Home Networking

I love the (close-but-no-cigar) citation of the IEEE document titled "Grounding of Industrial and Commercial Power Systems", which primarily deals with lightning protection for industrial and commercial buildings, equipment, power substations, and the like.

It's a good read, if you like air gaps, Faraday cages, and even makes mention of using lasers and rockets to dissipate storm clouds.

Every household should have their own rocket launcher. :-)

No mention of communication cabling whatsoever.

In fairness, section 2.7 does deal with interior wiring systems, but it defers to the NEC with regards to adequate grounding solutions, and, in the first few paragraphs of section 2.7.1, it clearly states:

"Basically, the NEC designates minimum acceptable limits for safety that may not be adequate for a particular application and may not necessarily provide for the efficient or practical use of high technology utilization equipment"

So, the IEEE defers to the NEC standards with regards to proper grounding/protection of interior wiring, and states that the NEC guidelines "might not be adequate for protection of high-technology equipment."

So, there's that.

Yeah, OP could put some ethernet arrestors on both ends of the cable, and then of course bond each one to a grounding source where the cables enter into each building. There are plenty advertised online, many of which come with their own sets of negative reviews after the devices failed to do their jobs, with a few of the reviewers being adamant that they followed the proper grounding procedures.

That of course doesn't mean that some other factors weren't in play, but it is certainly enough to raise suspicion, while simultaneously raising enough doubt to conclude that the devices might not offer reliable/predictable protection, even when installed correctly.

The IEEE 99.5% rule doesn't come into play here, as it only covers unrelated grounding scenarios, and doesn't apply to the real-life performance of the lightning arrestors themselves.

While some arrestors may have failed at their jobs due to incorrect grounding methods, the folks that claimed to have closely followed the included grounding instructions may very well have had a defective unit. Perhaps bad solder joints, a GDT that was compromised due to rough handling during shipping or from too much heat during soldering, or some other internal flaw.

Sadly, there's not a convenient way for home users to test them, other than the "wait and see" method. Not the best way to find out. :-/

As with any gas-in-a-tube device, leakage can develop from sudden impacts to the chassis, or simply from the passage of time, etc. Once the gas is gone, so is the protection for that conductor, and you only need one to fail for catastrophic results.

I wouldn't expect to see a manufacturer's analysis of failure modes and failure rates anytime soon. . . Heheh.

However, you did bring up an interesting point that gave me pause.

"Boxes powered by an electrical source means protection is gone - compromised."

So you're positing that lightning could induce a current flow in the underground cable, which will enter into the first media converter via ethernet, through its electronics, and then out to the building's electrical system via the converter's AC-adapter, where it will then enter the AC adapter of the second media converter, proceed through its electronics, and out to whatever ethernet device it is connected to.

I can actually envision that path, but can't even guess at the likelihood of that happening, any more than I could speculate on the failure rate of ethernet lightning arrestors, or the longevity of the gas-filled tubes inside them.

Either event seems possible, and is a matter of percentages.

Thanks for giving me things to ponder. . .