Code Q&A: Grounding Requirements for A/C Equipment on a Roof

March 23, 2022

Test your knowledge of the NEC.

Courtesy of www.MikeHolt.com.

Based on the 2020 NEC.

Q. When does the NEC require an equipment grounding conductor of the wire type for air-conditioning or refrigeration equipment installed on the roof and connected through a metallic raceway?

See answer below.

A. Where air-conditioning or refrigeration equipment is installed on the roof and connected with a metallic raceway, an equipment grounding conductor (EGC) of the wire type must be installed within outdoor portions of metallic raceway systems that use compression-type fittings [Sec. 440.9].

Air-Conditioning and Refrigeration Equipment Grounding and Bonding

The outdoor portions of rooftop metallic raceways with compression fittings are exposed to a higher likelihood of physical damage and often left stepped on and unbroken from roof activities such as snow removal or a roof repair/replacement. The installation of the EGC of the wire type within the outdoor portions of metal raceways provides reassurance of the effective ground-fault current path.

These materials are provided to us by Mike Holt Enterprises in Leesburg, Fla. To view Code training materials offered by this company, visit www.mikeholt.com/code.

About the Author

Mike Holt

Mike Holt is the owner of Mike Holt Enterprises (www.MikeHolt.com), one of the largest electrical publishers in the United States. He earned a master's degree in the Business Administration Program (MBA) from the University of Miami. He earned his reputation as a National Electrical Code (NEC) expert by working his way up through the electrical trade. Formally a construction editor for two different trade publications, Mike started his career as an apprentice electrician and eventually became a master electrician, an electrical inspector, a contractor, and an educator. Mike has taught more than 1,000 classes on 30 different electrical-related subjects — ranging from alarm installations to exam preparation and voltage drop calculations. He continues to produce seminars, videos, books, and online training for the trade as well as contribute monthly Code content to EC&M magazine.