Box Fill Requirements ???

[Joe Camel]

I would like to know what are the maximum number of wires allowed in a box enclosure,as per CEC ...does the bare bonding wire count as 1 wire? And what about dimmers...I've seen slide dimmers that will take up half the space in a standard 12.5 cu. in. switch/outlet box, does this change the rule? As you would have to consider that dimmers can be, and most often are, added after the initial installation. If wire overheating is the issue would it not also matter whether your ( saturated ) box is at the beginning of the end of a run?
The NEC states :The number of conductors in boxes and conduit bodies is regulated by Section 314.16. Conductors that run through a box are counted as one conductor. Each conductor originating outside of the box that terminates inside the box is counted as one conductor. All the grounding conductors for each grounding system, usually the equipment grounding system and the isolated grounding system, are counted as one conductor, at the size of the largest contained equipment grounding conductor for the system. Devices on a single yoke or strap mounted in or on a box are counted as two conductors. One conductor is counted for each set of hickeys, fixture studs, or cable clamps inside the box. Exterior cable clamps and interior locknuts are not counted. Conductors that do not leave the box, such as pigtails, are also not counted.
***How does this compare to the C.E.C.?
Looking forward to your comments.

[bigrockk]

1) The bare wire does not count

2) For dimmers and the like the following applies: Rule 12-3036(3)

Where a box contains a device having a dimension greater than 2.54 cm between the mounting strap and back of the device, the total usable space shall be reduced by the space occupied by the device, calculated as 82 cm3 multiplied by the depth of the device in centimetres divided by 2.54 (for example, a device having a depth of 4 cm would occupy a space of 129 cm3, that is, 82 times 4 divided by 2.54).

If you have access to a code book you can find the complete rule starting at 12-3036 and tables 22 & 23

Hope this helps.

<font color="#a62a2a" size="1">[ January 22, 2003 11:24 PM: Message edited by: bigrockk ]</font>