Lightening Strikes

Jack

Having just read the CSST thread I want to pose a question about equipment replacement/repair after lightening or near lightening strikes. I think a house that takes a hit and has electrical/electronic equipment damage is in most cases not worth repairing and becomes a homeowners insurance claim for replacement. The reason I say this is the board may be fried and the equipment "may" operate after the board or component is replaced but you've had so much energy zipping around the rest of the unit that premature failure of other components may likely require equipment replacement at the owners expense after the insurance claim could have been made.



Don't worry about telling me I'm nuts. I've heard it before. How do you advise customers in this circumstance?

icesailor

Lightning Damage:

You don't need a direct hit to have damage. A lot of damage is caused by lightning and people don't even know they were hit. I've seen where a air handler didn't work properly, Sparky, who is clueless about how controls work and can't quite grasp the wiring of a 4 or 5 way light switch, is clueless when you try to show him that something isn't right. Even after the owner says that 4 years ago, they took a hit and caused THOUSANDS of dollars worth of damage.

Consider this (as I understand it). Electricity always travels at the speed of light. It doesn't matter if it is a 24 volt thermostat wire, 300,000 volt transmission line, or a bolt of lightning. Ohm's Law says that "The higher the voltage, the less the resistance". You can put 1 amp of 24 volt current through a piece of #16 wire and you can put 1 amp od 24 volts through that overhead 300,000 volt transmission tower wire, Don't try sending 1 amp of 300,000 volts through your 16 gauge thermostat wire. Its the resistance in the wire with 300,000 volts and 300,000 amps trying to get through the #16 thermostat wire. The resistance heat will melt the wire and spray the molten metal everywhere.

I've been hit by lightning. I don't know if it was grounding through the transmission system or coming back through the transmission to get to the cloud. All I know was I was between one source (holding on to a 2: well pipe with one hand) and it jumper across my arm to a bonded/grounded cold water pipe.

I now live in the lightning capital of the world. South Florida. Every afternoon, we get rain and lightning. Where I used to live will put the fear of Dog in you during the lightning storms. And so much so that a former fire chief said that he could park a fire truck in a certain area so he could get to the house fire quicker. When you see the flash, hear the "Pffft" and hear the BOOM, all in the same instant in time, you know it was close. Supposedly, if you see a flash and a pause, then the BOOM, it is a mile or more away. Speed of light Vs. Speed of Sound.

In the city I live in, with huge transmission lines a mile away on two sides, and lots of close strikes, with the scariest lightning I have ever seen, I've not seen any electrical damage. I think that the more grounded/bonded structures and transmission lines where you are will give you a safer environment. If you live in some area where you can't get there from here, not so lucky.

Someday, I'll find that photo I've been looking for, for years from National Geographic with the Oak Tree in a field with the main strike hits the upper mart of the tree and hundreds of little lightning strikes (they look like snakes) coming out of the ground.

KC_Jones

Pictures

Either of these the ones you are talking about?

icesailor

Trees:

No, but similar to the one on the left.

The camera was above the ground but below the top of the tree. It was back some and probably done with a high speed camera with a Telephoto lens. The whole photo was in focus. The only way you can get those photo's are with high speed cameras set to run and recycle. If you saw that PBS piece on the Sprites, they showed how it was done. With a camera taking 10,000 frames per second in  G5 Gulfstream flying over Kansas in a lightning storm coming off the Rockies.  So if the human saw a strike, he could replay the last three seconds of video. Reaction time isn't fast enough to catch it otherwise.

Consider this from a crazy old man. When those golfers stand under a tree during a lightning storm and get hit, they almost always have their shoes blown off or they are blown out of their metal cleated shoes, which are burned to the ground. I've never heard that they had their heads blown off. Which direction would a reasonable person think the lightning was traveling?



Maybe I'm unreasonable and jump to my own conclusions. The safest place to be in a lightning storm is usually in your car.

icesailor

Looked everywhere:

I looked everywhere on Nat Geo's photo web site.  I think it might have been in a July 1993 issue on Lightning. That's when I was hit twice in 6 weeks and had suppression installed.

It is somewhat like this one except that a main bolt hits the tree. In 1993, they didn't have the high speed digital cameras they have now. It had to be an "Accidental" shot. One that appeared on the photo. Like all those photographic shots of flying saucers or Bigfoot.



Or maybe Nat Geo chose to not show it anymore because it would scare people. There always Adult size Depends for golfers.



https://www.google.com/search?q=national+geographic+lightning+photos&tbm=isch&imgil=kwDdwV6Cl46GzM%253A%253Bhttps%253A%252F%252Fencrypted-tbn1.gstatic.com%252Fimages%253Fq%253Dtbn%253AANd9GcTeQns5NxaEQF0ER_uHCz1ssoydVVX4t9cUPcSuYZYLtzXapz-qEQ%253B1600%253B1200%253B9ZYY2O3Kqz6quM%253Bhttp%25253A%25252F%25252Fngm.nationalgeographic.com%25252Fwallpaper%25252F2012%25252Fapril-ngm-wallpaper&source=iu&usg=__qTfDp3xig4s_OIyH81MQM33mVcg%3D&sa=X&ei=Lby-U4XoKcSOyASbiYGQCA&ved=0CB8Q9QEwAA&biw=1093&bih=434#facrc=_&imgrc=kwDdwV6Cl46GzM%253A%3B9ZYY2O3Kqz6quM%3Bhttp%253A%252F%252Fngm.nationalgeographic.com%252Fwallpaper%252Fimg%252F2012%252F04%252F07-greece-lightening-exposures_1600.jpg%3Bhttp%253A%252F%252Fngm.nationalgeographic.com%252Fwallpaper%252F2012%252Fapril-ngm-wallpaper%3B1600%3B1200

Jack

And given this,

How do you advise clients?

icesailor

Advice:

If they are having lightning issues, it's not my problem to fix it. I tell them to have a suppression system installed. Its cheaper than a new house or new electrical equipment.

Its not my problem, it's not my fault.

If things don't change, I'm going to call the whole thing to a halt.