Ouch! Lightning fried my network

Modem, router, some Cat5 runs, and my beloved, never-failed-me C4 wiped out. Modem & router replaced, will tackle HE replacement soon with spare C4. This is the 2nd cable modem lost to lightning in 3 years, but the first time it has gone through the ethernet. (TP-link network switch still test Ok so far.) I do not have any POE but was looking at something like this Ethernet Surge Protector

I already have a 75 Ohm Lightning Surge Protector installed where the coax enters the distribution cabinet in the garage --obviously not doing a great job, but I could put a 2nd one immediately upstream of the cable modem.


My only contribution would be that my modem has died twice now, once being the modem inside my Netgear Nighthawk modem / router, where the router survived, and then a Netgear DM200 modem. So my only suggestion, for what it may be worth, would be, separate modem and router... Though I struggled to find a modem on it's own last time, getting a TP-Link modem / router....

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Yep, I'm already using separate modem (Arris) and router (Netgear).


I've nothing to contribute. Just wanted to say to say I am sorry to hear about the lightning strike and the equipment you've lost. I also live in a "lightning zone" and have similar surge protective equipment.


Yeah, it is not quite as bad as Florida here, but pretty close. I live between the 2 largest sound and estuary systems in the US and -though beautiful- they are excellent thunderstorm generators.

The big hits seem to be on the ISP's (Spectrum) buried network, not the house directly. They had some trouble restoring service this time.

I feel your pain. I've had lightning fry some of my HA gear at least five times, and it is because I ran cables to wired sensors through my attic years ago. I may as well have connected them to lightning rods on the roof.

I did put in diodes on those connections, which may have helped. But the main thing I'm doing is phasing out and isolating the wired sensor part of the stuff.

You may need a better ground path / more ground rods. There are ways to test for grounding, I have seen large electrical installations with ground grids / mats have issues with lightning strikes as well. It may be better to cut your losses and try and use a fiber to Ethernet converter to try and segregate your router from your modem.

If I had a dollar for every time I did that in industrial facilities, I would be rich. Sometimes it's faster to do an optical coupling than to argue with the electrical engineers on why the grounding's fubar - because they will argue for weeks on why the data shows it's just fine.

Yet magically, putting in the optical coupling fixes all of the surging and equipment death issues.. weird coincidence I guess... :wink:


Professional experience..... can't be true..... :wink:


Coming from the Generation/Transmission side of things fiber is a really easy solution to the problem sometimes.

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I owned an electrical wholesale company, so 5/8" x 8ft copper-clad ground rods at the service entrance and another one under the coax (and obsolete landline) comm cabinet. The water table here is about 24" below the surface --still, I'm considering another dedicated rod for the media cabinet (would be hell installing it in the crawlspace, but do-able).

Interestingly, my Square D "QO" series panelboards haven't tripped a breaker with these hits --another indicator that they're coming in on the coax.


Give me an Amazon link or it won't happen, heh!

Just need a boring old pair of media converters in most cases.

These aren't the exact ones I'm using at home, but similar.

Then just buy a short single mode or multimode fiber (depending on the media converter optics) to connect between them. I plug the media converters into 2 different outlet strips - not that that is required or anything, but I figure 2x electrical surge is better than 1x.

Most media converters are just dumb passthrough devices, so there is no configuration or anything needed. As long as you get link lights when you plug in the fiber you're done.


I have a discone antenna on my roof for my Home Patrol II scanner. My research showed a lightning arrestor with a gas discharge tube is the best. Lots of talk on the antenna forums about the cheap non discharge tube arrestors. Most people think they are junk.

My discharge tube arrestor has 50 ohm SO239 connectors, but they are available with 75 ohm F connectors also.

Here is one example :

If and when a lightning strike happens, the tube can be easily replaced.

The arrestor needs to have someplace to discharge so I have a copper clad rod driven 8 feet into the ground right at the house. Best practice is to use 2 ground rods spaced about 8 feet apart.

Was this covered by insurance?


Off topic - The one I learned the hard way is that sometimes welders really like to just connect their ground wherever they want (even where they are explicitly not supposed to connect...)...

No matter how well your grounding bus is designed, that does bad things to sensitive equipment. :wink:

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No. I'd rather take a lightning hit to my forehead than deal with @!@#$ insurance agents.

Off topic - I generally self-insure up to $100k. I'm waaaaay ahead of the game so the 'reserve' covers this easily.


Like so?


Be careful, the term "single point ground" is very important. If a lightning strike finds a path between 2 grounds that are not bonded together properly, it is going to take it. House neutral comes to mind. Look up construction codes beforehand.

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The ring terminal crimp connector for the ground wire the gas tube arrestor I have only accepts 18 gauge wire or smaller. Used an automotive crimp connector that accepts 10 gauge wire but with the right size ring terminal. Not saying the engineers didn’t know what they were doing but ‘bigger is better’

Edit : this model accepts 10 gauge wire

Another unbiased opinion :


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