My rooftop antenna is begging to be replaced. The most serious problem is that the pole is rusted out, and looks like another big storm could snap the thing in two.
During a recent inspection, I couldn’t see any manner in which the whole antenna was grounded. I’m all set to install a new pole and antenna, but the instructions I have in my hot little hands basically says, “Ground the antenna in the same way that your old antenna was.” Gee, thanks a lot.
I’ve tried googling to get some specific directions, but all I can find are pages trying to sell me Dish Network satellite dishes and such. The only thing I’ve been able to gather is that I can do it with a grounding stake, or by attaching the antenna to some other type of fixture – I think they mean a cold water pipe, but I’m not sure – and it’s not clear how to go about doing any of this.
Can anyone point me to some simple, step by step directions on how to ground a rooftop TV antenna?
Check out the bottom of this page where it says “Grounding Outdoor Antennas” and “The NEC Requirement.” That explains the basics quite nicely. Ground rods, if you need one, are available at Home Depot, Lowe’s, etc. They’re copper-clad steel rods (copper for conductivity, steel to withstand being pounded 8-10 feet into the ground with a sledgehammer.)
I would suggest you go by your local Radio Shack or equivalent. They should have a grounding kit, which consists of a heavy bare aluminum wire and a clamp. They should also have instructions on the correct installation. I got mine secondhand, so I used the ground that the cable guy prepared (I no longer have cable.) One end of the wire is grounded to a pipe with the paint scratched off to make an electrical connection. The other end is attached to the base of the pole.
Your dish itself may not be grounded, but if the support structure is metal then that should be grounded and the shield on the cable should be also.
Follow the directions in the second post and make sure that everything that you ground in your system is at the same ground potential. Don’t drive a seperate ground rod for your antenna unless you intend to connect it (the new ground rod) to the ground rods for your electrical service too.
I don’t know much about antenna installations. But it’s my understanding that the antenna structure (mast, etc.) should be grounded for two reasons:
Lightning protection.
Basic electrical safety. If a 120 V “hot” wire comes in contact with your antenna, you want to make sure the circuit breaker trips.
Your ground connection(s) should address #1 and #2.
To address #1, it is best to drive a copper rod into the ground as close as you can to where the antenna is installed. You then want to connect a short and heavy conductor (aluminum?) between the antenna and rod.
But you can’t stop there. Why? Because such an arrangement does not address #2; if a 120 V “hot” wire comes in contact with your antenna, the circuit breaker may not trip.
To ensure the circuit breaker trips in the event of a ground fault, there needs to be a low-impedance path between the antenna and the neutral/ground bus bar in your circuit breaker box. This could be done two ways:
a. Connect another ground wire to the antenna, and connect the other end to the neutral/ground bus bar in your circuit breaker box. (Alternatively I suppose you could connect to the ground wire in the closest receptacle. But I’m not sure if that would be kosher from the NEC’s point of view.)
b. Connect another ground wire to the copper rod, and connect the other end to the neutral/ground bus bar in your circuit breaker box.
(Of course, I suppose you could also connect the grounding cable between the antenna and the copper rod used by your breaker box. This would take care of #1 and #2 at the same time. But if the copper rod used by your breaker box is far from your antenna, you may want the antenna to have its own rod as described above.)
Again, I don’t know much about antenna installations, so I could be wrong about some of these things. But I really can’t see anything wrong with the above-described arrangement.
I’ve installed a number of TV antennas and never (repeat) never grounded a single one of them. TV service for many years.
Just think of it this way.
Lightning is “looking” for the easiest path to ground.
Why should you be the one provide it with one?
Your elecrtonic equipment are already equipped with lightning protection in their antenna circuits.
Back in the 30s the countryside was crawling with lightning rod salesmen. Don’t see many now a days do you?
Of course some people still swear by snake oil.
Because if it’s raining everything is wet. Lightning is very unpredictable with regards to the path(s) it takes. It’s primary target may not be your antenna but the tree very close to it, the service mast, the chimney, ect. Even if there is a small path to ground with regards to the way the mast or antenna is supported, the lightning has a good chance of finding it. If it finds it it can route itself through material that is not intended to carry current and may start a fire or in the least, damage a bunch of stuff.
Wouldn’t this be a direct link from the antenna to the TV?
Besides, how many people put surge protectors on their cable/antenna lines going to the TV? I would think you’d want to divert as much of the discharge to the safest point of ground in the system as possible.
NEC 2005 edition-Article 810 Radio & TV Equipment
810.21 Grounding Conductors
(A) Material. The grounding conductor shall be of copper, aluminum, copper-clad steel, bronze, or similar corrosion-resistant material. Aluminum or copper-clad aluminum grounding conductors shall not be used where in direct contact with masonry or the earth or where subject to corrosive conditions. Where used outside, aluminum or copper clad aluminum shall not be installed within 450 mm (18") of the earth.
(F) Electrode. The grounding conductor shall be connected as follows:
(1) To the nearest accessible location on the following:
a. The building or structure grounding electrode system as covered in 250.50
b. The grounded interior metal water piping systems, within 1.52 m (5 ft) from its point of entrance to the building, as covered in 250.52
c. The power service accessable means external to the building, as covered in 250.94
d. The metallic power service raceway
e. The service equipment enclosure, or
f. The grounding electrode conductor or the grounding electrode conductor metal enclosures
(H) Size. The grounding conductor shall not be smaller than 10 AWG copper, 8 AWG aluminum, or 17 AWG copper-clad steel or bronze.
(J) Bonding of Electrodes. A bonding jumper not smaller than 6 AWG copper or equivalent shall be connected between the radio and television equipment grounding electrode and the power grounding electrode system at the building or structure served where separate electrodes are used.
Without all of the extra typing, the conductor must be supported, protected from physical damage, if run in a metallic raceway, that must be bonded also, must be run in a straight line, can be inside or outside, is not required to have insulation, and connections must comply with 250.70
Might work the way you have planned.
But as you say lightning is unpredictable.
As I said above “why should you provide a path?”
Unless of course you strap a 1 iron to the antenna.
I do. I surge-protect the crap out of everything, including cable TV lines. I live in west central Florida, a.k.a. the Lightning Belt. And despite near-daily thunderstorms, the occasional hurricane, and many power interruptions, brownouts and spikes, I have yet to lose anything to lightning or related power nastiness. Those little $10 cable TV surge protectors at Radio Shack are cheap insurance, and apparently work quite well.
