Grounding electrode conductors smaller than ______ shall be in rigid metal conduit, IMC, PVC conduit, electrical metallic tubing, or cable armor.
a) 10 AWG
b) 8 AWG
c) 6 AWG
d) 4 AWG
See answer and applicable Code reference
The correct answer is: c) 6 AWG
Section 250.64 of the 2014 NEC covers the installation requirements of grounding electrode conducts. Securing and protection rules are outlined in 250.64(B). As noted in a portion of this Section, "A 6 AWG grounding electrode conductor that is free from exposure to physical damage shall be permitted to be run along the surface of the building construction without metal covering or protection if it is securely fastened to the construction; otherwise, it shall be protected in rigid metal conduit (RMC), intermediate metal conduit (IMC), rigid polyvinyl chloride conduit (PVC), reinforced thermosetting resin conduit (RTRC), electrical metallic tubing (EMT), or cable armor."