Romex sheathing in a box

[dcooper]

Does the code actually specify how much of the outer jacket we are aloud to have in a box and I’ll if so, what is the code article

 

[Fred B]

Are you asking minimum or maximum?

 

[dcooper]

Are you asking minimum or maximum?

Maximum allowed

 

[tom baker]

Article 314

 

[tom baker]

Now if you want the Code rule, its section 314.17 B 2.
A code rule is a section...this rule has been in the NEC a long time for me its back to 1978

 

[Fred B]

Maximum allowed

I don't believe I've seen a maximum just a minimum. NEC 2017 shows a minimum of 1/4" beyond clamp for NM and 1/2" for UF.

 

[dcooper]

Now if you want the Code rule, its section 314.17 B 2.
A code rule is a section...this rule has been in the NEC a long time, I started wiring in 1978.

I got into a ‘discussion’ with a newly licensed electrician and mentioned the 1/4 (that’s what is was taught). He puts in in stripped wire in a box and does it later. I said it’s almost impossible to only have 1/4 of sheathing in the box. And he didn’t think I needed to be 1/4. I couldn’t remember where is was or if had been removed. Thanks!

 

[mortimer]

Unstripped cable in a box? Sounds like what a DIYer would do.

 

[dcooper]

Unstripped cable in a box? Sounds like what a DIYer would do.

Lic electrician.... then he goes back a cuts them all in

 

[tom baker]

I got into a ‘discussion’ with a newly licensed electrician and mentioned the 1/4 (that’s what is was taught). He puts in in stripped wire in a box and does it later. I said it’s almost impossible to only have 1/4 of sheathing in the box. And he didn’t think I needed to be 1/4. I couldn’t remember where is was or if had been removed. Thanks!

The only reason I can remember is I answer questions on the forum, making me look up the rules. You are welcome and thanks for using the forum

 

[LarryFine]

I said it’s almost impossible to only have 1/4 of sheathing in the box.

It's not difficult with an NM-cable stripper like this one; they work decently on UF, too:

 

[hbiss]

Unstripped cable in a box? Sounds like what a DIYer would do.

That's the way I always did it for 50 years. You don't have to look and play around with it to get that 1/4". Just shove it in, staple it, do whatever you have to do outside the box to make it look nice with no worries. Then use your NM stripper to reach into the box and strip the jacket. I actually have always used that cheap sheetmetal jacket stripper that none of you like. After that I reach in with a hawk-bill knife if it's a little longer than 1/4-1/2" to score it more, separate the conductors from the jacket then I slice it off. Doesn't take more than about 5 seconds.
You can put all your cables into the boxes then come back and strip them when you make them up later if you want.

-Hal

 

[infinity]

Now if you want the Code rule, its section 314.17 B 2.
A code rule is a section...this rule has been in the NEC a long time for me its back to 1978

My 2017 shows that wording highlighted meaning that it is new for the 2017. Prior to the 2017 there was no 1/4" minimum rule if there was a connector or clamp in the box. There was a 1/4" rule when there was no clamp in the box and the NM was stapled within 8" of the box which you might be thinking of.

 

[480sparky]

Um... the 1/4" requirement first appears in the 1975 NEC, 370-7(c).

 

[LarryFine]

I was taught a fast way to strip NM by pinching a tear in the sheath with a corner of the tip of my pliers, then just pull.

 

[infinity]

Um... the 1/4" requirement first appears in the 1975 NEC, 370-7(c).

My 1975 codebook makes no mention of the 1/4" but does reference the 8" I mentioned in post #13.

1975 NEC:
If nonmetallic-sheathed cable is used, the cable assembly shall enter the box through a knockout opening. Clamping of individual conductors or cables to the box shall not be required where supported within 8 inches of the box.

 

[mikeames]

It's not difficult with an NM-cable stripper like this one; they work decently on UF, too:

View attachment 2555778

I like those but I strip before putting cable in. Otherwise these may be easier to reach in. I never liked the 90 deg and don't use it but its available.

 

[480sparky]

My 1975 codebook makes no mention of the 1/4" but does reference the 8" I mentioned in post #13.

My mistake. 1978.

 

[don_resqcapt19]

Um... the 1/4" requirement first appears in the 1975 NEC, 370-7(c).

Prior to the 2017 code the rule only applied to cables entering a non-metallic box. The change in 2017 added that requirement to metallic boxes.
The panel statement for the 2017 code change says:

The NEC does not presently provide a minimum cable sheath requirement for the metal boxes with cable clamps, as is addressed in 314.17(C) for nonmetallic boxes. This wording will provide a comparable requirement and assure that the cable clamp will not bear on unprotected conductors.

 

[jap]

The rule for leaving a 1/4" of sheathing on the cable on the inside of the box probably stemmed from those who always cut too much sheathing off.

To me the exact measurement of at least 1/4" of sheathing on the inside of the box is not really critical as long as there is at least some.

It's when the sheathing doesn't make it into the box, or, at times, even to the connector of the box is when it starts getting unprofessional.

JAP>