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View Full Version : ADSL routers vulnerable during electrical storms?


Gonzo
27th Jan 2005, 15:02
A few years ago my dial up modem was frazzled by an electrical storm, as I had not carried out my usual step of unplugging. With ADSL routers supposedly 'always on', do they carry any protection or is one still advised to unplug?

Coconutty
27th Jan 2005, 17:40
If there's an electrical storm I generally switch my PC off and unplug it - even with Surge Protection and UPS you can't be too careful - no good crying after your computer's been blown to bits - even if you manage to get your insurance company to cough up they won't replace any lost files :hmm: ... but I usually leave the modem and router on to save any hassle on powering back up - reconguring IP addresses etc that sometmes go astray if you pull the plug(s).

My set up has a seperate Broadband modem supplied by NTL ( who will replace it under my monthly contract with them if it goes bang ), and my Router is then plugged into the modem.

The NTL engineer tells me that there's a little square metal connection box in the wall plate which provides protection against lightning strikes, power surges etc. at the same time as controlling the signal level coming down the line to the modem. Hopefully this would also provide protection further down the line past the modem to my router - the law of the sod says I'll probably find out soon so I'm off to check the Met !

Hope this helps.

Evo
27th Jan 2005, 17:54
I know someone who lost an ADSL modem during an electrical storm, so it can happen :{

I have a UPS (APC CS350) that has a surge protector for the phone line, so my connection is routed through that. No idea if it works, don't want to find out either :)

Gonzo
27th Jan 2005, 19:44
I was always under the impression that anything connected to a phone line was much more likely to suffer than electrical connections from lightning strikes.

I've never unplugged power leads; the modem that was frazzled was an internal PCI card. It was completely useless, but the PC worked fine, so that implies it came through the phone cable and not the power lead. I guess.

Irish Steve
27th Jan 2005, 23:49
Good few years back, house near us took a direct lightning strike, which blew most of their sockets off the wall, and put the chimney throught the roof into the room below.

Here, about 100 yards away, the Fax/Phone intelligent splitter box fried, as did the modem in the PC, though the fax escaped.

Every TV in the house was damaged to a greater or lesser extent, and we also ended up having to install a new switchboard. One TV was beyond economic repair, which was a pain, as it was a nice set in those days.

It was clear that the most serious spikes and damage came in on the phone and Cable TV lines rather than on the main electricity supply.

All the cables locally were underground, so it wasn't a case of induced spikes in overhead wiring, I suspect that the problem was more related to the lack of local earthing on the "other" services, at least with the main power system, there are connections to ground all over the thing, so any spike can be discharged more readily.

Even with a UPS, there are risks to equipment from surges, it depends on how the UPS works, and it's quality, in that if it "supports" the mains, rather than converting incoming mains to DC, and then producing "new" AC from the DC or battery as appropriate, there is a risk that a high surge can get past the internals of the UPS, with the potential (arrghh:O) to do damage to whatever is downstream.

So, to disconnect or not. I suppose the safest path is yes, if there's significant weather about, then disconnect, but do make sure that you know what the settings are for any box that's going to be powered off. Also, remove both the mains lead AND the incoming line. A spike on either can do damage even if the box itself is powered down.

Some of the more expensive and complex protector devices for power and lines can help, as they have the internal components to provide the protection to the equipment that's connected. Be warned, in some cases, if they do provide protection against a strike, it may be necessary to have some of the internal components replaced, as they are designed to fry and protect the connected equipment, and once fried, they ain't going to work any more.

OK, that's enough for this session, hope it helps

Cheers