Lightning Protection

There is an interesting one, for me at least. I am down in Ocala, Florida for a very short stay developing a race horse registry for unwanted animals and yes it's lousy pay and worse work. I am not missing winter but reality returns all to soon. So here is the question... lightning protection.

The lady on this farm lost her files last summer due to yet another lightning strike. Of course, there are off site backups but that is not the real question. How do you protect a farm that has lost many cows to lightning, had a 22' RV literally explode in a strike and has a dozens of in house horror stories etc.etc. We don't understand real electrical storms up in the NE. This truly is planet leading electrical hell down here. She has all the lightning protection in the world on building roofs and maintains them too but still has major damage every summer. I was struck in Chester some years ago and put Primax protectors on all the buildings but we mostly have baby storms. Those little high joule power strips are no good down here, the locals in Ocala say live with it, nothing protects you. I can't accept that, so guys, what is the best lightning protection/power surge systems for residential electrical power circuits (Point-of-Entry Protector, or single circuit to run computers) out there?

Only fool proof solution for Registry----NOTEBOOK and PEN--damn, how archaic Lazy ass horse people!!! As for man against Mother Nature???? how's that been workin out for us--maybe Russia should chime in here

Thats interesting... As for protecting a computer, I would have a battery bank to power it during electrical storms so I could completely disconnect it from the grid.. Also make internet connection via wireless router so it wouldn't be connected physically that way as well.

As for the cows, maybe steel cables could be strung over the pasture so they would likely take the strike.. Similar to the one strung over the space shuttle's launch pad.

As I understand lightning protection in principal, the system required for building protection needs to create a path to ground adequate to drain the potential faster than it can grow, there by avoiding the build-up and pending surge. Sounds like this is not practical given the magnitude of the potential present.

Now, as far as utility supplied electrical services for buildings are concerned, look into whole house lightning protection at the service entry point.

Here is a starting point on this:
whole-house-surge-protectors

coalnewbie wrote: I can't accept that, so guys, what is the best lightning protection/power surge systems for residential electrical power circuits (Point-of-Entry Protector, or single circuit to run computers) out there?

Read and understand the IEEE technical document I referenced in this post.

Calling all Electricians!!!!

I considered installing a whoe house surge protector (SPD) at the main panel when i wired our house (new service) but ultimately did not.
They do offer good protection against power spikes or surges (most power surges are created WITHIN the home itself)...but the truth is basically nothing can guarentee protection against a lightning srike....or near strike.
The truth is that lightning is simply to powerful to completely channel to ground entirely. ( key word-entirely)
SPD or UPS devices will offer protection to home electronics...but mostly against power surges ( from the grid...or from the home) but not always from a lightning strike.
Lightning can carry over 100 000 amps ( or more)....so even if a system could provide 99% protection against that much energy...there is still 1000 amps available to be distributed through out the structure.
Most likely the residents there "learn to live with it " as you stated....is because they simply havent developed a system for the residential market that works 100% of the time.
UNPLUGGING all devices would be the guarentted method....but a person would have to be home whenever the threat for lightning arises...

Yanche wrote:

coalnewbie wrote: I can't accept that, so guys, what is the best lightning protection/power surge systems for residential electrical power circuits (Point-of-Entry Protector, or single circuit to run computers) out there?

Read and understand the IEEE technical document I referenced in this post.

Calling all Electricians!!!!

This may be that document referenced...http://www.lightningsafety.com/nlsi_lhm/IEEE_Guide.pdf

Snippets from that document:
Something simple as improperly wired outlets will not allow protection in any case.

The effectiveness of this protection system depends on the integrity of the
building wiring. A good surge protection system installation should include
testing of all the receptacles to be used, for correct connection of the line, neutral,
and ground. This should be done using a tester which can detect interchange of the
neutral and ground connections, a common problem. Incorrectly wired
receptacles can often appear to function normally, but may not allow point-of-use
protectors to function properly.

Higher level of protection for higher lightning areas.

For residential or light commercial locations, a surge current rating of 20 kA to
70 kA (8/20 μs) per phase should be sufficient. Installations in high-lightning
areas should use SPDs with higher surge current ratings, in the range of 40 kA to
120 kA, in order to provide a longer service life and higher reliability. The
recently revised NFPA 780-2004 Lightning Protection Standard requires a 40kA
withstand level for SPDs used at the service entrance.

Lots of good info, read the document...

Two-stage protection, where an upstream SPD takes the major surge current and a
downstream SPD protects the equipment, is the best protection for equipment.
Unless the downstream SPD is very close to the upstream SPD, the surge limiting
voltage of the upstream device will have little impact on the final voltage seen by
the load after the second SPD has limited the surge remaining from the first SPD.

