Lightning strike

[casey 0]

Last week we had a storm come through and a building of mine ended up getting hit by lightning or close to. The second that the lightning hit I lost the video on the two cameras that I have in that building.

I figured it may have just tripped a circuit breaker or blown a fuse on my power supply. But when I checked my power supply everything seemed to be working. I even checked the power at the camera. My meter said that I had power.

Can a lightning strike have damaged my cameras? Has anyone ever heard of this happening before?

Here is a list of the equipment I am using.

 

Geovision, GV1480

NUVICO, NVCC-HW3895IR36N camera

Surveilux, SVB-54IR28L49 camera

B-Tron DCR4-4-1 12 VDC, 4 output , 4 Amps fused Power Supply.

 

Thanks for any information.

 

Casey

[CollinR 0]

Consider yourself very lucky it didn't get your server, lighting is very unpredictable. I have a system that lost a mouse and a monitor last week, how does that happen?

[casey 0]

Thanks for the info.

If I were to put a 1 amp in-line fuse on the power wire would that help in the future?

 

Casey

[C7 in CA 0]

Can a lightning strike have damaged my cameras? Has anyone ever heard of this happening before?

 

Yes, and Yes!

 

There are a lot of interesting threads on this site about lightning. Personally, I use ample bonding and surge suppression (it's required by the local AHJ). I see lots of guys that subscribe to the "isolation" theory too. But I have swapped out plenty of equipment that has failed from both practices.

[C7 in CA 0]

Thanks for the info.

If I were to put a 1 amp in-line fuse on the power wire would that help in the future?

 

Casey

 

Wouldn't hurt (unless you are drawing more then an amp ) But I doubt it would help much unless it is minor transient voltages that hit ya. Also you would have to fuse both wires, not just the hot side.

[rory 0]

all you can do is have a good warranty and replacement cameras on hand .. when lightning strikes all bets are off! Surge protection doesn't even protect us down here against simple things like brownouts.

[C7 in CA 0]

You know, I think a better solution to inline fuses would be a Transient voltage suppressor. We use them all the time in Telecom building entrance equipment. They have either oil filled, or electronic based. But ours clamp at about 125volts.

 

I would guess they make them to clamp at most voltages though. I thought of them because they protect both tip and ring with one suppressor. All the ones I have seen use ground for a reference point. So if you aren't grounding these may not work for you.

 

And as rory said, brownouts get him. Could have been a brownout after the strike that got you too. Is your power supply on an APC?

[woodyads 0]

I work in a very lightning fertile environment. Lost 70% of my main comms room once and it took me 3 months to get it all going again only to have it taken out again this time about 80%. We lost

 

80% of a PABX ie 80% of the cards had blown lines.

Main Router,

Mobile Phone Power supply fried

2 x 2way repeaters.

1 Minilink (Ericcson Microwave)

Main Microwave

Voice Mail Server

2 x ISDN boxes

Several Data modems

Fried a 150 pair Phone cable

The list goes on

 

My diagnosis was the hit came from the earth. I had a data modem that had its feet melted and a great big burn mark on the bottom, So I threw it in the definitely stuffed pile. When I finished fixing everything I tested this modem and it was still working. The strike had come up through the earth and jumped to the chassis of the group switch it was sitting on. The power supply and the main board were unaffected. When I started on this job 8 years ago. I had about 5 devices which would self destruct every thunder storm. I would loose the Minilink (Ericcson microwave connecting our village to the site) about 5 time a year. So I eventually replaced all copper between buildings with fibre and got rid of the Minilink and replaced it with a more robust device.

 

Took me ages to diagnose why the Voice mail server stopped working. It ended out that the Parallel port got fried. So the whole thing was working apart from the licensing dongle. But there was no obvious sign this was the problem. The machine had 4 ISA cards in it and I could no longer buy another main board with 4 ISA slots. So I couldn't just migrate the box to another machine to diagnose the problem.

 

Most of the PABX took hits to the filter cards that are designed to be a low cost sacrificial card. Still a pain when 70% of them go. A few of the main cards got fried as well.

 

Microcell lost its main board on the power supply. This was a big 32ru rack power supply.

 

Cisco Router, I lost this about 4 times in 4 years. Just totally fried every time.

 

So what's the lesson. Several device I would loose all the time but all these other devices would normally survive. But when you get a direct hit nothing is sacred. You can't stop lightning, a fuse won't be enough as the weakest component in your device may go before the fuse and lightning can come from any direction, up from the ground, building to building. The best you can do is put in fibre everywhere but if you get a direct hit only luck will save you.

 

But when you do loose gear it can quite often be fixed especially if there is no big black marks on them. It doesn't take a lot of voltage differential to destroy some devices at their weak points.

 

Here is another rule. When you have to running copper between infrastructure you only earth the shield at one end. Don't earth it at both ends. The Voltage differential between two buildings can be enough to destroy electronic equipment even with out a lightning strike.

 

True story, Group of soccer players standing in a circle around their coach at training during a thunder storm. Lightning hit the ground near by and the guys with one foot closer to the lightning than the other got killed and the ones with their feet equal distance to the strike survived. Same with buildings the building closer to where the lightning hits the ground has a higher potential than the building further away. So if two buildings are joined by a copper cable then the voltage will flow done that cable to equalise. I recon most of the carnage we experienced was from ground strikes. The big one's where from direct hits to the main tower but I believe it was venting to earth to other buildings was killing most things.

[wisp_engineer 0]

Sorry to hear about the losses.

 

 

Being in the communications business primarily we spend countless dollars on our own infrastructure to attempt to protect it the best we can. There have been times that there were direct strikes, and nothing was damaged and then there are times where there are direct strikes and the breaker panel is thrown off the wall, equipment is blown to pieces, etc. Lightning is a quirky animal and you can only do your best to make sure EVERYTHING is bonded and then grounded so that it is all at the same potential. In theory, electronic devices could get struck by lightning and make it out unscathed, but only if EVERY component is at a common potential to earth and capable of dealing with the voltages induced during the strike.