When grounding motors, when is it permitted to omit a grounding conductor connection at the motor terminal housing?

A. This is never permitted.

B. Where a motor is installed as a part of factory-wired equipment that is required to be grounded.

C. When a separate bonding jumper is installed between the motor terminal housing and a made electrode, such as a driven ground rod of 8 ft length with 2 in. of ground rod exposed above the concrete surface.

D. When the motor terminal housing is double insulated.

Answer: B

Section 430.12(E) of the 2011 NEC outlines the requirements for motor terminal housings. An Exception to this section of the Code states, "Where a motor is installed as part of factory-wired equipment that is required to be grounded and without additional connection being required at the motor terminal housing during equipment installation, a separate means for motor grounding at the motor terminal housing shall not be required."

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.