Lighting Arrester and Lightining Rod

Help yourself:

Lightning rod - Wikipedia, the free encyclopedia

Lightning arrester - Wikipedia, the free encyclopedia

Obviously, I know more about it than you do.

All right then... thank you so much...

Nonsense. How many church spires have two lightning conductors (rhetorical question - NNTR)?

Actually, I've seen church spires with at least four large lightning conductors, and additional conductors at the end away from the spire. If I recall correctly, both Notre Dame in Paris and Il Duomo in Florence are like that. Additional protection was added to Il Duomo after a lightning strike knocked down the original ball on top of the dome.

But Legolaz didn't say two lightning conductors. He indicated a lightning arrester in addition to the lightning rod. Lightning rods and lightning arresters provide different kinds of protection.

Who says two? Some church has its own lightning. (Joke only)

It is never good to have two separate grounding rods especially if you have lots of electronic equipment, the code said, it'll create ground loops and create interference. I do not know.

DKwarner is right. I suggest OP should do a further study.

Thanks a lot....

Hire a competent company that installs lightning rods and lightning arresters!

Lightning (surge) arrestors are normally used to protect electrical circuits from high voltage incidents.

Lightning rods connected to a low impedance ground grid are normally used to protect structures so that the lightning current during a strike follows the lowest path of resistance from the rod(s) to and through the grid to earth instead of through the structure and all of the contents.

I suggest you consider specialized equipment that when mounted at a specific distance above the highest part of the structure creates a neutral ion cloud above the area preventing or at least greatly reducing lightning strikes to the area.

As Lyn and others have stated; It is in your best interest to entertain employing a reliable, competent specialized agency to look at the site and provide their recommendations.

I would entertain at least three (3) such specialized providers to perform an evaluation of your site then thoroughly review and compare contents of the reports to identify which direction you need to go.

Those so-called radioactive tipped ionizing earth terminals that "... creates a neutral ion cloud above the area preventing or at least greatly reducing lightning strike..." have been thoroughly debunked, actual tests have shown that they actually increase the probability of a direct stroke being drawn to it.

Do you actually believe that anything can redirect a force of nature that can be charged from 100 million to 1 billion Volts, with a current as high as 100,000 Amps, can contain a billion to a trillion watts, and has traveled 35-45,000 ft through air, at a temperature from 18,000 to 60,000 degrees Fahrenheit, in the last few feet of its travel? Granted it's for only 10-200 microseconds, but 5 billion Joules has to be go somewhere; conduction and suppression is how you minimize the potential destruction.

Why can't you design a system which eliminate building up of charges in a given small ares like top of building.

Because that's exactly what a lightning rod is designed to do. It is the site of a preferential strike.

I believe that a lightning rod can also "spray" charge into the space above it, at least partially reducing the dV/dY, and delaying somewhat the timing of the strike, or conceivably even preventing it in a few cases.

I once was on the very top of a small but very pointed mountain (Bishop's Peak, near San Luis Obispo, CA), and observed St. Elmo's fire exiting the tip of my raised finger. I had been in that spot for most of a half hour, testing radio reception, when I suddenly noticed the St. Elmo's fire at the tips of my FM dipole antenna. When I lowered the antenna and raised my finger, I saw about two inches of "fire" above the tip of my finger. I thought it wise to make a rapid retreat, to a spot under a large boulder perhaps a hundred yards away and down the mountain. Lightning did indeed strike the very spot where I had been standing, only a few minutes later. I've always wondered whether that St. Elmo's fire delayed the lightning, or whether I was just plain lucky to get down in time...

"I suggest you consider specialized equipment that when mounted at a specific distance above the highest part of the structure creates a neutral ion cloud above the area preventing or at least greatly reducing lightning strikes to the area."

Okay, now I'm confused, and it's NOT due to Decaf this morning.

What, exactly, is a Neutral Ion? How does it differ from a Positive Ion or a Negative Ion?

Lightning rod and arrestor are components in a lightning protection system. You should ask an experienced engineer what type of protection is ideal for your building.

http://www.electrical-installation.org/enwiki/Building_protection_system

Even the recognized lightning expert who was a prof at a Florida university is changing the existing paradigm. However, a few considerations: A charge dissipator needs to be 300 meters above the protected object, doable but practical? The Lightning system provide a cone of protection of about 45 degrees over the object. Lightning arrestors may provide protection to some electrical equipment but additional protection via a Farraday cage would be needed for electronic equipment. Lightning never strikes twice is the most incorrect saying ever. My recommendation to retain a qualified consultant with a great reputation in a state like Florida where lightning is a common hazard.

Perhaps you can name or provide a reference to "...the recognized lightning expert who was a prof at a Florida university...", or provide a reference to the "...300 meter..." height that you state. The 45º cone of protection is a well known GEP (Good Engineering Practice) based upon correlating actual strike frequency and the observation that there is a 50/50 (not Zero) chance of a strike on either side of the cone.

From the NLSI (National Lightning Safety Institute):

Thank you for that RAM

There is a normal electric current that issues from the ground as a vertical flow of electrons. In dry air this current produces a vertical voltage gradient and consists of electrons streaming upwards.

that is about 100 volts per meter. You need a very high impedance voltmeter to measure this, on the order of 10,000 megohms. Air is an insulator, but from time to time this vertical voltage can increase to the point where lightning - which is a spark in the air, occurs.

This can be between two clouds, one + and the other -, to from the ground to the charged air mass. When a large charged cloud travels across the earth (the charge is accumulated by charge transfer mechanisms, by rain, snow or dust) a similar cloud follows along the earth below. The electric field can reach a high enough intensity that it can induce what is called a stepped leader, which is an incipient bolt of lightning.

Once the lightning occurs, it is usually complete in 20-30 microseconds, although the stepped leaders can take a little longer.

AT the time of the strike, a current of 10,000 to 50,000 amperes is passed to ground in that 20-30 usec.

As this passes, the inductance of the conductor it passes through causes a delay in passage. This delay causes the high voltage to seek other conductors, because adding parallel inductors reduces the inductance, which passes the lightning bolt to ground more rapidly.

If the lightning strikes a tree, and golfers, cows etc. seeking shelter under a tree become parallel conductors and a portion of the current passes through them. This is often fatal to the cows and golfers.

If the lightning strikes your house and goes to ground via the wiring and your equipment, it often heats the wire to the melting point = fires, and can ruin all semiconductors, fuses, washing machines etc.

So to protect your stuff, you place sharp pointed conductors on the high points of the roof and the eaves. From each of these a large conductor is rund directly down to a coppered ground rod driven 6 feet into the earth, with copper sulphate placed in the hole to add ionic conductivity. (drive in a one inch rod 2 feet, pull it out, our in 1/2 pound of copper sulphate, then drive to the 6 foot level..

As you see a common peaked roof house will have 9 lightning rods. One at each end of the peaked roof and one in the middle, and the eaves will have one at each end and one in the middle. More roofs = more rods.

You also need to have a lightning bypass on the incoming power to the house.

In addition, each thing you plug into it must have it's own lightning protection. This is usually aferrite lightning blocker. read a few of these.

TV sets are quite sensitive, and each antenna needs it's own lightning protection.

I only go into this so deeply because you state you live on a mountain.

People in your position often unplug all electronic equipment and TVs etc, when they leave the house and when they sleep.

You will have to determine the level of aggravation you wish to go through to avoid the huge expense of wrecked equipment.

oh thank so much sir... i've learned so much from your information and opinion... you're truely indeed a great help to the needy...