Alternating current systems from 50V to less than 1,000V that aren’t required to be grounded as per 250.20(B) must have _____.
a) ground detectors installed
b) the ground detection sensing equipment connected as close as practicable to where the system receives its supply
c) both (a) and (b)
d) ground fault protection for equipment
See answer and applicable Code reference
The correct answer is: c) both (a) and (b)
System grounding requirements are outlined in Part II of Art. 250. Section 250.21 focuses on alternating-current systems of 50V to less than 1,000V that are not required to be grounded. As outlined in 250.21(A) and (B), ground detectors are required for these systems and they shall be connected as close as practicable to where the system receives its supply.