Lightning Strike.

[sometime]

Yesterday once again the clouds went black and the thunder and lightning started, on its third strike it decided to select a tree four meters from our perimeter wall, the strike then carried along the ground from the tree up the wall, anything screwed to the wall near the rebar was blown off or ruined including starter and relay for bore hole pump, pool salt chlorinator panel and various sockets.

Next day we had a lightning conductor fitted to the house.

We were lucky; consider fitting a lightning conductor to your property.

One thing eerie about this is the lighting went up the wall exactly where one hour before I had just buried our dog.

[WorldwideALOHA]

Very Lucky it didn't carry through any of your interior wiring. Could have blown out just about everything...

Aloha

[stgrhe]

To protect the properties here in Thailand from lightning strikes should be a top priority matter. Ground lightning is an electrical discharge between a thundercloud and the earth. The purpose of a lightning protection system is to provide a good path from the high point of an object to the earth, preferably on the outside of the building. Lightning can cause damage from a direct hit to a structure and it can cause transient surges in wiring leading to buildings. A properly installed lightning protection system should protect from both sources of lightning damage.

Lightning protection for a building should include air terminals (lightning rods) on its highest points, properly sized and installed connecting cables, and a grounding electrode system that makes low resistance connection to the earth. For lightning protection, the building's electrical system must have good grounding and be connected to a separate grounding system. In addition, a surge arrester connected to the home's electrical wires entering the building helps prevent surges from entering that would cause damage to appliances and equipment. Air terminals should extend a minimum of 25 cm above objects they protect. An air terminal should be installed on all high projections. For continuous roof ridges, air terminals should be spaced 7.5 m. The diameter of an air terminal should be no thinner than 18 mm. When installed on a flat surface, the height should be increased to 30 cm but not to exceed 65 cm.

Note that without s surge arrester inductive current may cause a fire to the inside electrical installation even if the property is protected on the outside. The lightning strike is then also likely to damage all computers, TV's etc. in the rooms near the connecting cables.

A grounding connection to earth should be provided at diagonal corners of the structure. Larger buildings should have additional grounding connections to the earth. A grounding connection to the earth every 30 m along a building is recommended. A main wire should be run from the earth ground on one corner, over the building connecting each air terminal and terminating at the other earth ground. If the building is served with a metal underground water piping system, it should be connected to the lightning system grounds. The electrical system ground should be connected to the lightning system grounds. If ground rods are to be used to make the connection to the earth, standard ground rods are 3 m in length. Ground rods should be driven to their full depth and a wire attached with a suitable clamp for direct burial. It is recommended that each earth connection consist of two ground rods spaced at least 3 m apart.

G.

Edited September 15, 2008 by stgrhe

[Crossy]

The electrical system ground should be connected to the lightning system grounds.

Stgrhe, are you absolutely certain that this is correct. I've always understood that the two systems should NOT be connected and that their rods should be as far apart as practical. Any link should be via a TEC (Transient Earth Clamp) to minimise the possibilty of side strikes although I doubt that this would be necessary in a domestic situation. Structual steel SHOULD be bonded to the lightning protection system.

During a strike the potential at the ground rod can rise to many hundreds of volts, not a nice thing to be shoving up the ground pin of your delicate home-theatre.

Edited September 15, 2008 by Crossy

[stgrhe]

The electrical system ground should be connected to the lightning system grounds.

Stgrhe, are you absolutely certain that this is correct. I've always understood that the two systems should NOT be connected and that their rods should be as far apart as practical. Any link should be via a TEC (Transient Earth Clamp) to minimise the possibilty of side strikes although I doubt that this would be necessary in a domestic situation.

During a strike the potential at the ground rod can rise to many hundreds of volts, not a nice thing to be shoving up the ground pin of your delicate home-theatre.

Jesus, thanks mate, it appears that a NOT is missing! Ther should of course be two separate grounding system with at least one rod each.

Sorry for that mistake of mine!

G.

[Naam]

1. The electrical system ground should be connected to the lightning system grounds.

2. I've always understood that the two systems should NOT be connected and that their rods should be as far apart as practical.

1. = absolute bull.

2. = that's how it's done in my country and my home in Thailand.

p.s. i apologise that i exist

[Naam]

During a strike the potential at the ground rod can rise to many hundreds of volts, not a nice thing to be shoving up the ground pin of your delicate home-theatre.

multiply that possibility by 10 Crossy.

