Q. Exposed non-current-carrying metal parts of small wind electric systems, such as towers,  turbine nacelles, other equipment, and conductor enclosures shall be connected to an equipment grounding conductor [in accordance with 250.134 or 250.136(A)] at what voltage level?

A. All voltage levels
B. 50V or more
C. 600V or more
D. 1,000V or more

Answer: A

As noted in Sec. 694.40(A) of the 2011 NEC, exposed non-current-carrying metal parts of small wind electric systems, such as towers,  turbine nacelles, other equipment, and conductor enclosures shall be connected to an equipment grounding conductor in accordance with 250.134 or 250.136(A) regardless of voltage.

Owen is the owner and president of National Code Seminars and the holder of master electrician certifications in 46 states. He can be reached at necexpert@aol.com.