I just found this this morning.
2002 NEC section 210.7 - "Branch Circuit Outlet Requirements." part (C) states:
Where more than one branch circuit supplies more than one receptacle on the same yoke, a means to simultaneously disconnect the ungrounded conductors supplying those receptacles shall be provided at the panelboard where the branch circuits originated.
Raises a question about how to hook up a dual voltage device like a 15A 125V and 15A 250V set of receptacles on one yoke. Or the pair of neutrals and hots to a standard duplex with the tabs removed, where the hots originate from the same bus.
Al
