Q. What are the rules in sizing equipment grounding conductors?
A. Equipment grounding conductors (EGCs) of the wire type must be sized not smaller than shown in Table 250.122, based on the rating of the circuit overcurrent device; however, the circuit EGC isn’t required to be larger than the circuit conductors [250.122(A)].
If ungrounded conductors are increased in size from the minimum ampacity that would be required for the load,