(B) shows #14 wire needs 2.00 cubic inches per wire so you would need a box of 22 cubic inches.

Back to Table 314.16(A) and you would need a 4" square box 2 ⅛" deep or a 4 11/16" 1 ¼" deep box.

Happy Day!

  • 3
    If its a metal box that has internal clamps, that's a +1 on the number of conductors as well. – JPhi1618 Nov 11 '15 at 21:49

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