Originally Posted By: jtedesco
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If I see a newer (Romex) Type NM cable, (not NM-B) with a white, black, and bare EGG wire that was run out of an existing metal box with a "Knob and Tube" 14 AWG circuit, and the box is large enough, can I consider that as being legal?
My answer was No, because the metal box was not properly grounded by an EGC run with the circuit, and that it could be possible to run an equipment grounding conductor from the point of entry where it would be connected to the water pipe (not further that 5 feet into the building) and run it to the box and secure it to the box so it can be available for connection of the EGC in the new cable.
This has been allowed for many years because of the following:
|250.134(B) With Circuit Conductors. By an equipment grounding conductor contained within the same raceway, cable, or otherwise run with the circuit conductors.
Exception No. 1: As provided in 250.130(C), the equipment grounding conductor shall be permitted to be run separately from the circuit conductors.
Joe Tedesco, NEC Consultant