Q. The wiring of each mobile home shall be subjected to a ____ minute, ____ volt dielectric strength test (with all switches closed) between live parts (including neutral) and the mobile home ground. Alternatively, the test shall be permitted to be performed at ___ volts for ___ second(s). This test shall be performed after branch circuits, luminaires (fixtures), and appliances are installed.

A) 10, 240 and 550, 10
B) 5, 480 and 600, 2
C) 1, 900 and 1,080, 1
D) There are no required tests for mobile homes, RVs, or any type of structure.

Answer: C
Testing requirements of this type are unique to mobile homes and are noted in sections 550.17(A), 551.60, and 552.60(A) of the 2005 NEC.

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.