[Crossy]

During a strike the potential at the ground rod can rise to many hundreds of volts, not a nice thing to be shoving up the ground pin of your delicate home-theatre.

multiply that possibility by 10 Crossy.

I count in Troll, "one, two, many, lots", so it should be "lots of hundreds of volts"

I see that Stgrhe has spotted his deliberate error

[Eastcoast]

Naam, as you are based in Pattaya can you recommend people to check out my property regarding lightning protection? I'm also in Pattaya. Pretty sure that the house electrical system is fine but after the lightning last week I would like an opinion by experienced people on if I need improvements.

David

[Lite Beer]

Being a complete electrics dummy. I researched a bit about lightning protection.

I rather gather that if it is not done 100% correct it can make things a whole lot worse.

Looked a bit complicated to me.

[Naam]

Naam, as you are based in Pattaya can you recommend people to check out my property regarding lightning protection? I'm also in Pattaya. Pretty sure that the house electrical system is fine but after the lightning last week I would like an opinion by experienced people on if I need improvements.

David

David, i used one expert to protect my wiring but that is not a 100% percent protection as the strike can come through a phone line (had that case two years ago when a strike fried a modem/router and two motherboards). in addition i used my electrician to set up next to my home a properly grounded 9m high metal pole with a copper rod which drew already two strikes without doing any harm to my home. reason for this was that another strike in 2006 fried three sat-receivers and both LNBs of my sat-dishes which are fixed on a lower pole only 2 meters away from my "lightning rod".

you are welcome to have a drink in my home and take a look at my setup. after that it is up to you to decide whether to use those chaps i used. i can wholeheartedly recommend them.

edited: "with a copper rod" should read topped with a copper rod and grounded with a copper rod both rods connected with a THICK copper wire. and when i talk about a copper rod i mean a copper rod and not usual freaking steel rod which is electroplated with a copper thickness of 1/zillionth of a millimeter that can be licked of by a dog in a minute or two

Edited September 15, 2008 by Naam

[Eastcoast]

Naam, as you are based in Pattaya can you recommend people to check out my property regarding lightning protection? I'm also in Pattaya. Pretty sure that the house electrical system is fine but after the lightning last week I would like an opinion by experienced people on if I need improvements.

David

David, i used one expert to protect my wiring but that is not a 100% percent protection as the strike can come through a phone line (had that case two years ago when a strike fried a modem/router and two motherboards). in addition i used my electrician to set up next to my home a properly grounded 9m high metal pole with a copper rod which drew already two strikes without doing any harm to my home. reason for this was that another strike in 2006 fried three sat-receivers and both LNBs of my sat-dishes which are fixed on a lower pole only 2 meters away from my "lightning rod".

you are welcome to have a drink in my home and take a look at my setup. after that it is up to you to decide whether to use those chaps i used. i can wholeheartedly recommend them.

edited: "with a copper rod" should read topped with a copper rod and grounded with a copper rod both rods connected with a THICK copper wire. and when i talk about a copper rod i mean a copper rod and not usual freaking steel rod which is electroplated with a copper thickness of 1/zillionth of a millimeter that can be licked of by a dog in a minute or two

4 strikes in 2 years?? Think you need to move, not get lightning rods!!! Thought lightning never strikes twice...... I've lived here for 12 years and never had any strikes on any of my homes. Do you think that the pole for the sat-dishes actually attracted lightning? I don't have any pole as the satellite dish is on a low roof. If I install lightning rods etc maybe it would make my house a target!! My house is over 11m high at the peak of the roof. Would the lightning rod need to be higher? Worried if I put up rods etc then I may be zapped instead of being bypassed. As my house is right at the highest point on Pratumnak Hill I may be a sitting duck.

Appreciate the offer to tour Villa Naam and check your system. May send you a PM but will make sure it's a sunny day with no cloud cover!!!

Many thanks,

David

[VocalNeal]

Naam, as you are based in Pattaya can you recommend people to check out my property regarding lightning protection?

The Boswell group I believe are the premier lightning protection company in Thailand. Though big and probably not cheap. I think Erico or something is the main equipmnet supplier you might search for that and see if there is a smaller outfit.

Peter used to work for Bowell but has moved on to other things. I am not sure if he is still dabbling in lightning unless you own a golf course.

Grounding is the key as has been indicated in prevoius posts. I think a triangle of grounding rods all connected but that depends on location and soil conditions. Needs to be something like 10 ohms if memory serves. 1 ohm for telcom sites?

