Outdoor PoE Equipment? Don't forget surge suppression...

[ForkWNY]

Spring brings stormy weather, and it's around the corner. Not sure if others have posted about this, I didn't see much in the way regarding PoE surge protection in the forums, but can't hurt to have this info repeated nonetheless, especially because outdoor PoE devices are becoming more popular and widely-used.

If you have outdoor PoE equipment, or outdoor ethernet devices in general, surge suppression is absolutely necessary. I recently installed an outdoor PoE powered EAP, and hadn't given surge protection much thought, but after reading a number of horror stories, I ended up installing one inline between the Outdoor EAP and my PoE switch. It's a CITEL MJ8-POE-A, runs about $30 on Amazon. It has a 16kVA discharge rating, other devices have much higher discharge ratings, but figured it's better than nothing. I made a DIY ground wire which is connected to the main ground in my 200A circuit breaker panel.

Some damage photos I found from those who were unfortunate...

So post links/photos of PoE surge protectors you might already be using, and whether or not they have been put to the test, actually protecting equipment from genuine electrical surges.

 

[Tech9]

surge suppression is absolutely necessary

It only gives you a chance. When a lightning strikes with 300million volts you may not even find this $30 Amazon surge protector after.

 

[ForkWNY]

It only gives you a chance. When a lightning strikes with 300million volts you may not even find this $30 Amazon surge protector after.

You just have to hope the surge is stopped quickly enough and those gas discharge tubes do their job...as well as the avalanche diodes clamping down, breaking the circuit promptly enough to prevent further damage. I've observed surge protectors do their job well, while others seemed to do very little.

 

[Tech9]

I had equipment loss through much more expensive commercial ABB surge protectors. They were blown along with Panasonic phone switching system, 16-port network switch, two HP computer work stations and miraculously one server network interface only with surviving motherboard. I don't know where exactly the lightning hit, but the surge protectors were vaporized and the electricity hit the network through few centimeters wide air gap.

 

[tgl]

It's all about improving your odds. If a lightning bolt hits the power pole just outside your house, there's probably not going to be much left of your electronics no matter what protection you've put in. If the same bolt hits a block or two away, good surge protectors might save your stuff. There's a significantly larger chance of a nearby strike than a point-blank strike, so ...

Personally, I lost gear several times back in the eighties and nineties. I had a whole-house surge protector put into my meter box sometime in the early 2000s, and I've lost nothing since then. Maybe it's just luck, but I don't think so.

 

[To the ocean]

after reading a number of horror stories

why would this happen? won't it happen with indoor PoE devices?

 

[tgl]

why would this happen? won't it happen with indoor PoE devices?

I don't see any reason to think that "outdoor" has much to do with surge hazards (unless you plan to mount your security cam on a lightning rod ), nor does "PoE". What an outdoor device is at extra hazard from is plain old ground-fault shorts, if you don't use proper wiring methods.

 

[Cake]

I would not expect anything to survive with a direct hit, but I assume OP is talking about induction from a nearby strike? I have some POE Ethernet to run soon outdoors and I live in a area that gets blasted for 4 months straight of near daily storms. The OPs picture had a black cat 5e wire nearby. I assume its not shielded? I am thinking about running only shielded CAT 6 (not going to ground the shield though) on all my runs. I had a cheap patch cord on two different desktop computers and ended up with a non working interface which meant main boards. This is good topic.

 

[degrub]

If you want to avoid most electrical issues, run a fiber optic cable, either as an aerial or in plastic conduit about 12 inch below the surface. Anchor and strip back the support wire before entry to the building.
No earthing loops and no induced noise/impulse on the fiber from sheet current across the soil and structure surfaces. Ground potential will still elevate, but the diodes in your power supplies will resist some of it unless the strike is very close. Proper earthing and use of lightning protection aerials can help manage the high current during a strike. Benjamin Franklin's system worked to reduce damage from strikes on church steeples several hundred years ago and continues to work today.