Is Your Home Safe From Lightning Stikes?

[pkrv]

Ahhh yes! Good ol' wikipedia...the epitome of accuracy.

Here's a 'real' document about lightning protection. Please note sections 3 & 6.

In short, don't even think about plonking a lump of metal on your roof, which is connected to another lump of metal to the ground unless you really want to go to the trouble & do it right. By not doing it correctly, you could, in fact, cause more problems. Lightning protection is not a simple thing.

Nooooooooooooooooo that was brain melting! I do agree with you I note if you attempt to engage wikipedia and you try to disagree with christian facts you are oddly dismissed (despite empirical proof, particularly on the butchery front). But then again it is an American artefact.

I do oddly recall (from what I was taught) that one of the aspects of a lightning conductor is it supposedly to produced an electrical charge (positive, negative or neutral?) at the tip that actually stopped a lightning strike? - Don't know.

[elkangorito]

Nooooooooooooooooo that was brain melting! I do agree with you I note if you attempt to engage wikipedia and you try to disagree with christian facts you are oddly dismissed (despite empirical proof, particularly on the butchery front). But then again it is an American artefact.

I do oddly recall (from what I was taught) that one of the aspects of a lightning conductor is it supposedly to produced an electrical charge (positive, negative or neutral?) at the tip that actually stopped a lightning strike? - Don't know.

Not quite true.

The Earth (world) is considered to have an overall negative charge (-). The idea of a lightning rod is to divert the transient away from damageable things/areas. It does this by providing a low impedance path to the earth, which has a significantly lower impedance to earth than the electrical path through an antenna mast (for example). As revealed in the posted document, this can only be achieved by carrying out a series of rather involved tests.

Again, a lightning rod on your house is a waste of time unless you are willing to go through the correct & lengthy process to ensure that it will do its' job.

[Naam]

I do oddly recall (from what I was taught) that one of the aspects of a lightning conductor is it supposedly to produced an electrical charge (positive, negative or neutral?) at the tip that actually stopped a lightning strike? - Don't know.

that's correct. a similar principle was used to deter phaser beams during my time when i served on starship Enterprise. i don't know the details though and Scotty is dead. otherwise i would have phoned him and asked for a technical explanation.

[elkangorito]

I do oddly recall (from what I was taught) that one of the aspects of a lightning conductor is it supposedly to produced an electrical charge (positive, negative or neutral?) at the tip that actually stopped a lightning strike? - Don't know.

that's correct. a similar principle was used to deter phaser beams during my time when i served on starship Enterprise. i don't know the details though and Scotty is dead. otherwise i would have phoned him and asked for a technical explanation.

Can't you just go back in time & 'beam scotty up'?

[elkangorito]

....As for lightning conductors melting. I've never seen that and I've inspected quite a few installations that have been in place for many years.

Just a footnote.

I remember, when I was a kid, witnessing a lightning strike about 30 metres from my home. After the storm, I went to look at the area where I thought the lightning had struck. All I saw was something similar to a great lump of rock impregnated glass on the ground. The lightning had melted some of the rocks.

[pampal]

Our 360 KVA transformer was hit by lightning and the lightning rod that we had installed did it's job and the only thing that happened was the fuse on our transformer was tripped.

The lightning rod performed as expected with no damage to any of our appliances/computers at the factory.

[elkangorito]

Our 360 KVA transformer was hit by lightning and the lightning rod that we had installed did it's job and the only thing that happened was the fuse on our transformer was tripped.

The lightning rod performed as expected with no damage to any of our appliances/computers at the factory.

All well & good but do you have the secondary 'required' protection for your factory?

[pkrv]

I do oddly recall (from what I was taught) that one of the aspects of a lightning conductor is it supposedly to produced an electrical charge (positive, negative or neutral?) at the tip that actually stopped a lightning strike? - Don't know.

that's correct. a similar principle was used to deter phaser beams during my time when i served on starship Enterprise. i don't know the details though and Scotty is dead. otherwise i would have phoned him and asked for a technical explanation.

I'm sorry I can't resist - Klingons on the starboard bow Starboard bow...

[astral]

This is my neighbour's electricity meter after a lightning strike.

[elkangorito]

This is my neighbour's electricity meter after a lightning strike.

Notice that most of the damage seems to be confined to the cables in close proximity to the meter, which is most likely due to the increased impedance at the meter connections.

This damage may have been greatly reduced or even negated IF HRC fuses were used to protect the incoming supply & they were placed BEFORE the meter. Doing this is standard practice in most other countries that have high prospective fault currents. It just so happens that Thailand has relatively high prospective fault currents but using HRC fuses here is an alien concept.

Of course, the destruction of the meter may have served to protect the consumer wiring/equipment - did it?

[astral]

Of course, the destruction of the meter may have served to protect the consumer wiring/equipment - did it?

Sorry, I am not sure.

Certainly the electricity company did not care,

they just bypassed the meter and kept on billing the guy

at his previous monthly rate.

I believe the landlord was expected to pay for a new meter.

[pampal]

Our 360 KVA transformer was hit by lightning and the lightning rod that we had installed did it's job and the only thing that happened was the fuse on our transformer was tripped.

The lightning rod performed as expected with no damage to any of our appliances/computers at the factory.

All well & good but do you have the secondary 'required' protection for your factory?

I don't understand what you mean by "secondary required protection"?

[elkangorito]

Our 360 KVA transformer was hit by lightning and the lightning rod that we had installed did it's job and the only thing that happened was the fuse on our transformer was tripped.

The lightning rod performed as expected with no damage to any of our appliances/computers at the factory.

All well & good but do you have the secondary 'required' protection for your factory?

I don't understand what you mean by "secondary required protection"?

Usually, in installations that are affected by "down time" (factories etc), it is sensible to install "secondary" lightning protection. This usually means the installation of MOV's (Metal Oxide Varistors) at appropriate locations.

"Primary" protection is not just a lightning rod. It normally requires the installation of a completely "earthed" copper or stainless steel grid upon the outside of the physical building. When these 2 systems are combined, they are very effective in preventing lightning damage to electrical infrastructure.