rough-in wire length vs. box fill


Old 02-11-05, 11:40 AM
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rough-in wire length vs. box fill

What is the max length for rough-in wires extending from a box? Is it standard, or varies by location? (CA,US)

I understand the min rough-in wire length to be 6in (3in past face), though I prefer a bit longer (6in past face) as it makes it easier to work with, and the local inspectors seem to like that too. But I don't know what the max wire length is, and it seems that it must be specified somewhere, for box fill reasons, right? (imagine someone trying to cram 3 ft of wire into a 22in^2 box)

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Old 02-11-05, 12:32 PM
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No max as I have ever seen.
Box fill is a non-issue with regard to this. Each "conductor" is counted, regardless of it's length. Pigtails are not even counted.
Old 02-11-05, 05:14 PM
Join Date: Nov 2002
Location: Orange County, CA
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First splice

Having done my first splice last weekend, I realize now after reading this thread that I did not leave enough wire in the box. I am still reading the three recommended books on wiring a house but one of the first steps to re-wiring my house is to put in an attic ladder. Wouldn't you know it, the best place for the ladder was above a cable, so I spliced it to a longer new wire. The first splice I did was very difficult and I saw that I had not allowed enough wire to make it easier. I used very small boxes because this is a temporary splice until I re-wire to get rid of the aluminum wiring. What is the danger to leaving the splices without lots of spare wire in the box?
Old 02-11-05, 06:29 PM
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I prefer to leave about a foot inside the box at rough-in. You can always cut it shorter but you can never cut it longer. Of course, this makes it more important to carefully stuff that wire into the back of the box so that the drywallers don't cut it.

Wire expands and contracts with temperature, especially in an attic. If the cable is too tight and there is insufficient slack in the box, the connection is subject to stress. Insufficient wire also makes future repairs and modifications more difficult.

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