Lightning Protection

[buckeye]

As many of you know, my wife and I are in the midst of building a new house on some property we bought last year. Where we are building is on top of a small hill that is nice and flat on top. Howver, there are no trees nearby. We will plant some nice trees once we are there.

On Sunday when we were walking the land and looking at where to exactly put the house, my wife brought up a question about lightning. Since we will be out in the open, what type of lighting protection should we have? Does anyone in the group have experience with installing lightning rods? We are worried about our appliances and electronics mostly, but also about the house in a worst case. Any input would be most appreciated.

 

[gws]

Lightning rods are only good if installed properly and maintained. You need a good path to ground and it needs to be as straight as possible. This means straight down fromt he peak of the house. This is often where then problem comes in because (depending on the house) this is not visually appealing. People want the cable to follow the roof line.

The thing to remember. While lighting rods will help to reduce the static discharge from the house it will not eliminate it. It also doesnt attract lighthing that might hit.

If lighting does hit there is NOTHING you can do to stop it. No gizmo or gadget is going to stop a direct strike.

Good insurance is the best protection after the lightning rods. Maybe even a lighting rider.

 

[heehaw]

i maintain a lot of equipment sitting on the top of mountains, with 100-300ft towers; the lightning protection equipment out there is a lot better than it was 10 years ago; panamax is the primary protector manufacturer i use; just bought some 350va uninterrupable power supples from staples to put on some of the equipment..$50..or a 50va for $70; i had my tv knocked out 3 times from lightning between 86-92; i started unplugging everything when a storm got close; then i put in a satellite system, with a panamax protector for the tv antenna, dish, power and phone line..i installed this in 96, and haven't unplugged anything since, with no problems..even the plug in strips from wallyworld with protection on all lines work well..
heehaw

 

[StoneHeartFarm]

Here's a link for a surge arrestor designed to attached directly to a Square D HOMELINE load center (breaker box). Don't know how well they work, but I found this site awhile back.

<A target="_blank" HREF=http://www.nooutage.com/hom2175s.htm>http://www.nooutage.com/hom2175s.htm</A>

SHF

 

[JoeR]

Living in Central Florida has exposed me to some intense lightning. If you use lightning rods, make sure they are connected to a "common ground." Also, make sure the house ground is part of the network ground. I learned this from experience. I had my TV antenna tower connected to a ground rod next to the tower. Lightning hit the tower and came through the house looking for the house ground. I received about 1,500 dollars in damage. The house ground had a different ground potential than the tower ground which caused the voltage difference between the house ground and tower ground during the strike. Current then travelled between the two points which means it went through the house wiring... What a disaster. I then ran a number 4 solid copper wire between the two ground rods to correct the problem. A year later lightning hit the tower again, and did not do any damage inside the house!!! The lightning did destroy my TV amplifier that was connected to the antenna.

Other types of damage I have seen have been from other points of entry into the home. The power lines are one big one since they are easy lightning targets, and the other big culprit is the telephone line. A nearby lightning strike can induce a large static charge onto the phone or power line, which will send a nice spike into your appliances or computers. It is best to eliminate these transient voltages prior to entry into the home. Otherwise, you may spend more money putting individual protection on each piece of equipment.

The Square D arrestor is a good idea to install into your power panel. It will shunt any voltage greater than 180V to the neutral. The phone company has an MOV that they can install at your network interface point, which will eliminate any transient voltages before it enters into your household phone wires.

The whole idea of lightning rods is to dissipate the static leader charge before it strikes. The second use of the lightning rod is to give all the energy a safe path to ground.

Overall, nothing can survive a direct hit, but you are more likely to encounter the transient voltage issues of nearby strikes. In Florida the average lightning bolt travels 3 miles to earth, the heat generated is hotter than the sun, and it burns oxygen o2 into ozone o3. After travelling 3 miles, a little air gap component of 3 inches would not stop the lightning from hitting its target.

Joe

 

[StoneHeartFarm]

You know, I've always wondered what kind of lightning protection NASA uses? Must be pretty good stuff if it can protect a big steel tower, eighty-five trillion dollars worth of rocket and enough fuel to blast a fair sized lake. Having a million gallons of hydrogen under my seat I think I'd insist on some safety devices.

SHF

 

[JoeR]

SHF,

You know they spend a bundle on lightning protection!! NASA has concluded that you can have faint lightning strikes with just a small cloud! You don't need a big storm to have static discharge... Just a cloud!!

Trivia: Disney World had some lightning protection... When they first built the Magic Kingdom, they installed the Skyway ride. This was the cable cars that went overhead from the edge of Fantasy Land/Frontier Land to Tomorrow Land right next to Space Mountain. Whenever a storm was near they would shut down the ride. Well, the large steel cables above, acted like a giant metal blanket across most of the park which created lightning protection. Someone in the late 60's envisioned this ride as lightning protection too. I don't know how well it really worked, but it sounded like a good idea.

The Skyway ride has been removed some time ago... So let's see how many things/people get hit by lightning... Oops, we will never know!! Since Disney owns ABC, and controls what information leaks out to the general public.

Joe

 

[Hillbilly]

Buckeye,
There used to be a lot of lighting rods installed on houses,I do not see this as much of a common practice today. Not to say it is a bad idea to have lighting protection,but I have wondered before why you do not see lighting rods on newer houses(at least not where I live). You know what I mean?

 

[poorboy]

Seems like I remember reading or hearing somewhere where the lightining actually comes halfway from the ground instead of actually striking the ground.

Anyway stay off the corded phones please. I have had 2 wicked blows this way. Once serious enough for a trip to the ER. Seems that the juice run overabout 10 inches from the phone and grounded itself to the light switch while blowing oout a nice little trench in the sheet rock. I never knew my head could hurt so much. Live and learn, and if you get past the second time follow religiously what you have learned.

Patrick

 

[ewoss3]

actually for high end equipment that is centrally located we use an ADC ups unit($72). this works really well because most of them are being built with 4-6 plugs plus a telephone plug. I located one in the living room and one in the computer room. the rest of the phones and appliances are protected with semi-good power strips. The benefit to this is that all these product come with a warranty that will allow you to replace anything that was damaged, without having to place it on your homeowners policy.