Lightning strike- Yes they do happen

Early this morning a neighbour's house was struck by lightning. His modem, phones and several other phone connections upstream of his location are toast. As his upstairs electricity wiring was also fried it has not been possible to establish the condition of one of his three computers, the other two are ready for the recycle bin.


When it is as close as that it brings home the point that if you value you data you should keep a copy seperate from your computer. As a long standing backup addict that is what I do. When all the smoke and dust has settled I have a feeling that this neighbour may well become an Acronis customer.

Xpilot

 

In addition to Acronis, ALWAYS unplug the phone wire from the modem when not in use and NEVER use the phone port in the modem to plug in a phone. A good battery backup UPS might have saved him too.

The damaging lightning spikes can travel on the phone wires from 5 miles away and fry a modem and more. It isn't always the ones on the electric wires that do the damage.

 

I can attest to the phone connection problem. I've lost 2 motherboards [and modems] to lightning over 10 yrs., because I had unplugged everything BUT, a Mickey Mouse phone [don't ask] on one occasion, and this last time... the lightning came before the storm warnings. :\

That last time was August of this year, and why I wound up here.

mm

 

here is another recent (yesterday I think) thread out in the general forum with some additional good advice and discussion.

 

As Ralphie suggested, I would NOT have a computer WITHOUT it being hooked up to an APC Battery Backup. I've always had one. My first was the APC500 back in 1999, and now, I have the APC800 which works great. APC guarantees up to $75,000 for any electronic devices (Computer, Monitor, and etc) that are damaged by Lightning!! This alone is enough to convince anyone to get one. Whether or not...you experience Power Outages, Brownouts, Spikes, and Surges....I strongly recommend anyone to get one.
But however, the ONLY true way to avoid any lightning damage ..is to unplug your whole system from the wall. (modems, ethernet cables, monitors, PC, and etc)

XPilot is right about Data. Never put anything on your computer that you don't have backed up to another HD. (docs, files, programs, Mp3's, Pics, and etc.)

 

Folks should be advised that a lighting strike to the house wiring is not going to be blocked by any household surge surppressors -- whether a series or parallel device. A direct hit is simply thousands of times way too much energy -- you'd be lucky if the house wiring didn't melt. But most "lightining strikes" aren't direct hits electromagnetic pulses in the power lines from nearby lightning discharges.


For non-direct "lighting strikes" and other lesser surges, surge protectors are always a good idea. However, understand that most surge surpressors, even the ones in Line Conditioners, Power Backups, and Regulators usually rely for surge protection on MOVs (Metal Oxide Varistors) wired in parallel with the unit to be protected. Above a certain level of energy, the MOV passes current, shorting the surge across the power line to gorund up stream from the unit to be protected.

Unfortunately MOVs are sacrificial safety devices. They can take a limited number of surges and degrade more quickly the stronger the surge. Even more unfortunately, MOVs don't set off warning lights when they are no longing functioning.

So it makes sense to replace surge protectors periodically unless you test the MOVs. How often depends on how often you get sizeable surges. Some folks recommend once per year as a rule of thumb.

Alternatively, you can use series mode type surge protectors that don't rely on MOVs -- these usually employ large inductors wired in series with the load plus crowbar circuits. The series mode type aren't especially ingenious as far as circuits go (nor are the MOV surge supressor circuits for that matter), but the series mode type tend to be many times more expensive than MOV units.

good luck,
sh

 

Shieber, what you said about Surge Suppressors and MOVs is precisely why I find them to be a waste of money. Those MOVs will sit there not being able to function and you will not know it until it is too late. And in any of the states with more than their fair share of lightning and all the accompanying brownouts and blackouts, a UPS is a better place to spend the money.

 

You are so right. A direct lightning strike would laugh at the puny protection provided by the various devices one can purchase. Indirect hits can be mitigated and as they are more frequent it may be worthwhile to install some protection.

The incident that led me to start this thread was a direct hit on the house concerned.There was no forecast warning of thunder storms. None of the computers were switched on at the time though all were plugged in to the mains supply. They were all connected to the ADSL phone line via a router. The router is now a melted mess and the upstairs mains wiring has been blown away.

The computer damage was on two fronts. Via the Router connection and also via the electricity supply . All three computers are now history. It remains to be seen if any of the hard drives have survived and if so whether their data can be saved.

At a nearby house which is on the same telephone cable bundle their modem was fried as was the switched off but connected laptop. Even worse a flash pen drive which had been left plugged in and which contained vital info was also destroyed. 500Yds further upstream another resident has had to replace his router though the rest of his equipment seems to have survived.

The moral of this episode is to backup your unreplacable data and keep it separate from your computer. Take precautions to protect your equipment but of course this can always be replaced.

Xpilot

 

Just curious ... what city was this?

 

Not a city. Rural Kent England.
Unfortunately in this area the phone lines are strung between poles above ground. In certain places the same applies to mains power feeds.

Xpiolt

 

A UPS won't protect against surges unless it has surge suppression built into it, as many do, albeit via MOVs.

The non-MOV suppressors rely essentially on two features, a large inductor to impede high frequency surges and clamping circuits with very large capacitors to absorb low frequency surges and (relatively) slowly bleed the energy off directly to the neutral powerline.

Some brands are rated to remain functional after 1,000 strikes of several 6 thousand volts of over a 1,000 amps of momemtary surges. These kinds of unis usually cost a few hundred dollars as stand alone suppressors. It's no problem at all to build these kinds of circuits into UPSs -- however, the marginal increse in the cost of the UPS is proportional. If you rely on a UPS for surge suppression, check out what suppression methods the UPS unit employs.


MOVs are so cheap and series mode suppressor so expensive, it can make more sense to buy the cheaper MOV type suppressors and just replace them, say, once a year.

If what you are protecting is "priceless", a series mode suppressor is certainly worthy of strong consideration.

A direct lightning strike, of course will melt the innards and wiring of most of what is connected to whatever took the actual hit. A direct strike to a power line can melt the innards of the stepdown transformer on the powerline pole. But luckily direct strikes are very rare. More common are surges in the wiring do to a nearby discharge.

 

Although I don't own any of these devices other than some power-bars with MOVs and MOVs I've put into power bars myself other sources indicate the best protection is the so-called "whole-house" protection.

This is a device installed like a breaker in your main panel. The deficiency of any of the other devices connected near your computer is the impedance of the ground wire running back to the panel. The whole-house device is tied to ground by the heavy, short, low-impedance ground cable and thus is much more effective in shunting surges to ground.

My wife is always monitoring the weather and if there is a thunderstorm approaching we unplug the various computers including the telephone line to the modem. So far we have blown 2 Sears garage-door opener boards (and now it gets unplugged) although the Stanley opener has no problems.

If you are concerned about the safety of your data then keep a backup off-line. Nothing will protect you if you get a direct or a very close to direct hit. I have seen lightning damage done to larger computers protected by expensive UPS systems.