Site grounding

[rebelwireless]

You still need to ground everything correctly, the fiber does absolutely nothing to protect your tower side gear. fiber does isolate your ground-level gear though, which is an obvious bonus.

[now]

Do you use shielded #2 to go up the tower or bare? and how do you normally attach it to a tower?
If its #2 bare and lets say its going up a silo do you try to touch it to as much metal as possible? Like the cage and maybe railing?

[sirhc]

Does you use shielded #2 to go up the tower or bare? and how do you normally attach it to a tower?
If its #2 bare and lets say its going up a silo do you try to touch it to as much metal as possible? Like the cage and maybe railing?

I run #2 Green which has an insulation.

I run #2 Tin when burring it.

http://www.sitepro1.com/store/cart.php? ... _list&c=17

Normally youe ground system is insulated from tower except when you attach it to antennas and antenna mounts. Your not trying to pick up charges from the tower your trying to provide a better path from your equipment than the Ethernet cable.

[wisp-wand]

Hi Chris, I would be interested in your opinion on this scenario.
We are on a water tower. it is made of reinforced concrete. We have our PSU at the bottom, where we pick up the mains and convert to 24vdc. We then have 1 pair thick gauge cable that cabled internally takes the DC 20 meters to the roof where our switch, and AP's are.On the roof there is a lightening conductor which is an aluminium strip. this runs around the top of the concrete tower, and anything metal such as ours and another colocated TV relay pole brackets are grounded to that bracket. The earth lug where available (EG on AF5X) have a 6mm earth cable that goes to the metal bracket. The lightning conductor runs down the outside, the full length of the tower to ground where there is a dedicated earth rod setup.

It seems to work ok and has survived 2 x summers with thunder storms etc no trouble, only recently has something started to occur, along with your post about grounding that has lead to think there maybe an issue.

Regards

Wayne

[sirhc]

Wayne can you post a few pictures of the site and the existing grounding system?

[chiefbmr]

What about a tower with no electric service? Solar/battery setup with a POE switch at the bottom and Cat5 up the tower.

Other than not bonding to electrical system, does anything else change?

And are there any advantages/disadvantages for a setup like this?


And what about taking the opposite approach. I have always wondered if the batteries, solar panels, cat5, antennas and radios were completely insulated from any ground source, would this be a better option than the ground and more ground way you describe? I know lightning can hit planes, but does anything get fried?

[chiefbmr]

I don't see any mention of having a lightning rod above all the equipment. Would this be beneficial? If so, would you run copper to the rod?

[rebelwireless]

If I'm getting this right, the only ground is this metal strap around the outside of water tower? How is your equipment mounted? Are you sure the strap is big enough to provide adequate ground? Is there a lightning rod? If so is it attached to this grounding strap and if not...then that grounding strap is likely going to take a hit. I wouldn't want my AF grounded to that...

On radios that have a dedicated ground, you should have a dedicated ground wire run down. Antennas grounded to the structure and the radio with to a separate dedicated ground wire. I'm assuming that 24v source from ground level is run up to a Netonix WS? So then the Netonix should be on that dedicated ground too.

Do you feed data up or is the top isolated (ie wireless backhaul)?

[gripper]

So...I'd like to put a WS in a tower site where I have great grounding. Currently, almost all radios are going through Atelicon/Hyperlink lightning arrestors just off the base of the tower, which I've never been wild about--I think they've caused me more trouble than they've avoided. From there we have a 50' run underground through pretty packed conduit to an cabinet inside conditioned space. Most of the radios are grounded to the tower itself, all three legs of which are explosive welded to a buried ring, #2 stranded copper IIRC. Per your advice, Chris, I'm considering eliminating the lightning arrestors. I think I would run green stranded copper up one tower leg and connect directly to all the radio grounds first, but I can't even think about trying to recable the cat5/6 from the cabinet to the radios on the tower for a continuous run. So the question is how to splice or otherwise connect the CAT for a minimum of insertion loss. Or do you think this is worth it at all?

[sirhc]

So...I'd like to put a WS in a tower site where I have great grounding. Currently, almost all radios are going through Atelicon/Hyperlink lightning arrestors just off the base of the tower, which I've never been wild about--I think they've caused me more trouble than they've avoided. From there we have a 50' run underground through pretty packed conduit to an cabinet inside conditioned space. Most of the radios are grounded to the tower itself, all three legs of which are explosive welded to a buried ring, #2 stranded copper IIRC. Per your advice, Chris, I'm considering eliminating the lightning arrestors. I think I would run green stranded copper up one tower leg and connect directly to all the radio grounds first, but I can't even think about trying to recable the cat5/6 from the cabinet to the radios on the tower for a continuous run. So the question is how to splice or otherwise connect the CAT for a minimum of insertion loss. Or do you think this is worth it at all?

So you're saying the tower is 50' away from your equipment?

This is BAD as the building where the equipment is probably has a DIFFERENT Earth Ground.

Grounding radios to towers is NOT a grounding system. Steel is a much higher resistance than copper so any stray current, static charge, or ESD charge will take the nice copper Ethernet cable instead.

Yes there should be a MAIN ground bus on insulators at the base of the tower that is connected to all the ground rods or halo system for the tower. As well the tower should be connected to the ground rods as well but but to your bus which is insulated. You always insulate your grounding system except where it bonds to the antennas as you do not want to drain the tower in the middle of charge but rather hope that charge follows the steel down as much as possible so as not to overwhelm your ground path. You only want to drain the steel at your antennas. You're hoping charge in the middle will go down the tower instead of up and then into your ground wire as the tower legs are also bonded to the ground rods..

There should be a BOND wire between the tower ground system from this main bus to the service ground rods and a ground bus in your cabinet but since this is 50' away it should almost be #1 gauge wire which is 1" thick.

There should be a #2 green running up the tower to an insulated ground bus near your antennas and a #6 from that bus to each antenna/radio.

You want to make sure you have ample Ethernet Service loops so your Ethernet path is at least 10% longer than the intended ground path.

You need understand that ground potential differences is just as dangerous to your equipment as ESD and Static discharges.


Follow the guidelines in these posts (Read these posts several times):
viewtopic.php?f=30&t=1816
viewtopic.php?f=30&t=188
viewtopic.php?f=30&t=1429
viewtopic.php?f=17&t=1786&start=30#p13447

The idea is that all equipment is within 5 ohms of each other as far as ground potential and no matter where there is stray voltage or CURRENT that the intended path is shorter and less resistive than the Ethernet cables.