Tracing multiwire circuits

[mtnelect]

I wish you luck but circuits can get moved around in panels so the numbers out in the field could become meaningless. IMO for that reason the CMP will not want to require physical wire number markings in junction boxes.

That is encouraging! According to the NFPA they are now working on a schedule for 2026 this week at their convention.

 

[mtnelect]

I don't want to discourage you I was just expressing my opinion as to what I think the CMP would do. I actually wrote the original proposal to allow wire markers to be used for conductor identification. Back when they first required a cable tie or tape to identify which circuit conductors went together there was no code provision to allow only the use numbers on the conductors.

In commercial work we always number each home run conductor in both the junction box and the panel so for that work I like the idea.

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Sorry, I replied to the wrong thread !

 

[wwhitney]

He stated that not all neutrals are grounded. What AC system would have an ungrounded neutral?

250.20 specifies the cases where it would be allowed for the neutral to be ungrounded. Per 250.20(B), for systems rated 50V to 1000V,, the line to neutral voltage would need to exceed 150V, and the system could not be a 3 phase 4-wire wye or delta. E.g. a 480V single phase 3-wire, or 2-phase 5-wire, or "hexaphase" 7-wire.

Cheers, Wayne