Does effective lightning protection for cat5 exist?

Discussion in 'Networking' started by erkme73, Jul 1, 2019.

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  1. erkme73

    erkme73 Getting comfortable

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    After suffering my first significant lighting strike damage last week, I've been doing some research trying to find a way to minimize my exposure to a repeat of what happened.

    I have cameras and switches spread out over large areas, with many 500'+ runs between locations.

    From my home, I have a 300' run to my barn switch. From the barn switch, I have a 500' run to my gate opener switch. From my gate opener switch, I have two 500' runs to PTZ cameras mounted 20' up on utility poles.

    There is AC at all switches.

    All cables are unshielded, pure-copper, 23AWG, gel-filled buried cat5e.

    When the lightning struck near the furthest PoE+ PTZ camera, it made it all the way to the house, killing numerous switches, cameras, and cables. Surprisingly, some of the closest cameras survived unscathed.

    In any case, at this point I have to replace one of the 500' runs on at the street due to the damage, and I'm stymied on what technology to use that would not only reduce the odds of this type of systemic damage, but is also affordable, and easy to implement within the space constraints of the weatherproof boxes I currently have.

    Does anyone have any advice on how to secure my installation? I live in middle-TN where storms often include some pretty intense lightning. This installation has been in for almost 2 years, and this was the first hit.
     
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  2. TonyR

    TonyR IPCT Contributor

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    Check out how Ubqiuiti deploys PtMP (Point to Multi-point) ==>> here.

    In their image below, just replace the 'Computer' in each of the 5 houses with your IP camera, also with a unique static IP in the same subnet of 192.168.1.X, outside of the router's DHCP pool.

    If the IP cam locations demand it, make the home-base antenna omni-directional. I would probably use 5 GHz (NSM5) radios but a site spectrum survey would be wise.

    airMAX-How-to-Configure-a-PtP-ISP-Style-AP_Diagram.png
     
  3. erkme73

    erkme73 Getting comfortable

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    Intriguing. But, part of my dilemma is that each of the camera locations - particularly along the street perimeter - have no AC. They all get fed by the PoE+ switch at the gate. From there, it's several 500' lengths. To divorce the camera locations from a physical connection to the switch, I'd need AC at each point to power the remote radios, no?
     
  4. CCTVCam

    CCTVCam Pulling my weight

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  5. TonyR

    TonyR IPCT Contributor

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    Yep. Unfortunate.
     
  6. erkme73

    erkme73 Getting comfortable

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    Well, unless there's a more cost-effective solution, I suppose I'll just have to live with the risk. I did buy some surge suppressors from Ubiquity. They're sacrificial, and only run about $12/each. I'll put those at both ends of the long runs between the road/barn/house. At least that way, the damage might be limited to just a section.

    Incidentally, after inspecting the 150m line between the gate PoE+ switch and the zapped Dahua PTZ (story in original post link) I found lightning damage about half way down the line. The copper wire was pink and melted at the end...

    upload_2019-7-2_9-18-44.png

    This cable was never buried, making the failure location process pretty easy. However, I did find several smaller holes through the exterior jacket, the interior jacket, and I could see gel-coated bare copper on at least one of the conductors. At first I thought these may have been exit points from the lightning strike. But, upon closer inspection, it appears to be rodent chewing activity. Since the line is always energized, I'm sure they get one good bite, and move on. And with the gel, the conductor is still protected from weathering/oxidation.

    No doubt, the entire line will be replaced (1000' reel on order). But now I'm torn about leaving cable above ground. I like laying eyes on it, but I don't like squirrels and rats having access either. First world problems...
     
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  7. cage771

    cage771 Getting the hang of it

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  8. iseeker

    iseeker Getting the hang of it

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    For these to be effective do I need to use shielded cable and plugs or does this function right with just normal UTP CMR cable? Does it matter where you put them (near camera or further away)? I'm running 4-5 lines outside and don't want to buy one of these for each ($$s), but will if I need to (recently had lightening strike at home). Could I put a sacrificial, POE switch in the attic, then put the DITEK between the switch and the patch panel and interior switch? Would lose the POE switch in a strike, but wouldn't have to buy 4 of these bad boys.