Code Q&A

Nov. 24, 2010

Q. What are the requirements for the point of attachment of a service drop?

A. According to 230.26, the point of attachment for service-drop conductors must not be less than 10 ft above the finished grade and must be located so the minimum service conductor clearance required by 230.9 and 230.24 can be maintained. Caution: The point of attachment for conductors might need to be raised so the overhead conductors will comply with the clearances from building openings required by 230.9 and from other areas by 230.24.

Multiconductor cables used for service drops must be attached to buildings or other structures by fittings identified for use with service conductors, and open conductors must be attached to fittings identified for use with service conductors or to noncombustible, nonabsorbent insulators securely attached to the building or other structure [230.27].

When the service mast is used as overhead conductor support, it must have adequate mechanical strength (or braces or guy wires to support it) to withstand the strain caused by the service-drop conductors [230.28]. Some local building codes require a minimum 2-in. rigid metal conduit for the service mast. In addition, many electric utilities contain specific requirements for the installation of the service mast.

Only electric utility service-drop conductors can be attached to a service mast [230.28]. Sections 810.12 and 820.44(C) specify that aerial cables for radio, TV, or CATV must not be attached to the electric service mast, and 810.12 prohibits antennas from being attached to the service mast. In addition, 800.133(B) and 830.133(B) prohibit broadband communications cables from being attached to raceways, including a service mast for power conductors.

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.