Lightning protection for wireless network camera?

[jrowell 0]

I will be installing a wireless camera soon, outdoors in a lightning prone area. It's at a resort in the forest at the edge of a lake, and they get a lot of lightning there. The plan is to mount the camera on the side of a tree. It's a wireless cam so there will be no signal cable for lightning to travel down. But there will be a power cable.

 

I envision running the power cable down the side of the tree through conduit that would then run under the ground to the nearest electrical hookup. My concern is protecting the camera from a lightning strike, and also keeping the lightning from running down the power cable.

 

Would it be best to use a plastic housing for the camera and PVC conduit for the power cable? Or would metal be better? Is there a device I should place in the electrical cable to keep lightning from entering the power line? Would I need a good earth ground? Or should I even be concerned, seeing it would be just a small camera mounted on the side of a tall tree? I'm really a noob when it comes to lightning, so I'd appreciate any advice. Thanks!

[VST_Man 1]

use plastic & PVC as the metal will conduct lightining strikes. Insulate EVERYTHING you cab from the tree itself.............you should be fine.

 

My first TREE install I mounted the domes on the trees and guess what, lighting got them and the DVR....so, I mounted plastic 4x4x3 boxes on the trees first and then mounted the cameras to them, using the inside of the box itself for the wiring.....and added BNC lighting protection at the DVR....since then no problems at all.

 

Since you are wireless all you need is a surge at the plug end of the power for the camera.................

 

oh, and keep your camera under and lower than anything else..........

[Rooney 0]

use plastic & PVC as the metal will conduct lightining strikes. Insulate EVERYTHING you cab from the tree itself.............you should be fine.

 

My first TREE install I mounted the domes on the trees and guess what, lighting got them and the DVR....so, I mounted plastic 4x4x3 boxes on the trees first and then mounted the cameras to them, using the inside of the box itself for the wiring.....and added BNC lighting protection at the DVR....since then no problems at all.

 

Since you are wireless all you need is a surge at the plug end of the power for the camera.................

 

oh, and keep your camera under and lower than anything else..........

 

Isolating the cable in plastic conduit is absolutely the WORSE thing you can do. That only gives the current one thing to travel through, the cable. Lightning protection is one of the areas that I am WELL versed in. Lightning protection is acheived by maintaining a low indifference to ground. Use a surge device at the camera with the surges ground bonded to the metal conduit. Also place surge protector at the other end bonded to the conduit. If the tree gets struck you want the energy to dissipate through the metal of the conduit or tree to find its path of least resistance. If you place the power cable in plastic it will run down the cable then jump out when it findes another path, thus you will have to replace the cable and plastic conduit every time. Not including the camera that can be damaged as well.

I also recommend a surge arrestor on the signal cable going to your antenna bonded to the conduit. If the camera and signal equipment is completely bonded to the ground the lightning has a greater chance of not seeing it and traveling through the tree. When you have something that stands out from the surrounding area there is more of a chance it will get hit. Another good piece of advise is the fact that most of the electrical buildup of energy before the lightning forms is around 30-45 feet in the air.

[vin2install 0]

BONDING very important. As there is no guarantee against lightning strikes.

[wisp_engineer 0]

If the lightning is as bad as you say it is...

 

You are going to have a lot of money and work involved.

 

 

 

How far away is the electrical feed?

[VST_Man 1]

I disagree................and have learned the hard way via replacing damaged equipment..................

 

if the tree gets struck or is close by a strike the energy is not likely to travel thru any of the CCTV equipment since it is isolated. metal conduit attached to the tree provides that path and guess what is inside that conduit? CCTV cable........nuff said.

 

lightining is a strange animal that can be anticipated but never conquered...........

 

and, the possibilities of the cable getting a direct hit is low in my opinion. the energy we neeeeeeeeeworry about is the tree hit and what that energy does after it is hit. think of it this way; a tree a tree makes a pretty good lightining rod......anything attached to it will feel a strike. isolating will reduce the effects.

