A general overview, not a code book. This guide summarizes federal safety advice and one published summary of the National Electrical Code. Building and electrical codes are adopted locally, and the edition and any local changes vary. Check with your local building department before you install, and hire a licensed electrician or installer if you are unsure about any step.
Power lines come first
Overhead power lines are the main danger in an antenna install. The Consumer Product Safety Commission reported that between 1990 and 1998, more than 300 people in the U.S. were electrocuted, in a warning about overhead power lines (CPSC). Its advice:
- Keep the distance from the antenna or pole to the power line at least 1½ times the height of the antenna or pole.
- "Never place a ladder anywhere near an electrical power line."
- "Never assume that an overhead power line is electrically insulated." Treat every line as live.
CPSC's safety rule for CB base station antennas asks for even more room: at least twice the combined length of the antenna and mast from the nearest power line. It also requires this warning: "IF ANTENNA NEARS ANY OVERHEAD WIRES, IMMEDIATELY LET GO, STAY AWAY, AND CALL UTILITY COMPANY" (16 CFR 1204).
Ladders near power lines
OSHA's advice for workers applies at home too: "Keep all ladders and other tools at least 10 feet away from any power lines" (OSHA). OSHA's ladder card says to avoid using a metal ladder near power lines (OSHA QuickCard), and its training video adds that a ladder with non-conductive side rails "is safer but not a guarantee" (OSHA). If the only good spot is near a line, choose another spot or call a professional.
Grounding: what NEC Article 810 asks for
Article 810 of the National Electrical Code covers radio and TV antennas. Mike Holt summarizes its main requirements for outdoor TV antennas in EC&M (EC&M):
- Ground the mast. Outdoor masts and metal antenna structures must be grounded under section 810.21.
- Add a discharge unit. "Each lead-in conductor from an outdoor antenna must have a listed antenna discharge unit."
- Use heavy enough wire. The bonding conductor or grounding electrode conductor must "not be smaller than 10 AWG copper."
- Tie into the house ground. The conductor terminates at the building's intersystem bonding termination.
- Keep clear of power wiring. Antenna lead-in conductors must be at least 2 ft from exposed electric power conductors.
CPSC also tells consumers to ground masts according to code. Code editions and local amendments differ, so have an electrician or your building department confirm the details for your house.
Before you mount it
- Pick the spot from the ground. Look up and around for power lines before you carry anything up, and measure the distance against the antenna and mast height using CPSC's rule above.
- Know your direction. Your city page lists the compass direction to each tower, and our guide on how to aim a TV antenna covers fine-tuning.
- Check your rights and rules. If you rent or have an HOA, see our guide to antenna rules for renters and HOAs.
- Consider the attic. An attic antenna avoids the roof, if your signals are strong enough.