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Dangers of lightning
Friday 11 January 2008 12:07:03 by Andrew Ferguson

How many people disconnect their ADSL modem and computer hardware from the telephone line when there is a lightning storm? Probably not that many.

People living in South Brent (near Totnes in Devon) have seen the effects that a large lightning bolt can have. BT has had to replace 85 metres of overhead cable, and local computer stores are reporting a rush of kit to be repaired, including modems, routers, printers and phones damaged by a large single lightning strike.

To read more on the bolt from the blue visit DartmouthToday.co.uk. There is not much you can do to protect your expensive hardware from a direct strike on your home, but devices like surge protectors (which need to be ADSL compatible) can help to reduce the risk of damage from strikes further away.

Most ADSL modems include a sacrificial component that will destroy itself if a surge occurs over the telephone line to protect kit connected to the device, but in the case of a near or direct strike the amount of energy involved will jump this broken component.

Comments

Posted by CARPETBURN over 9 years ago
Quote"There is not much you can do to protect your expensive hardware from a direct strike on your home"
Apart from do the sensible thing which was touched on and say to yourself my god this is a bad storm then run to unplug your router, plasma tele, 10 million different digital boxes connected to said tele etc.
Dunno about others but if outside my window a huge storm was going on i wouldnt just leave all my top end kit plugged in.
Posted by strzelecki over 9 years ago
All very well saying 'unplug you electrical equipment', but what if you're not at home when the storm develops?
My house was struck by lightning in June '07, fried my ADSL and network equipment and knocked out the electricity supply to over 400 houses.
After a 4 month insurance claim everything connected to my telephone line and most sockets are surge protected (computers were surge protected before but that didn't save them).
Posted by zenops over 9 years ago
I had a server two laptops and three desktops connected at home all surge protected. three devices were on one protector module and two survived one had the motherboard fried.

I now leave my older kit outside when storms occur and after i've checked my Insurance cover is valid and covers replacements ;-)
Posted by CARPETBURN over 9 years ago
quote"All very well saying 'unplug you electrical equipment', but what if you're not at home when the storm develops?"

Considering this storm took place at around 5am i imagine most were at home and most were woken by it. Id even go as far to say that most idiots were too busy watching it rather than unpluging gear they have spent thousands on.

Fair enough with the if "not at home" comment, but in this case its likely most were.
Posted by speedyrite over 9 years ago
Does this advice also apply if the telephone line to the home is not via overhead cable? There are no telegraph poles on my estate at all, the phone cabling all seems to be underground in the local vicinity.
Posted by Dawn_Falcon over 9 years ago
Zenops: Lightning damage is usually excluded.
Posted by irrelevant over 9 years ago
quote the article: "But witnesses report just one single venomous ‘bolt out of the blue’ around 5am."

Hard to anticipate that one - by the time you've been woken up, it's too late.
Posted by CARPETBURN over 9 years ago
quote"quote the article: "But witnesses report just one single venomous ‘bolt out of the blue’ around 5am."
Hard to anticipate that one - by the time you've been woken up, it's too late."
Id imagine there was more than one bit of lightning and plenty of thunder and rain. Infact to see this venomous bit of lightning you must of been awake anyway, unless these "witnesses" saw it in their sleep!!
Posted by CARPETBURN over 9 years ago
Moral is still if at home and theres a storm no matter how minor or major it seems to be.... Unplug your equipment... Its not rocket science.
Posted by zenops over 9 years ago
Dawn_Falcon - Not if you pay for it ;-)
Posted by Dawn_Falcon over 9 years ago
Zenops - Well yes, but it's usually excluded from the basic policies :)
Posted by zenops over 9 years ago
Yeah that's true but always wise to check I find ;-)
Posted by iball over 9 years ago
This seems to make a mockery of the UK EMC laws which basically state that the equipment will operate as intended within it's intended environment.
Posted by g8eqz over 9 years ago
Electro-magnetic compatability is just that; the device will not cause excessive RF fields or malfunction in strong RF fields. Nothing to do with a lightning strike wich is more like the EMP from a nuclear blast!
Posted by loumaulecole over 9 years ago
I presume CARPETBURN never goes away on holiday, or business, and is a light sleeper!
Posted by BrianThompson over 9 years ago
I've lost five TV aerial amplifiers in ten years to lightning surges down the aerial lead; plus two telephone modems and one ADSL router via the 'phone line. I cannot isolate the TV amplifier easily when storms are about - it's in the loft - and both systems are 'protected' with surge suppressors. Belkin claim there is nothing wrong with the suppressors - yet the connected equipment stopped working! What did one correspondent mean exactly by an ADSL enabled suppressor? I've never heard of them.

Wayside
Posted by daringdave over 9 years ago
Recently, I've had to remove a Belkin ADSL surge suppressor because of the havoc it played out on the voice line. Now I see it's not much use against surges (admittedly extreme surges). Are these devices worth the money?
Posted by oldswan over 9 years ago
I suspect that there is not too much you can do if you get a sudden storm. I've had a telephone handset burnt out whilst actually using it, a surge protector burnt out, and an internal computer modem fried. I've also lost several TV aerial amplifiers. BT lost a whole length of cable which supplies about 12 properties locally when a lightning strike fried it and melted all the cores together, the same strike that blew my phone.
Posted by 961a over 9 years ago
Two things...
First, the problem can come via the phone line even if it is all underground. Always disconnect if a storm is forecast
However, it is extremely dangerous to try to disconnect cables etc during a storm. Remember this stuff can fry you as well!
Posted by BBSlowcoach over 9 years ago
Is it true that the surge protection manufacturers - Belkin etc - guarantee to protect equipment, up to certain values, damaged by such events when connected to their equipment? Perhaps claiming against the guarantee rather than house contents insurance policies is a better route for recompense.
Posted by bowtiejim over 9 years ago
One of the problems of living in the sticks not forgetting slow download speeds. We had a strike on an overhead BT cable a few years back which took out three or four computers in the village. We have at least one power outage a month making a UPS a necessity. But a nearby strike more than likely will cause collateral damage. Unplugging the Modem is a chore, but only a fraction of the one following a severe strike.
Posted by muymalestado over 9 years ago
So, is this kind of thing worthwhile?
http://www.clarity.it/cgi-bin/sh000001.pl?REFPAGE=http%3a%2f%2fwww%2eclarity%2eit%2facatalog%2ftelecoms%2ehtml&WD=protector%20surge&SHOP=%20&PN=surge_protectors%2ehtml%23aadsl_2fprot_2fxk43#aadsl_2fprot_2fxk43
Posted by cottonsvyner121 over 9 years ago
Fit copper lightning conductors externally (cheap), breakers on main fuse box(if renting ask landlord to do these) and (obviously) unplug/detach kit from electrical circuits. If away from home and in vehicle stay there - a strike may damage vehicle but it will save you.
Posted by CARPETBURN over 9 years ago
quote"I presume CARPETBURN never goes away on holiday, or business, and is a light sleeper! "

I presume being stupid when you go on holiday you leave everything plugged in. :rollseyes:
Not to mention my post of "Moral is still if at home and theres a storm no matter how minor or major it seems to be.... Unplug your equipment... Its not rocket science." Which obviously was too hard for you to read.
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