Q. When I add a GFCI-protected receptacle in an existing circuit that does not have an equipment grounding conductor, can I add additional grounding-type receptacles on the load side of it?

A. Where no equipment grounding conductor exists in the outlet box for the receptacle, such as old 2-wire Type NM cable without an equipment grounding conductor, existing nongrounding-type receptacles can be replaced with one of the following [406.3(D)(3)(1), (2), and (3)]:

  • Another nongrounding-type receptacle.
  • A GFCI-type receptacle marked "No Equip¬ment Ground."
  • A grounding-type receptacle, if GFCI-protected and marked "GFCI-Protected" and "No Equipment Ground."
GFCI protection functions properly on a 2-wire circuit without an equipment grounding conductor because the circuit equipment grounding conductor serves no role in the operation of the GFCI-protection device.

Caution: The permission to replace nongrounding-type receptacles with GFCI-protected grounding-type receptacles doesn't apply to new receptacle outlets that extend from an existing ungrounded outlet box. Once you add a receptacle outlet (branch circuit extension), the receptacle must be of the grounding type, and it must have its grounding terminal connected to an equipment grounding conductor of a type recognized in 250.118, in accordance with 250.130(C).