Conductor markings
- Thread starter TTwizted
- Start date
- Status
Carultch
Senior Member
- Location
- Massachusetts
No NEC requirement to mark conductor length. There are product standards for the interval to mark the print legend on the wire, but no requirement to mark the length.
Some cable products contain length markings on the print legend, so you can see that you install it from the 80 ft mark and end at 200 ft mark, to tell you that it is 120 ft installed, but this is a feature and not a requirement.
Length matters with regards to:
1. Voltage Drop, which is a recommendation as opposed to a hard rule. Some local energy efficiency codes or equipment-specific requirements may require you to stay within certain voltage drop limits, but other than that, it is not enforceable when only the NEC applies.
2. Parallel conductor sets. To preserve the symmetry and make sure current divides as uniformly as possible, it is a requirement to not build any intentional difference among the conductors in parallel. This includes length. Most people do realize that it is a difficult goal cannot build them exactly the same length, because one of the conduits takes the outside track around a bend, and you would be correct. You likely cannot get it exact. Ideally, you would put a slack loop in the wire for the set that is in the shorter conduit to compensate.
Last edited:
- Location
- New Jersey
- Occupation
- Journeyman Electrician
Generally there are NEC requirements that the color needs to encircle the conductor, that can be nothing more than one turn around the conductor if you're using tape. A Sharpie marker line can be even narrower as long as you can see it.
- Location
- New Jersey
- Occupation
- Journeyman Electrician
One such section is 250.119(A).
- Location
- New Jersey
- Occupation
- Journeyman Electrician
- Status