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Using Blue Carlon Boxes - Remove Sheath Before or After Inserting Wire?

Using Blue Carlon Boxes - Remove Sheath Before or After Inserting Wire?

Old 04-06-16, 12:03 PM
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Using Blue Carlon Boxes - Remove Sheath Before or After Inserting Wire?

I seem to have some trouble with the Blue Carlon boxes. I don't know why but I'm not crazy about the internal clamps. I never know if I'm supposed to strip the Romex first, or if I should feed the cable before stripping. If I strip the sheath in the beginning, I'm always concerned about nicking the wires when I'm pulling the cable through. I've tried stripping the Romex after it's inserted, but I don't seem to be able to get it stripped far enough. I end up having a couple inches of sheath in the box. I have a lot of #12 wiring in my home, so that's what I primarily use. What is typically the best method?
Old 04-06-16, 12:11 PM
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I strip the sheath first. It can be a pain to insert into the boxes as the end of the sheath often catches, but usually a good tug will pull it through. The wire insulation is pretty tough...I don't think I've ever damaged it on a plastic box. I have been known to use a screwdriver to loosen the internal clamp a little if need be. The romex needs to be stapled close to the box anyway, the plastic clamp isn't really securing the cable.

Making the wires longer than needed helps give you something to tug on; they can be trimmed to proper length later.
Old 04-06-16, 12:37 PM
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I strip the sheath first and bend open the box clamp a little bit with the tip of my NM stripping pliers.
Old 04-06-16, 04:27 PM
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I strip sheath after inserting wire.
I never had problem with not being able to stripping sheath far enough.

What I do is score sheath (not cutting all the way) using a utility knife from as close as I can get in the box. As blade comes close to end of the wire, I apply more pressure which cuts sheath all the way. Then I separate sheath and pull.
Because there is score on the sheath, it easily peels off. After that, I simply cut off peeled off sheath.
I get about 1/2" of sheath remaining in the box.

Sheath can be peeled off without scoring as well. Just cut a split at the end and pull on it. But, this can be hard, especially on a larger gauge wires.
You can also choose to split sheath all the way with utility knife instead of scoring. But, you have to be careful not to damage wire insulation inside. As long as you stay in the middle and don't apply too much pressure you should be fine. Paper wrapping inside helps not damaging wire insulation as well.
Old 04-06-16, 06:57 PM
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I usually insert the full cable into the box, then strip it afterwards. I find the individual wires get caught and I usually end up hurting my hands in some way or another. You can be rougher with the whole cable, using a pair of linesman pliers to pull it into the box.

Once it's in the box and secured, I cut down the middle of the NM-B starting about 1/2" or 3/4" from the back of the box, cutting to the ground wire, being careful to not go near the black/white wires. Pull the sheath back and use diagonal cutters to cut it near the back of the box.

Old 04-06-16, 08:02 PM
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I cut the sheath with NM strippers, but leave the cut piece on until I get the cable in the clamp or box. Then pull the cut piece off.

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