Listed flexible metal conduit can be used as the equipment grounding conductor if the length in any ground return path does not exceed 6 ft and the circuit conductors contained in the conduit are protected by overcurrent devices rated at ______ or less.
a) 15A
b) 20A
c) 30A
d) 60A
See answer and applicable Code reference
The correct answer is: b) 20A
Part VI of Art. 250 covers equipment grounding and equipment grounding conductor requirements. The acceptable types of equipment grounding conductors that can be run with or enclosing the circuit conductors are outlined in Sec. 250.118. As noted in 250.118(5), listed flexible metal conduit must meet four conditions to serve as an equipment grounding conductor. One of those conditions, (5)(b), states: "The circuit conductors contained in the conduit are protected by overcurrent devices rated at 20A or less."