In one- and two-family dwellings where it is not practicable to achieve an overall maximum primary protector grounding conductor length of 20 ft, a separate ground rod not less than _____ in length shall be driven and it shall be connected to the power grounding electrode system with a 6 AWG conductor.
a) 5 ft
b) 8 ft
c) 10 ft
d) 20 ft
See answer and applicable Code reference
The correct answer is: a) 5 ft
Grounding methods for communications systems are outlined in Part IV of Art. 800. As noted in Sec. 800.100(A)(4), the length of the primary protector bonding conductor or grounding electrode conductor shall be as short as practicable, not to exceed 20 ft. However, the Exception in this section notes the following:
"In one- and two-family dwellings where it is not practicable to achieve an overall maximum primary protector bonding conductor or grounding electrode conductor length of 20 ft, a separate communications ground rod meeting the minimum dimensional criteria of 800.100(B)(3)(2) shall be driven, the primary protector shall be connected to the communications ground rod in accordance with 800.100(C), and the communications ground rod shall be connected to the power grounding electrode system in accordance with 800.100(D)."