Edited September 16, 2008 by VocalNeal

[Frotting]

Naam, as you are based in Pattaya can you recommend people to check out my property regarding lightning protection? I'm also in Pattaya. Pretty sure that the house electrical system is fine but after the lightning last week I would like an opinion by experienced people on if I need improvements.

David

David, i used one expert to protect my wiring but that is not a 100% percent protection as the strike can come through a phone line (had that case two years ago when a strike fried a modem/router and two motherboards). in addition i used my electrician to set up next to my home a properly grounded 9m high metal pole with a copper rod which drew already two strikes without doing any harm to my home. reason for this was that another strike in 2006 fried three sat-receivers and both LNBs of my sat-dishes which are fixed on a lower pole only 2 meters away from my "lightning rod".

you are welcome to have a drink in my home and take a look at my setup. after that it is up to you to decide whether to use those chaps i used. i can wholeheartedly recommend them.

edited: "with a copper rod" should read topped with a copper rod and grounded with a copper rod both rods connected with a THICK copper wire. and when i talk about a copper rod i mean a copper rod and not usual freaking steel rod which is electroplated with a copper thickness of 1/zillionth of a millimeter that can be licked of by a dog in a minute or two

Guys

Naam is quite right here about using proper materials. Personally I have never understood why the Thais use these grounding rods, they may well LOOK LIKE copper but they ain't copper, and just because something looks like the real thing doesn't mean its intrinsic material properties are the same. In our soil, one of these rods would turn to lump of oxide in a year or two.

I have been trying to source 'correct' materials here in Thailand for some considerable time, but I'm getting there slowly. REAL copper, brass and suchlike IS available here believe it or not. If the mods don't erase it, here's the details of a company who supply non-ferrocious metals:

Porn Prom Metal Public Company Limited

Porn Prom Building,

229 Ratchasima Road, Dusit,

Bangkok 10300, Thailand.

Tel : 0-2628-6100 (15 Lines)

Fax : 66(0) 2280-6289

Web Site : http://www.ppm.co.th

They supply copper bar (the real thing) that is ideal for lightening conductors - I suspect not cheap though. This is what I plan to use - we get some bad storms. Also have aluminium, that should be okay above ground as its conductivity nearly as good as copper and has less of a chance of getting stolen. If you use copper maybe a good idea to paint it or disguise it in some way. Where I live it would be gone in 24 hours.

I'm thinking of running my copper inside a cavity wall, so that it doesn't get stolen, from below ground to the roof and the air spikes.

[moo9]

Naam, as you are based in Pattaya can you recommend people to check out my property regarding lightning protection? I'm also in Pattaya. Pretty sure that the house electrical system is fine but after the lightning last week I would like an opinion by experienced people on if I need improvements.

David

Digging out an old thread now:

Anybody knows a reliable company in Pattaya dealing with proper lightning protection?

Thanks and cheers

[elkangorito]

Being a complete electrics dummy. I researched a bit about lightning protection.

I rather gather that if it is not done 100% correct it can make things a whole lot worse.

Looked a bit complicated to me.

You're exactly correct Lite Beer. It is quite a complicated thing.

The most critical thing is soil impedance (not resistance) followed by the type of earthing array used.

Also, the shape of the conductors (underground & above ground) is also important.

There is, however, a chance that one can "strike it lucky" when doing one's own lightning protection but it's a very slim chance.

Edited August 18, 2009 by elkangorito

[tjo o tjim]

Has anybody tried streamer terminals for residential? We put them on Suvarnabhumi, but truth be told that was as much an architectural solution as engineering decision. Now we seem to be seeing more people going with catenary protection systems for anything critical to maintain separation.

[haveaniceday]

I know this is a old thread, however it is more relevant to bring it up again as there is great stuff in it.

But even though some think that Thai Gravity is different from Farlang Gravity & Thai soil is different from Farlang soil, and simply, Planet Thailand is Independent of Planet Earth ........ I personally disagree & believe that Thai electricity can kill you and your stuff the same as Farlang electricity !!!!

After reading the threads on this subject, I really don't know where to start. Building a single story house, will have a steel frame roof on concrete pillars.

Is there anything I should get the welders to do this week while building the roof?

The budget is tight, very tight, but also don't want to be stupid about a false economy of a few baht now can offer some protection.

