Clive Wilkins, Sutton Coldfield asked:
My Dad always used to unplug the TV when lightning was nearby, was this the right thing to do? And, if you'll excuse the pun, Watt is the Current advice?
John Hammond, Met Office:
Even if nothing happens to the television aerial the wet walls will be quite good electrical conductors. Youíll get quite large current coming down the walls on the outside of the building. Those changing currents will cause magnetic fields, which in turn will induce EMFs or voltages in what could be any electrical equipment in the house. Iím afraid the answer is thereís probably not much you can do about it apart from lying back and watching the show.
My mum always unplugs the aerial from her TV during a thunderstorm. She heard, aparently, of someone who was less cautious and suffered a "telly-detonation" when lightning took a trip down the aerial lead from the roof one day. I've no idea if this is true or not though.
I would say it is better to be safe than sorry!
That is definitely true. When I was at school in the early days of computer networks (we had a school-wide Econet network of BBCs!) a bolt of lightning hit a tree near a classroom. The computer was fried and all of the other computers close to it on the network were also internally dismantled, so to speak.
I was told when I had my first ever PC and that was in the last decade that each time there was a thunderstorm so that I should unplug the computer or just turn it off, in case I got an electic shock.
It is better to unplug a TV aerial (if roof mounted) in a thunderstorm as the aerial could receive a substantial charge from a nearby lightning strike. Being plugged in will also lower the impedance to ground and could make the aerial a slightly preferential path for a discharge. Having said this, it is fairly unlikely to be a problem unless your house is prominently on top of a hill as well. How often does your house get struck by lightning anyway? It matters much less if your aerial is in the loft. Telephones are less of an issue, despite the miles of overhead telegraph wires, because there are devices to limit the voltage excursion and any damage from anything but the most severe and closeby strikes. If there is an actual nearby lightning strike, unplugging equipment could save the equipment, but for most people this is a very unlikely event and, unless you consider yourself to be particularly unlucky, probably not something to worry about too much.
We had a lot lightning damage a few years ago. It came from the phone line. It blew up quite a lot of stuff, two PCs (with internal modems), two SKY boxes and a scart port on one TV. A few other people in the area had modems and phones damaged.
You can put a surge protector in the phone line (not sure if you can get surge protectors for TV antennae cables, but I could imagine they are available). another_someone, Thu, 17th Apr 2008
In the UK the telephone master socket should have surge protection anyway.
Apart from the obvious potential for catastrophic damage if you get a direct hit, you might also get a slow discharge down a TV aerial lead if connected to a TV as the charged clouds pass over.
We are right next to a church. It had a big hit a good few years ago, it blew the fuse box off the wall. I think it was gods way of saying 'get a lighting conductor'.
I seem to remember the best place to be is a distance away from a tall object of half its height. I don't remember the reasoning but it maybe a minimum field position assuming the ground and the object were all conductors. It is also wise to stand with your feet close together to avoid the voltage difference between them if the ground is not a perfect conductor. If you are right next to a church and your house has had damage from lightning, I would assume this is not a wholly unlucky, random event and would take some precautions. graham.d, Sun, 20th Apr 2008
Yes and you will save yourself a lot of cash . Turn off your computer also Alan McDougall, Wed, 25th Jun 2008
I think it best to turn off & disconnect the aerial or it could act as a conductor. In fact I think it often best to turn off the TV even if there is no storm. Saves you being subjected to a whole load of %$*"x@ such as Constipation Street. Don_1, Thu, 28th Aug 2008
Yep we have lost computers here in lots of times whole offices have their computer systems wiped out in thunderstorms and it is always best to unplug the TV etc.. during thunder and lightening storms.. I unplug my TV, RADIOS, AND REFRIGERATOR.. I have been known to stay on line until my power surges to much then I unplug and move to my phone! LOL..Computers are too expensive for me to be replacing! Karen W., Fri, 29th Aug 2008
Karen now that I've got cable broadband/TV that I'd better turn off the computer and the radio/TV but mainly it's just rainstorms. rosalind dna, Fri, 29th Aug 2008
I just do it during thunder and lighting as my homeowners does not cover damage from acts of god or Mother nature! So I unplug, surge protector or no... I would hate for the computer to blow in front of me whilst working on it! Karen W., Sat, 30th Aug 2008
I worked as a TV service tech for 30 years and found many instances of minor damage due to lightning but never any thing major,
25 000 ++++++ posts Karen I am really impressed, I have belonged to a number of forums and no one has come anywhere close to that number of inputs
Not very impressive.. I just like the forum! Karen W., Sat, 27th Sep 2008
observe lighting is one of the most wonderfull things in the world. erickejah, Mon, 20th Oct 2008
well, i too have experienced this situation and my old tv. set was damaged due to it. many mechanics tried to mend it but it didnt work as well as it used to. so i guess it is better we take care of it.
My view i that lightning striking the earth has managed to travel several thousand feet from the clouds, pulling the plug out will add a couple of feet to the route at most.... I won't tempt fate by typing what I then thought! BH, Tue, 28th Oct 2008
It REally Depends On How bad the thunderstorm is.
After two times with "fried everything", I definitely vote yes.
turnipsock "However our premium went up when it should have down since lightning never strikes twice and this wouldn't happen again."
I think a lot depends on whether your mains power comes via overhead lines as is common in America or by underground cable, if the later you have little to fear from power line surges so carry on viewing but overhead power lines can be a menace.
Europe here by the way, cables underground.... highwaykind, Sun, 1st Feb 2009
so if in America turn your TV off because the cables are above ground, but if in Europe you (most of the time) wont have to because of the cables being underground.
Yes. Jdubs, Wed, 6th May 2009