[sangram]

Hi

There's this setup me and a friend have installed, a LAN with about 100 computers spread over a few square kilometers. We've taken a lot of help to do it, and the setup was running well till last week.

There were a few thunderstorms last week, which took out about 30 computers, two switches, and 40 LAN cards with it. Since the only way such widespread damage could have occured is if lightning hit one of the switches, we're rewiring the whole thing in two weeks. Meantime, what would be a good way to remain portected from future lightning strikes, if any such protection is possible?

[arhines]

If you keep all of the network connected devices (computers, hubs, etc...) behind surge protectors, you should be just fine (i'm assuming it came in via a switch which had an xformer plugged straight into the wall at some point).

[sangram]

OK actually in this case the LAN cards and mobos had been visibly burned, which leads me to believe the spike travelled down the LAN connection. I hope a spike suppressor would help me there? I thought not, but I could be wrong.

All the comps are connected to UPS systems, though, for whatever that's worth.

[HaywirE]

Ouch Dude..


What kinda connection you got on that network?

[kooshball]

hooooly **** that must suck.
sorry dude

koosh

[Steelforge]

You can get surge protectors with coaxial and CAT5 protection for $20 to $50 USD. Put them between the exterior line and your switch.

You do this under contract? If that company finds out that a $30 plug strip could have save them $2000+ in burned equipment and they are going to be on your doorstep with court papers. Better kiss-up quick and keep them from talking to another company for consultation for the burn-out.

UPSs have surge protection built into them. You got slapped by your own LAN. That sucks. Big time.

[sangram]

HaywirE: Those are a switch-based 10/100 LAN setup. Unfortunately I have no clue about networking, I'm the guy who built the machines. Sorta screwed now.

Steelforge: Yeah I knew you got surge protectors with LAN surge suppressors built in, the company didn't buy them to save on cost (!) and went for regular wall wiring coming off the UPSs. My partner, who actually did the consulting, got screwed over on this because he set up the network and did the installs.

He's getting jacked now but he's actually safe, at least for now. And the burnt boards, believe it or not, alleviate some of the responsibility, and put it at the doorstep of the big Guy in the Sky. So we have to replace all those machines in the next few days. I'm not sleeping much, so....

We're now getting them to buy the expensive surge protectors. They're buying, which is just as well.

Sang

[Steelforge]

Good to hear.

Did you say you were in Texas? Storm Central and the South side of Tornado alley? I'm on the North side. I keep everything double surge protected. Still surprises me that companies won't pony up a couple hundred once to protect multiple thousand dollars of equip.

Good luck with the repairs.

[Despotes]

That's expensive Surge protectors are good for your general spike, but if lightning hits very nearby, not much is going to prevent that lightning from creating some real damage.
That's part of the reason why I never leave my system running 24/7 and always unplug when I hear thunder.

[sangram]

SteelForge: I'm on the other side of the world, in India.

Economics by companies here run by different rules. They're all what you would call 'Penny wise, Pound foolish'.

Despotes: Exactly what I wanted to know. I was thinking of lightning conductors, actually, as a more or less permanent solution. They have them installed, but I'm not sure because we do have a 2 ohm grounding resistance on the earth lines, which is approaching toast territory anyway, I hate them anywhere above .5/.8 ohm.

I wasn't at all confident that spike suppressors would do the job. We're now going to put them in anyway, and I've ordered a few hundred varistors (I think that's what they are called) and am going to solder them on to the LAN cards to prevent high voltages going through the LAN.

Unfortunately, being an enterprise, I can't really advise them not to run 24 x 7 or switch it off when the storms come by. I am looking at new grounding methods, lightning conductors, installing the switches on the UPS lines, and the above varistors as a combined way of battling the lightning strike. We'll be voiding the warranty on the LAN cards, but what the heck.

[Monaco]

OK- you are wasting your time trying to beat lightning with a surge protector- they are worthless for that. You average good surge protector will eat at most 3,000 joules.

A small lightning strike can easily deliver one million joules!

Even network-sized surge prots. are not enough. A very good constant-charge UPS system, one that always runs the whole network off a battery, would do the trick for powerline strikes. Put the battery between the lightning and the PCs, and they are safe. The extreme charge may fry your batteries, but hey that is why there are gas-powered generators in most good computer rooms

For phone line strikes- tell the phone company to put a can on the powerline pole nearest you or something, or switch to underground wiring! lol that is pretty much it. Actually, calling the phone company for advice might not be a bad idea.

The idea is not so much to harden your system against lightning- it's to design it so a lightning strike will take out one inexpensive, replaceable component instead of the whole server room!

[sangram]

All right, now we're talking. Online UPS systems seem to be a good solution, at least for the mains part of it. For the phone line, the phone institution assures that lightning protection is built in. I tend to agree, since the ISDN line and the computers in its immediate vicinity seem unaffected.

I still have to figure out how to get a spike off the LAN. I assume that if everything is connected to online UPS systems, including switches etc, we should be home and dry??

I still consult with electrical experts, in order to ensure good lightning conductance on the buildings and route the conduction so that it is away from LAN connections and the UPS power systems.

[ShiFtY2001]

Where I live, some guy got hit by lightning the other day: it hit him in the shoulder and went out through his eyeball!!!! unbelieveable, but he lived to tell the tale. Hope he bought a lottery ticket!

[Monaco]

I assume that if everything is connected to online UPS systems, including switches etc, we should be home and dry??

I sure think so. A battery will deliver a constant amperage/voltage, no matter what is going on outside. The battery charger may get abused with spike and surges and such, but the batteries themselves should be largely unaffected. The battery effect serves to smooth away power transients.

BTW did you try pulling components from those 30 affected machines? In my experience a lightning strike almost never fries the whole machine- usually 1/3 or so of the parts in a lightning-struck PC are perfectly fine.

[sangram]

Actually, yeah, we are pulling the components. The strike fried the mobos of about 20 computers, it took out about 40 LAN cards and about 6 switches. Strangely enough, the servers were still working, and those on a few switches. All CPUS seem fine but have returned them for testing to the RMA deptt.. Hard disks are still being tested, but too early to comment.

Sang

[sangram]

Originally posted by ShiFtY2001
but he lived to tell the tale.

Can he still see??