Grounding?

[Trigger]

I've done a search and am more confused than ever.

I plan on putting a scanner antenna up and would like to confirm what I think I have read.

To ground my antenna, I should run a ground wire from the antenna to a ground rod about 2 ft away from the house. Then, run another ground wire from the ground rod to the service panel of the house. Is this correct? I understand that this is to provide two paths to discharge a lightening strike, yes?

Instead of grounding to the service panel, can I ground to say an outlet box, would that be the same?

Sorry to the neophite questions....

 

[ReceiverBeaver]

Hey guy,

Fine to think of grounding antennas but I just wouldn't bother with it at all. Your little antenna is no more of a lightning target or attractor than anything else around your property and otherwise would serve no benefit. It will not improve reception.

What you then do to protect your radio against an electrical hit is to simply disconnect the coax AND any home ac power source you may be using when a storm is around or you're away for awhile. Isolate the coax away from your radio & electronics when disconnected. I stick mine down in a gallon glass apple juice jug.

I have a 10' tall 2 meter (VHF) base verticle on my roof and I operate this way myself.

If you decided to ground, go to the rod in the ground only. You definately do not want to encourage lightning to go bouncing around into your house by connecting over to the house electrical ground anywhere. That's crazy talk.

Materials are at least a #6 solid copper wire to a standard 5/8 copper clad steel 8 foot grounding rod. Both are available at any large hardware or Lowe's ect.. At the top of course, connect wire near the lowest point on the metal mast pipe or mount you are using. Do not connect directly to the antenna.

Hope some of this helps, good luck

 

[N_Jay]

Hey Beave, you may want to do some checking before repeating Eddie's recommendations.:lol: :lol:

In many areas NEC (national electrical code) requires grounding.

NEC also requires that multiple grounds be connected.

There is lots out there on grounding. Not all of it agrees, but you should be OK following the recommendations of any authoritative source.

NEC
Motorola
PolyPhaser
etc.

 

[Trigger]

Thanks.

So do I have the general concept right according to the NEC? Antenna to ground rod, ground rod to house electric box?

 

[jim202]

It looks like there is someone on here that doesn't have a clue what to do
about lighnting protection.

Let me point out a more suttle reason for looking at the NEC and what it
says for grounding a communications antenna. The point is your house
insurance company. They have a real dim view of paying off on damages
from lightning if they can say the antenna system was not grounded properly.
Before you go ignoring grounding of an antenna system, best you ask your
insurance carrier what their requirements are.

Structure get hit all the time. Normally the lightning likes to hit the highest
object at the structure. If your antenna happens to be the tallest object, then
guess what.

I have been in the radio field for over 40 years now. About 15 of those
years were spent building cellular tower sites. If anyone ever tells you
that you can't survive a direct strike from lightning, tell them they are full
of ****. I have seen a number of the towers and mono poles take a direct
strike and the equipment keeps right on ticking. The tower or pole may
steam a little after the strike, but the radio gear and electronics stay
working.

The average house or commercial building doesn't have the surge and
ground protection that a cell sites has, so you can expect some damage
to take place. On the other hand, there are some measures you can take
to minimize the damage. The first step is a low resistance grounding system.
You notice I used the term system and not a single ground rod.

Jim

 

[Trigger]

Ok....so is there a recommendation on how to ground a scanner antenna out here somewhere?

I'm not any closer here to get an answer..... Are you guys telling me you don't know, don't want to say, or I have to pay someone to get the info?

Once more, do I run a ground from that mast to a ground rod and then run another wire from the ground rod to the electric box? Or am I completely off base? Clearly there is a prefered method but I haven't or at least understand what it is.

 

[prcguy]

NEC code is not for lightning protection, it’s for electrical safety. Most residential antennas cannot be grounded to survive a direct lightning hit, you would have to design the electrical system for this as you built the house. A single ground rod and a Polyphaser won’t save squat and there is a lot of bad and potentially dangerous advice floating around out here. With that said, for residential grounding of consumer TV, CB, HAM, satellite TV, etc, attached to your house, the NEC requires it to be grounded via a #10 or larger copper conductor to the nearest grounding point (breaker box, conduit that is grounded at the box, etc) not to exceed 20ft. Grounding to a separate ground rod only is not to code. The additional ground rod must be bonded to the house electrical ground similar to above but with at least a #6 copper wire and I forget the length for this one at the moment. I am not an electrician but am an SBCA certified antenna installer (and trainer!). Please check your local code for any additional grounding requirements.
prcguy

 

[Raccon]

If you decided to ground, go to the rod in the ground only. You definately do not want to encourage lightning to go bouncing around into your house by connecting over to the house electrical ground anywhere. That's crazy talk.

It ain't (see my response below) and may actually be required if the sources below are correct. In fact, simply put, all grounds should be connected together at some point.

To ground my antenna, I should run a ground wire from the antenna to a ground rod about 2 ft away from the house. Then, run another ground wire from the ground rod to the service panel of the house. Is this correct? I understand that this is to provide two paths to discharge a lightening strike, yes?

It's for equipotential bonding that avoids a current flowing between the two points, and it should be done between the rod and the existing main grounding bar of the house (which may or may not be located in the service panel). If you have different (electrical) potentials a current can flow, in case of a lightning it may flash over and leave it's designated path to ground.

Instead of grounding to the service panel, can I ground to say an outlet box, would that be the same?

You mean a (grounded) AC wall outlet? Then the answer is a clear no, the grounding in AC outlets is for the Protective Earth (PE), not for lighting protection. The wires of the PE are too small anyhow to carry the current of a lighting strike.

These picture may give you some ideas but I take no responsibility for their correctness:

Example of Antenna Grounding (Source)

The NEC requirement (Source)

I advise you however to have a professional do this for you, if done wrong you may increase the risk of a lightning strike rather than decrease it.

 

[Trigger]

Thanks Raccoon. Thats exactly what I was looking for.

 

[theo1972]

well if he decides to ground that yagi, or any antenna for any purpose, does he have to peel the sheathing off the coax coming from the antenna and attach the shield on coax to ground on mast or/and earth ground? more or less, do you ground the shield on coax cable.

 

[Sinister]

Please start a new thread with your question rather than bringing back a thread from 11/2006.