lightening strike

[adamandamy]

We had a customer experience a close lightening strike the other day and the only 2 pieces of equipment that were effected (made inoperable) were his ethernet switches. He has a Netgear FS116P and a Adtran 6355 switch/router linked together over a 50foot CAT5 cable. He didn't lose any SIP phones or computers and the street power never blinked. Both swiches are on UPS/ Surge protection anyway.

My assumption is that the power spike came through the CAT5 that links them but the cable is still usable with no degradation of link speeds.
Any other theories?

 

[edfair]

Sure, it came through the cat5 cable. You have a huge current flow across a wire and you have a generator. A negative spike flows backwards through a junction and it fries.

My favorite is Stone Mountain Park in Georgia. They used RS232 to control fireworks. After every storm they used to go around replacing line drivers and receivers, which they bought in 1K lots.

Even though it looks like nothing else has failed you need to be aware that every near miss like that affects things and make it more likely to fail in the future. Whatever got to the NIC also got into the other parts.

Ed Fair
Give the wrong symptoms, get the wrong solutions.

 

[technome]

Electromagnetic pulses produce by lightning hits can destroy electronic devices miles away. I was a Consultant for an Oil bunkering company which was losing Sierra wireless modems, used for ship to shore data communications, at an alarming rate; 1 per week in the winter months, 2 per lightning storm at >$500 a pop.
The two causes were static electricity produced during the winter month, as dry air moved passed fiberglass masts antennas. The other, was lightning, but a direct hit was not needed. I had a multimeter connected to an antenna for testing as a thunderstorm was heading towards the ship yard. The storm was >4 miles away, but a large hit on a building at that distance created enough pulse to kill the modem. We ended up getting protection devices from Hyperlink, after which no modems were lost.
If a surge did not come the cat wiring, then it could have been a pulse on the wiring or via any device which is not shielded such as plastic cases used on many devices on a network.
As to built in power anomaly circuits in BBUs and plug in surge protects, they are not the best quality as the manufacturers could not afford to implement them if they were. I picked up a few commercial suppressors equal to the item below, on Ebay which original cost >$2000, for less then $100/piece delivered.

http://cgi.ebay.com/Northern-Techno...ms=65:3|66:2|39:1|240:1318|301:0|293:1|294:50

Cat5 protection, Hyperlink

http://www.l-com.com/productcenter.aspx?id=2064

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Chernobyl disaster..a must see pictorial

http://www.kiddofspeed.com/default.htm