[wisp_engineer 0]

Well the tree might offer the lowest potential so it may bear the brunt but with lightning you have to also remember there are after-effects like residual electrical discharge and resonance that must be dealt with.

 

 

Ever see a communications tower grounding system? They have the halo at odd path lengths and bonded certain ways for a reason. Those odd/even lengths average out to produce a grounding system that ensures that after the strike the left over energy is dissipated properly without causing damage to sensitive equipment.

[atropine 0]

I disagree................and have learned the hard way via replacing damaged equipment..................

 

if the tree gets struck or is close by a strike the energy is not likely to travel thru any of the CCTV equipment since it is isolated. metal conduit attached to the tree provides that path and guess what is inside that conduit? CCTV cable........nuff said.

l

 

Air is an insulator though remember, and plenty of people standing under tree's have been killed/injured when the lighening hits the tree passes down through the tree, but arc's out of the tree at the level of the person's head because the person has less resistance than the tree. The lightning than passes through the person to ground, or more likely to the person's feet where the lightning once again arc's to ground due to the insulation provided by a person's rubber shoe sole.

 

I just don't think a plastic box for your camera or conduit for the wiring will protect it from lightning arc'ing across from the tree, as copper wire is a far superior passage to earth.

 

I'm about to do a tree install, I was just going to put a thick earth cable up the opposite side of the tree trunk, and run it about 4feet higher up the tree than my camera. The cable earthed with a earthling peg at the base of the tree.

 

I didn't use a lightning conductor as I don't' actually want to be attracting lightning so close to my camera, but I figured if it was going to hit the tree anyway it would then run along the earth cable to ground and not hurt my camera or DVR.

 

If this doesn't sound logical/ok then maybe someone can say.

[jrowell 0]

I'm about to do a tree install, I was just going to put a thick earth cable up the opposite side of the tree trunk, and run it about 4feet higher up the tree than my camera. The cable earthed with a earthling peg at the base of the tree.

 

Based on the responses so far, I was starting to think along the same lines myself. It seems very unlikely to me that lightning would hit the camera directly, most probably it would hit the tree first and then arc over to it. So if I enclose the camera and cable in plastic and then run an earth cable up the opposite side of the tree as atropine is considering, it should direct the lightning safely to ground while keeping it far from the camera, right? In case it helps I'm planning on placing the camera about 15 feet up, and the tree is much taller than that. It's a wireless cam with built-in antenna, so no data cables to worry about.

 

VTS_Man and Rooney care to weigh in on this idea?

 

Thanks to each of you for your thoughts so far, I'm learning a lot already.

[Rooney 0]

I agree that having a good grounding on the opposite side of the tree would help. The main thing with lightning is to bond everything. It is true that lightning travels to the path of least resistance, but, the reason lightning strikes something in the first place is because it "see's" a path. That is why when you bond (tie everything electrically) everything together the bonded system appears to the lightning to be the same as the surrounding area. Thus making the chance that lightning will hit what your protecting the same as the chance of lightning hitting anything around it. Nothing is 100% but a well bonded system has the same chance as whatever is around it. So the odds of it hitting the equipment is much less then having that seperate "view" for the lightning. Living here in Arizona we have monsoon season that is very lightning rich. With the fact that thier is also alot of copper in the ground, we have many strikes. I have installed cameras on poles that are at the most vulnerable height (30-45ft.). The cameras the client previously insalled got fried every monsoon at least twice. He called me and I installed the cameras and bonded everything in metal conduit with surge arrestors and a ground rod at the base of the poles. After all of the bonding and arrestors installed, the pole actually never got hit again (6 years now). It may sound like putting the metal conduit and ground rod in makes it a lightning magnet, but, the exact opposite is true. The lightning now doesn't even see the pole because it matches the surrounding areas electrical potential.

 

I hope that helps your decision. Good luck.