From what I understand, if there are too many grounds in the ground from the lightining rods, that's worse than not having them at all. Instantly fries everything. I think I recall reading that in that post Yanche made in that thread he linked from a while back ....

Wow, now I have some serious reading to do and I have realized two things. There are some really smart people here on this board and freetown fred needs to check his flu for fume leaks...... HAHAHAHAHHAAH I slay myself. I like the theory of multiple grounds screwing things up and will investigate that one some more.

We all know, or at least should know, that the electric service panel is connected to earth ground. That connection can be via a ground rod, water pipe or metal well casing. Ideally that's the only place in your home where should be a conductor connected to anything electrical comes into your home. Let me give an example, one that took me years and many equipment failures to figure out. Cable TV. When cable TV was run on my street the cable company offered free installations. It was done by contractors in the cheapest way. Where's your TV? In the living room. We'll run the cable right through the wall there. OK? They did. Ground rod and lighting protection device outside right there on the wall right behind the TV. Is this OK. NO, NO, big mistake. There are now two electrical earth grounds in the house, the cable TV coax and the electric service entrance. The cable TV coax gets connected to your TV, cable modem, router, etc. This effectively connects the two earth grounds together, inside your home. Now, along comes a lighting strike, one that doesn't even have to hit your home. Big, big, really big currents are flowing in the earth. They find their way to your two earth connected grounding rods. It's highly unlikely the exact current will be at each grounding rod. If there is a different ground current in each, a current caused by the difference in potential will flow. Where? In your house. In the wiring that connects them. What's that? The cable TV coax shield, the green wire in all your electric outlets, the white neutral in your circuit breaker panel, etc. This flowing current, if it's large enough, and in a lighting strike it will be, will cause a voltage difference in the different ground wiring circuits. What happens? Puff, at the weakest point of connection, inside your electronics. Your TV, cable modem, VCR, etc.

The solution? One and only one point where earth ground enters your house. This means all, electric power, cable TV, satellite TV, telephone land line, electric sub-panel feeds to out buildings, wiring to your submersible water well pump, enter your house at the same physical point. AND all the lighting protection devices associated with each service, i.e. electric service bonded neutral, cable TV lighting protector, telephone company provided lightning protector, satellite TV dish ground, etc. use the same single ground rod circuit. All this is difficult to do. But after I did it, I stopped burning out TV's, cable modems, answering machines, well pumps, etc.

THINK what you have. Draw a schematic diagram of your grounding circuits. THINK of each place a metal conductor, that's connected to your electric devices comes into your home. There's a lot. Propane tank copper line? It's connected to your dryer's electric ground. Central A/C? The copper refrigerant lines go outside. It's connected to the condensing unit's electric ground. Etc. Good luck.

I'm not sure I understand your post completely Yanche. But I agree there should be a single ground source. The other metal in your home such as copper plumbing, gas lines, etc. should be bonded. Grounding and bonding are widely misunderstood.

coalkirk wrote: Grounding and bonding are widely misunderstood.

Amen...I see this a lot, as I am in the electrical trade.

McGiever wrote:

coalkirk wrote: Grounding and bonding are widely misunderstood.

Amen...I see this a lot, as I am in the electrical trade.

....theres actually a difference between earthing and grounding as well.. .Confusing the issue even more

coalkirk wrote: I'm not sure I understand your post completely Yanche. But I agree there should be a single ground source.

Bottom line is always about where the current flows. Voltage is only a symptom of current. Damage occurs when that current enters on one path while simultaneously exiting on another.

Another example of how death occurs. Lightning strikes a tree. Maybe 20 feet away is a cow. The cow is killed by a direct strike. How can that be? Lightning struck the tree?

Lightning is a current that flows simultaneously in a path from the cloud to earthborne charges maybe 5 miles distant. Does lightning cross the sky to get to those charges? No. The shortest electrical path might be 3 miles down the tree and four miles through earth.

The cow was 20 feet away. So lightning from the tree entered on the cows hind legs. While exiting via its fore legs. Cow, directly in that lighting current path, was killed.

Protection is always about the incoming and outgoing path. A single point ground means both incoming and outgoing path do not exist. A golfer with feet together also does not get killed like a cow. A barn must be surrounded by a buried ground wire so that cows inside are only standing on a single point earth ground.

In every case, protection is about how that current gets from the cloud to distant earthborne charges. Protection is ALWAYS about connecting that current on a path that is not destructive. Others have posted good recommendations based in those well proven concepts.

Protection from lightning is so well understood that damage sometimes may be called a human mistake.