Wire Terminations at C/B's
- Thread starter Dynamite
- Start date
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IMM_Doctor
Senior Member
110.12 Mechanical Execution of Work.
Electrical equipment shall be installed in a neat and workmanlike manner.
Electrical equipment shall be installed in a neat and workmanlike manner.
110.12 is non-enforcible. Since when did it matter if a little copper showed? Use the strip gage on the side of the breaker, or whatever the instructions per 110.3(B) say. If torquing is required, do that. Move on.
- Location
- Logan, Utah
There is no specific code section that prohibits a copper conductor from being stripped a little bit long and having the copper visible at the breaker.
IMHO, 110.12 neat and workmanlike manner is unenforceable.
Chris
- Location
- Logan, Utah
Twoskinsoneman
Senior Member
- Location
- West Virginia, USA NEC: 2020
- Occupation
- Facility Senior Electrician
If I don't see at least a small amount of copper showing I would be worried the insulation is being crimped which could cause an actual problem
- Location
- New Jersey
- Occupation
- Journeyman Electrician
weressl
Esteemed Member
The problem is that 'little' is undefined.
The NEC will be of no help here.
The danger is flash-over and live exposed parts, so as a general guideline you would not want the uninsulated portion of the cable pass the perimiter of the surrounding case insulation. The danger here is that the freshly pulled insulation will shrink back, also aided by the heating cycles when the conductors get loaded up, gradually exposing more and more bare conductor. So as a practical matter, you want to cut as close as needed to minimize conductor exposure.
Pierre C Belarge
Senior Member
- Location
- Westchester County, New York
As there is no specific code limiting the measurement for the amount of bare copper that is exposed at the circuit breaker termination, I would say it comes down to experience.
weressl
Esteemed Member
I think that approach is a slippery slope. (See my previous comment about 'little'.)
I would rather say that it is one area that the NEC should address along with arc-over distances and minimum live-to-ground clearences per groups of voltages.
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LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
Just about all molded-case breakers have strip gauges molded into the side of the case. That's a good place to start, at least.
In my opinion, it's better to err on the side of maximum contact between the conductor and the terminal.
I agree that the ideal length is where no conductor shows and no insulation is pinched. I bother to trim when trimming out.
In my opinion, it's better to err on the side of maximum contact between the conductor and the terminal.
I agree that the ideal length is where no conductor shows and no insulation is pinched. I bother to trim when trimming out.
PetrosA
Senior Member
- Location
- Lancaster, Pennsylvania
I would say the ideal strip length is maybe 1/16" (2mm) beyond the lug or plate area. Longer than that and there's a risk that you could accidentally hit a live section of wire while installing or removing other wires in the panel.
- Location
- Massachusetts
Check out table 408.56
weressl
Esteemed Member
Forgot about that one.
I think this and the creepeage should be in a more general section, perhaps in the same section where acess and working spaces are defined around electrical equipment. In the same area I also would like to see some minimum working space defined around the components that would make serviceability an issue to eliminate knucklebusters.
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