Lightning and Ethernet

Found an article I read a while ago and thought I would share it. Based on this I’ve been using medical grade Ethernet isolators (IEC 60601 compliant) for surge protection inside, not for better sound.

Important to note that the article is discussing developing research so I wouldn’t say anything is fully settled yet.

Part of why I’m paranoid is that I have almost all of my expensive gear in the house hard-wired to copper based Ethernet:

  • TV
  • HT Receiver
  • Roon end point
  • 2 PCs
  • BD Player

So if a surge travelled down the Ethernet into my gear it would do a lot of damage, even if that damage was relatively lite, like taking out the Ethernet ports.


Fiber to the house can be a blessing. I am getting it next week. Hallelujah!

Fiber to the house can be a blessing.

Absolutely, but the point of the article is that if the Ethernet goes outside your home to the fiber interface it can be a surge path.  @spenav 


You are probably thinking of fiber-to-the-curb. Now they bring it right into your garage. The only copper involved is your house wiring. Sweet! And since my DAC has a fiber port, I already have optical from my switch to the DAC. Sorry if I am a little outside of the scope of your post. I just had to tell somebody 😀

. Now they bring it right into your garage.


Sweet!  Not sure the terminology, but what if you don't have a garage? :D 

I've seen them bring the fiber to the outside of the house wall, and then run Ethernet within.  Those are the edge cases where Ethernet protection still matters more than you'd think.

Great article erik_squires. Thanks for posting. Having been a Radio Broadcast Engineer for many decades, I've really been dealt my fair share of forced education related to lightning damage, and lightning strikes. It has been an unbelievably (shocking) wild ride. I have typically been employed at radio station clusters that had already been built that were experiencing lightning damage to equipment when I first walked in the door. IMO, maintaining lightning protection integrity in broadcast facilities is almost an art form. One of my co-located facilities' (studios/offices co-located with transmitter site) towers would be struck at least 12 times a year, and many times *more* than that (I had an AM transmitter at that site that would visually notify of a lightning strike, which made it easy to count strikes to the tower per year). Trying to gain control of a broadcast facility (with thousands of wires and interconnections) that is suffering from lightning strikes is not an easy task. I could talk your ear off on this stuff, but I'll make it simple. The plan that worked the best was overhauling the star-ground system at each facility I worked at. The most basic cure-all was making sure everything was at the same ground potential (all grounds were tied together). This also included bonding all water pipes, gas lines, building structure rebar, and outdoor satellite dish ground pedestals to the star ground system. If a good ground system (with at least 8-10 cadwelded together ground rods, tied to the star-ground system) was not already in place, one was installed. Every piece of copper communication cable that entered the building was also treated with some type of surge protection, tied to the star-ground system. Once I did all of that at the facility I'm referring to, everything settled down, and we never experienced another lightning strike equipment fatality at that facility as long as I worked there, but I always kept in mind whenever an electrical storm blew through, that lightning protection is rarely ever a cure-all, but more prevention. I never assumed we would never suffer another piece of equipment being blown up from a lightning strike, but I am proud to say that I really did get it under control at that facility, and others that I maintained. I use much of what I learned at the broadcast facilities when wiring my home audio, small home ethernet network and AC home wiring, even though I don't have a 410' lightning rod in my backyard.