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Conduit contains more than one pair of share-neutral circuits.

S

Span

Registered User
Joined
Nov 2, 2009
Messages
95
Location
CA
Residential panel upgrade, existing flex conduit contains more than one pair of share-neutral circuits enter panel enclosure "not NM", to prevent electrician from landing share-neutral both hot-wire on same phase. Is there any code

section that I can use to require electrician provide cable tie or tape to group them for identify each pair share-neutral

circuit.

span
 
If your under the 08 NEC this works.

210.4 Multiwire Branch Circuits.(A) General. Branch circuits recognized by this article shall be permitted as multiwire circuits. A multiwire circuit shall be permitted to be considered as multiple circuits. All conductors of a multiwire branch circuit shall originate from the same panelboard or similar distribution equipment.

FPN: A 3-phase, 4-wire, wye-connected power system used to supply power to nonlinear loads may necessitate that the power system design allow for the possibility of high harmonic currents on the neutral conductor.

(B) Disconnecting Means. Each multiwire branch circuit shall be provided with a means that will simultaneously disconnect all ungrounded conductors at the point where the branch circuit originates.

© Line-to-Neutral Loads. Multiwire branch circuits shall supply only line-to-neutral loads.

Exception No. 1: A multiwire branch circuit that supplies only one utilization equipment.

Exception No. 2: Where all ungrounded conductors of the multiwire branch circuit are opened simultaneously by the branch-circuit overcurrent device.

FPN: See 300.13(B) for continuity of grounded conductor on multiwire circuits.

(D) Grouping. The ungrounded and grounded conductors of each multiwire branch circuit shall be grouped by wire ties or similar means in at least one location within the panelboard or other point of origination.

Exception: The requirement for grouping shall not apply if the circuit enters from a cable or raceway unique to the circuit that makes the grouping obvious.
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Also note (B), handle ties required.
 
chris kennedy said:
If your under the 08 NEC this works.Also note (B), handle ties required.
Click to expand...
No matter what year NEC you're on, then I'd say 90.1© would cover it.
 
chris kennedy said:
90.1©??? You sure thats what you meant to site Ken?
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Yep. If you can't recognize a MWBC in a panel, you ain't got no business sticking your nose in there.

That said, CMP2 must think otherwise with their wonderful rewrite ('dummying down') of 210.4.
 
I think the code making panel got nervous about all the proposals calling for the complete elimination of MWBC's in total. It seems to me this was a way to get those sentiments calmed down, while not really changing the wiring method.

I think it is kind-of funny when a someone makes the claim that MWBC's are dangerous and shouldn;t be used when considering that every service installed is really a multiwire arrangement.
 
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