Bad Weather

[TaylorFox]

Alright guys, so we've had some unexpected thunderstorms for tonight, and this is the first time I've had to worry about lightning strike issues. I've encountered heavy rain before, and that's usually never been an issue, even for my outdoor control boxes. But, I have to say I'm a little worried about the heavy lightning. All of my control boxes are indoors except for one 16 channel that is under my mega tree. I've unplugged the two that are indoors, but I couldn't risk running outside and fiddling with the power to the other box, since I'm not too fond of running in the rain while heavy lightning is going on. I've also unplugged the Cat5 from my laptop. So, my question is: does it help to unplug the power from the controller during a lightning storm or heavy downpour, or will lightning possibly hit it either way? Also, what other precautions could I take for protecting my equipment from lightning strikes? Thanks!

-Taylor

[Texan78]

Nothing you can do really, if lightning is going to hit it, it is going to hit it. Despite what some people might think metal and electricity is not an attractant to lighting. Lightning is attracted to the larger taller standing objects around it. Now with that said, that doesn't mean you can get hit while standing outside or it doesn't hit random objects that are not taller then other objects around it. Just more times then not it will strike taller objects. This is one reason they say don't stand under a tree because it is a tall object and is attracted it lightning, or out in the open field, because guess what. You have just made yourself the tallest object around and a target for a strike.

The thing about a CG+ strike is if it does hit a conductor of electricity such as a metal object the current will travel. So it is not a bad idea to unplug them if you feel unsafe because if your box was to get hit the current would travel through the lines. Mega trees are most likely to be hit, especially if it is the tallest object around. This is why most towers and buildings have ground rods attached to lighting rods to carry the current away if they do get a CG+ strike.

[TaylorFox]

Haha, so I guess having the control box mounted under the mega tree could possibly at least deter the strike... or make it more of a target. (at least the center support is PVC). Have there been a lot of cases where lightning has struck outdoor controllers? Theoretically, what kind of damage should you expect from a lightning strike to one of the controllers?

[Texan78]

Well if it hit your mega tree it would pretty much just blow it up like if you stuck a block of C5 to it and melt it. Since it is PVC the current wouldn't travel and go to your box, but the PVC since it is such a small target you could expect the hangover from the strike to hit your box. If it hit your box it would be a melted heap of plastic. Usually when a strike hits a path of resistance it will stop at that path. Lightning bolts are not as big as one might think. Yea they look impressive in the sky but what you are seeing is the energy these things produce. The discharge around the way of 65 kA positive or negative. The actual size of a strike is only a couple of inches to a foot. If you have other things that are taller that are around your tree you should be ok, PVC is such a small target anyways you should be ok as long as it is not the tallest object around.

This is why all my weather related equipment that is on my roof is attached to PVC.

CC+/- you don't need to worry about. Those are just the flashes of light in the clouds and they don't produce strikes. If you are curious if the are CG+ or CC strikes just turn on your radio to an AM station that is empty and if you hear a sudden change in static you know you are getting strikes. AM freq can detect lightning up to 200 miles.

Is your tree the tallest thing around?

[cmoore60]

My mega tree is 21 foot tall with the star on top. Made out of 1.5 inch black iron pipe. Can we say LIGHTNING ROD?

Not worried. Home owners should cover most.

Chuck

[Texan78]

cmoore60 wrote:

My mega tree is 21 foot tall with the star on top. Made out of 1.5 inch black iron pipe. Can we say LIGHTNING ROD?

Not worried. Home owners should cover most.

Chuck

Yea from the looks of your picture, I would say you have a good possibility of getting "lit up"...

It doesn't look like much in the way of other taller objects around it.

[-klb-]

Actually, attempting to dissipate a hit is only a secondary purpose of lightning rods. The primary purpose is to provide a path to ground so as to dissipate any static charge that would tend to ionize the air, and make it more conductive. This generally has a net effect of making something else that is not grounded a more attractive target, as the wind induced static charge ionizes the air, and makes the air around it more conductive, and thus easier to hit..

[Texan78]

-klb- wrote:

Actually, attempting to dissipate a hit is only a secondary purpose of lightning rods. The primary purpose is to provide a path to ground so as to dissipate any static charge that would tend to ionize the air, and make it more conductive. This generally has a net effect of making something else that is not grounded a more attractive target, as the wind induced static charge ionizes the air, and makes the air around it more conductive, and thus easier to hit..

right, that is what I was trying to say when I said they had ground rods to give it an alternative path to discharge instead of through the object it strikes...

[TaylorFox]

My mega tree is only 15 feet tall, so lets hope the lightning would find the transformer pole on the street first!

[Texan78]

I think you should be ok, the storms we have seen in the south the past couple of days are rare and usually are not this severe. So you shouldn't have to worry about about storms that often with lightning during Dec.