Grounding a Television or Communications Antenna
How to Install an Earth Grounding and Bond for Communication Antenna: Guide for Grounding an Antenna System© By: Dave Rongey
Guide for Grounding an Antenna System
Electrical Question: I would like to install a small outdoor television antenna (side of the house, not the roof), and I’d like to be sure it’s sufficiently grounded.
- I realize that according to code, I should ideally have an 8′ steel, copper clad grounding rod, but I don’t think I can go that deep, and I don’t know where to buy such a rod.
- I was told at a reputable hardware store that 6′ of copper tubing was sufficient – is this true?
- I also realize that ideally I should ground the antenna to the main service ground, but in my case this would be a rather convoluted arrangement. So, what I have is a 3’4″ copper tube which I was able to get about 4’6″ into the ground.
- Will that suffice? Or am I putting my home and equipment at undue risk?
This electrical wiring question came from: Udayan, a Homeowner from Montreal, Quebec, Canada
Additional Comments: Great site – thanks.
Thanks for your electrical wiring question Udayan.
Yes, you are correct, your antenna should be grounded, however lets take a look at the correct and acceptable methods so we make sure this is done right:
- Earth Grounding for Electrical Systems
Earth grounding is the connection to earth through a ground connection or connections of sufficiently low impedance to prevent the destruction of electrical components, as well as electric shock that can occur from voltage from lightning, voltage transients, and contact with higher voltage systems. The earth grounding helps prevent the build-up of static charges on equipment and material as well as establishing a zero voltage reference point to ensure the proper performance of sensitive electronic and communications systems equipment.
How to Install an Earth Grounding and Bond for Communication Antenna
NEC, National Electrical Code references shown below.
The National Electrical Code required earth grounding of telecommunications NEC 800-40(b), antennas and lead-in cables NEC 810-21(f), CATV NEC 820-40(b), and network-powered broadband communications systems NEC 830-40(b). This is accomplished by bonding the communications systems to the building earth ground.
The Communications Systems must be bonded to any of the following Earth Ground Locations
- Building or structure grounding electrode system as described in Section 250-50.
- Interior metal water pipe meeting the requirements of Section 250-104(a). The limitation of 5 feet in Section 250-50 does not apply.
- Metal service raceway. (metal conduit)
- Service equipment enclosure.(electrical panel)
- Building or structure grounding electrode conductor.
- Metal enclosure enclosing the building or structure grounding electrode conductor.
- Accessible bonding means such as six inches of No. 6 copper conductor connected to the service equipment or raceway [250-92(b)].
When an electrode such as a ground rod is installed for the communications systems, it must be bonded with a No. 6 copper or larger bare or insulated conductor to the grounding electrode system at the building or structure served.
- Ground Wire Connection
Earth grounding termination to the grounding electrode must be done by listed clamp.
- Proper grounding of antenna mast and lead-in cables is somewhat effective in protecting receiving equipment from voltage surges, as well as voltage transients that result from lightning.
- The Antenna Mast
The metal structure that supports radio, HAM, television and satellite receiving antennas must be grounded to an acceptable earth ground [810-15] with a No. 10 copper bare or insulated conductor run in as straight a line as practicable [810-21].
- If the mast is not properly grounded, the Low Noise Block (LNB), as well as the dc rotor motors that control the positioning larger satellite dishes often will be destroyed by voltage surges caused by nearby lightning strikes.
- The Lead-in Cable
Each conductor (coaxial, control, and signal conductors) of a lead-in from an “outdoor antenna” must be provided with a listed antenna discharge unit (grounding terminal block).
- The antenna discharge unit must be located outside or inside as near as practicable to the entrance of the conductors to the building and it must not be located near combustible material [810-20].
- The discharge unit must be grounded to an acceptable earth ground [810-21(f)] with a No. 10 copper bare or insulated conductor run in as straight a line as practicable [810-21].
- If each conductor of a lead-in from an outdoor antenna is not properly earth grounded, the receiver can be destroyed by voltage surges caused by nearby lightning strikes.
When an electrode such as a ground rod is installed for the communications systems, it must be bonded with a No. 6 copper bare or insulated conductor to the grounding electrode system at the building or structure served. (this refers to the main electrical panel)
Do not install a separate ground rod if the antenna is mounted on the house structure.
As you can see, it is highly recommended to install the ground wire to the main electrical panel where it may be bonded with the main electrical ground system which will provide maximum protection and functionality.
If it is possible, locate the antenna near the electrical panel and install the antenna cable from that point to the desired locations.
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