Question Isolate Outdoor From Indoor For Lightning

Nov 17, 2019
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Hopefully the sketch makes sense. I have some devices outside, cameras, etc. Some are POE since no power is close to them. I'd like to isolate them from the inside network to protect indoor devices from strikes that may hit the outdoor devices.

I've tried various wireless gizmos and none have worked reliably, if at all.

What should/could the two red ovals be? They might only need to be a couple of feet apart.

LAN.png
 

In2Photos

Golden Member
Mar 21, 2007
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You could use a media converter to convert to fiber at each oval. Then connect the two together with a fiber patch cable. Multi mode fiber would be the choice for short distances.
 
Nov 17, 2019
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I have an in-line surge protector at that point now:

8 port switch >> patch cord >> surge protector >> patch cord >> POE switch.

As started, run is about 3 feet, just through a concrete block wall, too close to warrant the cost of fiber and hardware unless it has come WAY down. I was hoping for some new type of wireless device that would be more dependable to pick up the signal off the router and convert to hardwire. I guess they used to call them access points or repeaters, or extenders, but nothing I've tried has been dependable
 

In2Photos

Golden Member
Mar 21, 2007
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I have an in-line surge protector at that point now:

8 port switch >> patch cord >> surge protector >> patch cord >> POE switch.

As started, run is about 3 feet, just through a concrete block wall, too close to warrant the cost of fiber and hardware unless it has come WAY down. I was hoping for some new type of wireless device that would be more dependable to pick up the signal off the router and convert to hardwire. I guess they used to call them access points or repeaters, or extenders, but nothing I've tried has been dependable
Media converters are less than $30/each and the patch cable is $15. Is that cheap enough?


 
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Fallen Kell

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Oct 9, 1999
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I know this is an older thread, but just wanted to chime in that from experience, you won't be able to isolate as much as you think running fibre to the outdoor switch because the power to the PoE switch is still connected to your house's panel and a lightning strike will easily travel back through that to your home and hit you panel and thus anything connected to the panel (yes, technically it should go to ground there, but it is such a high amount of surge that it still flow out to other devices and get to other grounds through them as well due to the enormity of the surge).

The only way to attempt to alleviate it would be to have a lightning strike rod and grounding system on your home/property and even that will only mitigate things.

Don't get me wrong, running fibre is still the right thing to do, as at least the surge is then not going directly into your other network gear and directly to your computers and other expensive electronics, possibly putting a little distance between them and where the surge will be coming from (and with extremely good surge protection, you might be able to mitigate some of it by having those devices ahead of your expensive electronics take the bulk of the hit/burn out and possibly break the connection the other devices). But don't really count of it if you suffer a direct hit, as nothing short of the lightning rods and grounding system can handle that kind of load in standard construction homes.
 
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Fallen Kell

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Oct 9, 1999
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Yes, exactly. The media converters and the PoE network switch need electricity. Which means there is a copper wire (in the form of a power cable) being run from from a outlet (outdoor outlet, covered outdoor outlet, or outdoor junction box) to the switch and media converter and the outlet has a copper wire connected to it which connects back to an electrical panel that is in the house, and that electrical panel connects to all the other circuits in your house or it connects to another panel which connects to all the other circuits in your house. In other words, there is a direct connection of a copper wire from all the outside cameras, to the PoE switch, and from the PoE switch to the house on which a lightning strike will traverse.

The only way that there is not such a connection back to your house is if you have a second power feed on your property such as a stand-alone generator or solar panels/battery system that powers the PoE network switch and all those other external devices.
 
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Nov 17, 2019
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Difference here being that AC devices and surge suppressors tend to be more robust and effective than those for communications cables and connections. Even with wireless, there is still a need for power at the distant end.
 

Fallen Kell

Diamond Member
Oct 9, 1999
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Difference here being that AC devices and surge suppressors tend to be more robust and effective than those for communications cables and connections. Even with wireless, there is still a need for power at the distant end.
Oh absolutely, no doubts about that. Most (good) equipment has some amount of design built-in for expecting a possible surge from the input power. Almost nothing has any kind of surge protections on a network line. But what I have been saying is that NONE of the surge protections that equipment has on the input power will protect it from a direct lightning strike. The kind and level of protection in the systems are basically able to help stop a damage from a lightning strike that hit power lines 4-5 miles away. But if it takes a direct hit at or near you, it will blow all the equipment. Heck people lose equipment all the time from a local transformer failing, and that amount of surge is only a tiny fraction of what a lightning strike can do. That is my point and that is what I have been talking about the last few posts.

Yes, use fibre, it is the best practice. But don't think that it will be able to protect you from a lightning strike. The only way to do that is to physically disconnect the connection to the external power circuit from your house or have it otherwise completely de-coupled from your power. And even then, your internal equipment is still extremely vulnerable during a storm unless you have a lightning rod and suppressor system installed on your home, because a strike hitting your home will travel down the electrical wires in the house, especially more modern houses which are using less and less copper and iron pipes in the plumbing...
 

fkoehler

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Feb 29, 2008
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Couple of things.

In talking about backups, I never hear anyone suggest grabbing a cheap blu-ray burner and getting all those family momentos on a few solid disks.

Fiber adapter is a good idea, I've installed hundreds of them in many locations and never had one go bad I think. Haven't used the really cheapo ones though.

Good primer for lightning.