Lightning Safety

[Pat]

Lighning safety is a topic that effects rural types. Here is a something I thought would be of interest. But first this question... In general, there are reminders to stay away from washing hands, taking showers, doing laundry or similar activities when lighning is reasonably likely. With plastic mains, plastic pipe in the ground and house, is that still important (laundry has wires involved but how about just plain water use?)

Summary of Lightning Safety Tips for Inside the Home

1. Avoid contact with corded phones
2. Avoid contact with electrical equipment or cords. If you plan to unplug any electronic equipment, do so well before the storm arrives.
3. Avoid contact with plumbing. Do not wash your hands, do not take a shower, do not wash dishes, and do not do laundry.
4. Stay away from windows and doors, and stay off porches.
5. Do not lie on concrete floors and do not lean against concrete walls.

I can follow the science behind all the suggestions except washing hands and showering if all piping is plastic. Any thoughts?

By the way more folks are killed every year by lighting than tornados or hurricanes and the majority of those are on the telephone when hit. There are nearly a hundred lightning deaths in the US per year and another 300 reported serious injuries. Don't be a statistic!

Pat

[egon]

Pat:
Your car is one of the safest places to be in a lightning storm.

Actually, inside a metal ball would be the safest.

Egon

[Pat]

Egon, True, IF... IF the car is not a convertible or topless, the windows are rolled up and you aren't where power lines , trees or whatever could fall on you.

Rebar in a saferoom makes it into sort of a Faraday cage but you have to stay away from the walls and staying off the floor is good too. I'll be in bed so I'll meet the criteria.

Pat

[Stoneheartfarm]

Pat,

The plumbing may be plastic, but the pump and water hearter usually are not. Lightning follows the wiring to the appliance, jumps to the water and comes back up.

Lightning hit the cabin several years ago. Just about 30 seconds after I came back from the bathroom. The charge followed the wiring to the pump and water heater on its way out. Boy, was I lucky. Could have been 30 seconds later. [img]/forums/images/icons/blush.gif[/img]

Steve

[egon]

Pat:
That's the word I was trying to remember .

Egon

[RobS]

Good topic! Anyone have any info regarding lightning protection for houses? Is it worthwhile or not? I see a lot of older houses with lightning rods but not many new ones. Everyone tells us we should have lightning rods on our house as it is quite tall and sits out in the open. It seems to me though, that lightning rods will only serve to attract more lightning and may actually make matters worse. Thoughts?

[img]/forums/images/icons/smile.gif[/img]

[Pat]

Steve, I shoulda thought of that! Our pump is at the botom of the well and the well house is about 700 ft from house. I have had fuses in the well house blown by lighting but I suspect little or no current flowed to the house. Now the water heater is a bit closer and the pipe runs from it to us are not burried. Maybe I'll have to rethink my actions with thunderstorms in proximity.

If you can hear the thunder, there is danger, even from flashes up to 5 miles or more away.

Pat

[Pat]

Rob, Thre is a wealth of lightning protection information applicable to residential structures. Unfortunately it is not widely distributed. It may be covered in the national building codes BOCA and NEC.

Anyway, properly installed lightning rods reduce the likelihood of a structure being hit by lightning. The sharp points on the rods (small radius of curvature) concentrates thte electric field vector so that it exceeds the ionization potential of the air causing a "brush" discharge. Considerable current can flow through the lightning rods between the air (charged clouds) and the earth. This provides a means of discharging the giant natural capacitor that is formed between the clouds and ground. If you have enough discharge capacity you can drain off the charge as fast as it is generated (in your vicinity) and prevent a lightninig stroke.

As nature can prepare some monster charges and most folks do not (or can not) design for worst case, there is always a distinct possibility that your drainage system will not keep up and your system will be hit by lightning. That is why special care must be taken to install the system correctly as it should be able to safely conduct lighting between cloud and ground via your systems wiring without being destroyed or unduly damaged and remain operational.

Rather large conductors are used. Large radius bends are required to avoid raising the electric fied vector and having the lightning exit your conductor and takes its own path, perhaps destroying a part of the house.

Good lightning protection isn't cheap but increases your personal safety and the survivability of your structure. You might want to check with insurance types regarding discounts, applicable equipment and installation standards. If your house is the tallest thing around your area then it isn't a question of if you will take significant hits it is when.

Some folks haven't seen attractive glossy adds in "Better Homes and Gardens" for lightning protection systems and think them unattractive so they opt to look good rather than be safe. I think they are a great addition to anything remotely resembling Victorian style or farm or ranch style.

Pat

[egon]

Home and barn Lightning Rods used to be a very common fixture. Perhaps the reason not many are seen these days is because of the electrical distribution system. This may take many hits that got to buildings before.

It is not uncommon to have appliances damaged by lightning strikes to the distribution grid. Bottom hole pumps are very susseptible. Many people carry insurance to specifically cover the pump.

Transformors are also frequently blown. Most of the utility company's main equipment can take and reset up to three strikes. Then It's lights out. Farther out on the grid there are fuzes on the line that will blow.

I beleive almost all tall buildings in towns have lightning protection. The CN tower in Toronto gets struck well over a thousand times a year.

Back in Alberta one neighbour about 300 yards away was constantly haveing his transformer and pole hit.

Egon