Another en-lightning experience…

For the third time in two years, we suffered significant damage from a nearby lightning strike.

Remember the old adage “lightning never strikes in the same place twice” is in fact correct: lightning strikes in the same place many, many times. If you’ve had damage once, expect damage again and again.

We live near the top of a hill, the highest for several miles; and it is covered by tall oak trees. A way to think of our house is as though we are surrounded by antennae. As the amount of electronic gear in our house has continued to climb, repairs have become increasingly bothersome and expensive, despite increasing measures to try to prevent loss.

After the first serious event two years ago, I started to do the usual things of simple surge protectors and UPS’s for the computers. The event of summer 2009 and thousands of dollars more damage made it more urgent, and I started reading about what to do more seriously: e.g. putting in more explicit surge protection on my Ethernet cables, etc.

A good general online reference on how to protect yourself about lightning is “How to Protect Your House and Its Contents from Lighting“,  by the IEEE. After some research (e.g. section 1.1.1.3 of the IEEE document), I realised that the cable entering our house had been installed incorrectly; it entered on the front of the house, and should have been located on the side to enter near the electric service. This is bad… Also note that the phone or cable company put in grounds and various protection for their equipment: but those grounds and protectors are to protect their equipment, not yours.

But I was busy with a new job, and very ill most of the winter and spring, so it was only in early May that I started to really take action. Not soon enough, it turned out…. So I called up Comcast, who had bought the mom-and-pop cable outfit for my town some years back, and asked them to move the cable. I’ll spare you all the gory details of several no-shows followed by other problems; but the net result is that the cable had not been moved by the latest lightning strike that occurred the first week of June.

This time, the strike took out the cable modem (third in two years), several ethernet switches, the pool pump, the washing machine, my router and an access point, the irrigation system, a UPS and a surge protector and maybe the ice maker in the freezer (it has a big bucket of ice, and we didn’t notice for a week that it wasn’t making ice, so it’s probably also a casualty). Our computers themselves seem to have been protected by the UPS/surge protectors. (In past events I’ve lost several ethernet interfaces.)

Sigh…

Now the fire drill started, by urgency of different things to get fixed.

Off to the computer store for a new cable modem (it was Friday night, so I couldn’t get Comcast to swap my cable modem), and ethernet switches. In our house, people get really grumpy if they don’t have their Internet fix. Having had way too much experience debugging my network, I knew exactly what was likely busted and what to buy this time….

BTW, if you have Comcast, and they’ve upgraded your service area to DOCSIS 3, it’s worth getting a DOCSIS 3 modem even if you don’t buy faster service. Their “Turboboost” feature lets you get lots of bandwidth for a short period, and its noticeably faster. But this leads to another set of blogging I plan to do soon on discovering what’s been going on in my Internet service, which I’ll save for a later date, for reasons you’ll understand when you read it.

Next on the urgency scale was the washer… At least the lightning had the kindness to kill our hated washing machine and clothes shredder this time, though of course, it is infuriating that you can’t economically fix things anymore. Figuring out it didn’t pay to get it repaired took days of time, of course, by the time we decoded the washer’s error message, and the repair person said it could be either of two expensive components (the microcontroller and the motor controller), which didn’t want to talk to each other any more.

I also had the electricians in to look over to see if any of my wiring was bad: they did find a loose neutral in the pool shed, which may have accounted for the pool pump, and did other checking. I then arranged for them to put in whole house surge protectors, on my electrical panels. Note that unless you do some homework, you might not realize that such surge protectors have a limited life, so you really want idiot lights on them to tell you, the idiot, when they need replacement.

