Power Surge

[Kjonnnn]

We had a big lightning bolt hit here Thursday. It fried some components.

No computers were damaged, but it blew two hubs.
In other cases, it blew the surge protector.
In a few more cases, it only blew the network cards.

Just curious. How could the power surge skip the surge protectors and the hub and just fry the cards. The computers themselves are fine.

Anybody experience this before?

 

[Krosus]

Just a guess but network cables can carry charge just like any other wiring maybe the surge went thru the blown hubs.

As to how the surge got through the surge protectors to the hubs is another matter. Again purely speculating but a large enough surge would probably overwhelm the protectors and some charge would get through.

Feel free to poke holes in this im no professional Electrician but it seems plausible.

 

[Jonmonster]

Nothing can stop a direct hit from lightning not even the best surge suppressors. As far as why the NICs took a hit? Krosus is right. The lightning hit was just trying to find the quickest route to ground and unfortunately found it though your NIC cabling to the NICs. I'm surprised the computers themselves didn't take more of a hit than they did. I've seen motherboards completely fry like that. One thing to look out for, though; just because it appears that the computers did not take a hit does not mean that they didn't. After a few weeks of use you may notice things like "Blue screens," GPFs and exception errors. This might indicate that the memory, processor(s) or motherboard did in fact take a mild to moderate hit. In cases such as this for me in the past, it became more cost effective to chalk it up as a total loss and completely replace the systems. It isn't worth the troubleshooting effort or the component replacement cost. Also note that with component replacement, that sometimes the new components you just bought fry due to over-voltages caused by other bad components. I guess when it comes down to it, electrons simply have minds of their own.

Also, I don't know if this is your case or not but most people surge protect the heck out of their computers but tend to forget to protect hubs, switches, routers, phone lines, ISDN, cable lines, and DSL ports which can all be points of entry.

Anyway. That was my two cents.
-J

 

[edfair]

The hit wasn't to your cabling. The hit was close enough that you got an induced spike to your cables. Your powerline and telephones are protected (somewhat) but your cat5 has only what is provided on the card itself.

All it takes is about 2 volts more in reverse voltage than is protected for to fry chips on the NIC or in the hubs.

And your computers may be fine now, but if it came to the network cards it hit the innards too and they are probably weakened and their lives shortened.



Ed Fair
Any advice I give is my best judgement based on my interpretation of the facts you supply. Help increase my knowledge by providing some feedback, good or bad, on any advice I have given.

 

[Kjonnnn]

Thanks for you input.

For some reason, only one part of the network was affected. The rest of network didnt "miss a beat" and was fine. You're right though, after use, some other things may fail. In one computer, the card fail two days later instead of when the others failed.

The bolt also blew out part of our HVAC, 3 phone lines, and a couple of modems (internal and external).

 

[edfair]

I know how those things go. I was designing meter boxes a long time ago and we had one that blew the innards about 30 feet off the side of a house on a hit.

I also lost 3 external modems on 1 near miss at the house a couple of years ago.

I hope you have replaced the surge suppressors. The surge absorbing powder crystalizes as it absorbs the hit and is used up. You usually are advised to replace them at intervals in normal use, but a hit like that would probably indicate you should do it immediately. Ed Fair
Any advice I give is my best judgement based on my interpretation of the facts you supply. Help increase my knowledge by providing some feedback, good or bad, on any advice I have given.

 

[Kjonnnn]

Thanks for the advance... didnt know about that.