Code Q&A

Dec 22, 2005 5:14 PM, By Mike Holt

Q. What are the NEC grounding requirements for a satellite dish?

A. The metal mast [810.15] for radio and television equipment and its lead-in cable via a discharge unit [810.20] must be grounded to the building grounding electrode system in accordance with the requirements of 810.21.

Grounding of the metal mast and lead-in antenna cable serves to reduce voltage surges (caused by static discharge or nearby lightning strikes) from reaching the center conductor of the lead-in coaxial cable. Because the satellite sits outdoors, wind creates a static charge on the antenna as well as on the cable attached to it. This charge can build up on both the antenna and cable until it jumps across an air space, often passing through the electronics inside the low-noise block filter (LNBF) or receiver.