I also had to figure out what to do about the pool pump, which had its electronic brain fried and the pool was turning green. I had been very happy with the new one I bought a year or two back; the Pentair Intelliflow is amazingly low power consumption and extremely quiet, immensely better than older pool pumps. By running the water very slowly, you reduce the turbulent flow in the pipes and it is much more efficient than conventional pumps. I had figured it would pay for itself within a couple years. But the pump gets this by electronic smarts, and they fried. Again, the pricing is such that it doesn’t pay to replace just the pump controller; for only a hundred or two dollars, I could buy an entire new one from Amazon. Grrrrr…. Another example of “you can’t repair things anymore”…

Next on the list is the yard; it was wilting in a dry June summer. This time, the controller was “blown up”; you could see blackness around the electronics controller, and its door blown open, and its surge protector fried. Something slightly less dramatic occurred a year ago, and you can’t really get old fashioned mechanical controllers any more (that had run the irrigation system for so many years). I call up the contractor who had installed it, and ask them to come fix. He installed a new controller, but was completely incapable of figuring out why 1/4 of the zones wouldn’t work. The guy they sent had no idea how to use a multimeter to debug the problem. I got to teach him how to use a meter, to figure out the common on that cable was open causing all zones on that cable to not work. (that cable went near the tree that came down in the storm when the lighting struck; the two may be related). And then I taught him to do a binary search to determine which segment of cable was damaged… Of course, this defeats why you call repair people in the first place; one might hope you don’t have to teach them how to do their job. He should have been paying me for the lesson in repair; rather than me, paying his employer… After much hassle and a day of wandering around the yard, water was flowing again (though I still have a few zones to fix).

It is clear ham operators know lots about lightning, and they are a garrulous sort by nature and like talking about technology. I gave my friend Bdale Garbee (KB0G) a call. While living on a dry mountain side in Colorado (where it is hard to get a good ground and lightning is frequent), and his wife Karen observing 2 direct strikes on his antenna, he’d had about $100 total damage in 25 years. That was more like it. The ARRL has some very useful lighting information on their web site.

My reading last fall and this spring helped me decide to to emulate what the radio industry and ham’s do, and install what is called a “single point ground system” in my house. Any wire entering the house may be the source of your surge; you have to protect them all. In short, you bring every ground to a common ground plate; the house electric ground; the surge protectors for the cable, the surge protector on the telephone line. The idea is you want to keep everything at the same potential; it is voltage differences that cause destruction of equipment. You really want to tie together all the grounds at a single point, else a surge from one wire entering the house travels across the house doing its thing until it reaches ground. This is why having my Comcast cable come in the front of the house was such a problem; a surge from that direction might first enter the house, and then find things like my computer network or the house wiring the easiest path to ground. A year ago, the wall wart for my cable modem was blown across the basement…

I’d already not been happy about my electrical ground: it is a big cable that runs all the way back across the house to be bonded to the well casing; it’s a long run, and I’ve observed electrical noise problems in the house (which I now take to be a sign of a bad ground, having educated myself). If you ever build a house, learn about what is called an “Ufer” ground.

So I decided to take two further steps beyond simple repair, moving the cable, and surge protectors in my panels:

  1. install a single point ground system.
  2. improve the ground for my house.

I’ll talk about both of these steps in future installments on this blog, now that I’ve installed both of these. I had loads of fun with exothermic welding today.

There is a moral here: as we get more electronics in our houses, more and more people will have experiences like mine. If you ever have damage from surges, take the first event, however small, seriously…. It probably won’t be your last.

5 Responses to “Another en-lightning experience…”

  1. Another en-lightning experience | 9nd.pl Says:

    […] gettys […]

  2. Another en-lightning experience… « jg's Ramblings >> Surge Protector Suppressor Says:

    […] Cable surge protector – Google Blog Search by jeremiah.andrick […]

  3. freesoft Says:

    Thank you..really informative!!

  4. M Says:

    In the UK, within a very short distance from the “electrical panel” there must be be a main earthing terminal, and services entering the house must be bonded to the MET within ~0.5 m of their entry…

  5. Home Router Puzzle Piece Two – Fun with wireless « jg's Ramblings Says:

    […] more definitively. I suspect more recent home routers may behave worse than old home routers; but as my old routers have been blown up by lightning, I can’t test this […]

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