Lightning protection system on building - increased risks
Lightning protection system on building - increased risks
(OP)
Hi!
Does lightning protection system on building increase the chances that this building will be hit by a lightning compared to this same building without lightning protection system? Some people say that it does and some that it doesn't. What is correct?
If this is not correct forum to post this can someone recommend where to ask this question?
Thanks!
Does lightning protection system on building increase the chances that this building will be hit by a lightning compared to this same building without lightning protection system? Some people say that it does and some that it doesn't. What is correct?
If this is not correct forum to post this can someone recommend where to ask this question?
Thanks!






RE: Lightning protection system on building - increased risks
Charge builds up in objects below clouds, creating a voltage gradient. The charge build up doesn't have to have low resistance path because it is a slow process (relatively) and doesn't result in a large current until the air breaks down and the stroke occurs.
RE: Lightning protection system on building - increased risks
Link to article: http:/
Now, who is right?
RE: Lightning protection system on building - increased risks
RE: Lightning protection system on building - increased risks
Jimi Young - civilian
184th CES/Electrical Shop
Ks Air Nat'l Guard
McConnell AFB, KS
RE: Lightning protection system on building - increased risks
RE: Lightning protection system on building - increased risks
RE: Lightning protection system on building - increased risks
RE: Lightning protection system on building - increased risks
Following the strike, the metal structure may conduct a somewhat higher current. But the damage will depend on I^2R and the R of the wooden pole is much higher, so it will dissipate more energy. Even worse, once the current heats any moisture within the wood to the boiling point, it flashes to steam and breaks the structure. That's why lightning struck trees 'explode'. Metal just gets hot.
RE: Lightning protection system on building - increased risks
Now if the pole conducts the charge to ground then their is no lowering of the electric field gradient and the arc is more likely to start there.
same consideration for a wooden building with no lighting protection.
BUT the wooden building if struck is on fire, lighting protection is always recommended.
RE: Lightning protection system on building - increased risks
The accumulation of opposite charge in a pole is not a fast accumulation where a large amount of current (dq/dt) would be affected by the resistance of the pole. It is a slow buildup that occurs as the cloud passes over the earth. The amount of charge accumulation does not depend on the pole material. The charge in the earth and the pole, being of opposite polarity to that in the cloud, increases the voltage gradient, it does not lower it.
RE: Lightning protection system on building - increased risks
RE: Lightning protection system on building - increased risks
RE: Lightning protection system on building - increased risks
RE: Lightning protection system on building - increased risks
RE: Lightning protection system on building - increased risks
RE: Lightning protection system on building - increased risks
RE: Lightning protection system on building - increased risks
RE: Lightning protection system on building - increased risks
One more question, when large current flows through down conductor in LPS on the building it makes large voltage drop, so we have very high voltage at the down conductor. Why don't we have little strikes between down conductor and wall or roof? Or why doesn't current flow from down conductor through installation elements to wall, because current would flow through the wall if there was a strike and no LPS?
RE: Lightning protection system on building - increased risks
But you have to keep in mind that you are trying to funnel a lot of electrons into the grounding system and sometimes some of the electrons get away. A bolt of lightning that traveled 20,000 feet **through the air** can find a lot of ways to get to ground.
You might do some Google searches for NASA research papers regarding lightning protection. At the Cape, they get a tremendous amount of lightning; they have a lot of valuable things to protect, including spacecraft, and they seem to do a really good job of protecting it.
RE: Lightning protection system on building - increased risks
RE: Lightning protection system on building - increased risks
If we sad that lightning doesn't care metal or not why this little lightning (static discharge) does?
RE: Lightning protection system on building - increased risks
RE: Lightning protection system on building - increased risks
RE: Lightning protection system on building - increased risks
RE: Lightning protection system on building - increased risks
Simple questions and simple answers will not lead to much understanding. There is a chapter on static electricity in every physics text, and there are free on-line video courses.
RE: Lightning protection system on building - increased risks
RE: Lightning protection system on building - increased risks
RE: Lightning protection system on building - increased risks