I believe this is what IWIRE refers to
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.
[ROP 2–10]
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 neutral-conductor currents. [ROP 2–11]
(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. [ROP 2-10]
very interesting!!
Charlie
[This message has been edited by cpal (edited 08-20-2006).]