Thanks,

Couple of other useful links below for other folks also thinking they are also at risk.

http://www.thaivisa....ection-devices/

http://www.thaivisa....ing-protection/

Edited November 21, 2011 by haveaniceday

[Kwasaki]

After reading the threads on this subject, I really don't know where to start. Building a single story house, will have a steel frame roof on concrete pillars.

Is there anything I should get the welders to do this week while building the roof?

The budget is tight, very tight, but also don't want to be stupid about a false economy of a few baht now can offer some protection.

Thanks,

Couple of other useful links below for other folks also thinking they are also at risk.

http://www.thaivisa....ection-devices/

http://www.thaivisa....ing-protection/

Firstly make sure your welders are not blowing holes in your steelwork, usually just wearing sunglasses and not using proper equipment is a give away.

When it comes to lightning be dam careful, there is a lot of contradictory information out there and on here, sadly I would no-more trust in a Thai electrical company anymore than the local farm builder outfit.

With lightning you do an assessment of of your surroundings, trees near enough if hit by lightning would land on your house, are you near or next to taller buildings, is your building very high etc.

Anyway good stuff here :- http://www.lightningsafety.com/nlsi_lhm.html

[Crossy]

Tight budget single floor home (bungalow) = roof steel welded to column re-bar with no concrete ring beam. I suspect your roof steel will be pretty well grounded already. Google 'Ufer ground' for the reasoning / mechanism.

I doubt you'll be in the market for an actual strike and should concentrate on protecting your electrical system from lightning induced surges.

[haveaniceday]

When homes are built on concrete slabs, it is common practice to bring one end of the rebar up out of the concrete at a convenient location to make an easy connection point for the grounding electrode. http://en.wikipedia.org/wiki/Ufer_ground

Few buildings, even those under construction today are built to take advantage of the Ufer ground. http://www.psihq.com/iread/ufergrnd.htm

Thanks Crossy, wish I knew this last week. Yes, steel roof frame welded directly to rebar in the pillars. The slab is 5.2m above the original ground level, next closest structure is about 110m away, and will not be any tall trees near the house. I am not sure how many strikes get the ground, but there is no shortage of strikes around here. I presume you are suggesting there is no need for a spike on the roof?

[electau]

Lightning protection.

Most buildings do not require lightning protection as such.

Most damage is caused by surge voltages entering the system through the distribution system.

1. Make sure you have a compliant earthing system and main earth/ electrode.

2. Equipotentially bond all structural steel work.

3. Install SPDs on the main switch board on the line side of any RCD protection. Protect with a 32A MCB. Connect with 6.0 sqmm earthing conductor to the earth bar.

TT systems are more risk than a compliant MEN system and require SPDs on the Line and Neutral conductors.

If you do have lightning rod(s) the earth electrode of the lightning protection system should be equipotentially bonded to the main electrical installation earth.

　

　

　

　

　

[Kwasaki]

Tight budget single floor home (bungalow) = roof steel welded to column re-bar with no concrete ring beam. I suspect your roof steel will be pretty well grounded already. Google 'Ufer ground' for the reasoning / mechanism.

I doubt you'll be in the market for an actual strike and should concentrate on protecting your electrical system from lightning induced surges.

Would this be OK as a main earth or would additonal earth wire runs be required.

Earthing.bmp

Edited November 22, 2011 by Kwasaki

[haveaniceday]

After reading more, and a couple of very helpful PM's, this thread is alive again for all to benefit.

The house I believe in my uneducated opinion is prone to a lightning strike, it is in the middle of cleared 6 rai, with no trees and is raised several meters. I have seen a huge amount of lightning activity around the area and many power failures.

I am not sure it's name, pic to come, on the 4 inbound cables from the street, we have some little arrester devices that run to a earth stake, this is about 10m from the street. Told that if the street gets a strike, these will sacrifice and the flow will go to ground, maybe something was lost in translation.

Next, how to best ground the house, I am not sure, any suggestions would be good, I plan on many surge arresting devices scatted around on computers etc, but this is about lightning strikes, (note, house is a bungalow on 9m deep concrete pillers, then joined with rebar and concrete to a 'grid' of concrete & rebar supports with the slab on that and pillers of rebar and concrete with a steel roof welded to the rebar in the pillars.) Just a very normal construction, but that may help for advice.

We asked the builder to arrange lightning spikes, what he did was put 20cm of rebar poking up at each end of the house, after all the trimming, these will poke out about 10cm I guess. Just enough to be annoying, leak and do nothing it was intended for, these are welded to the steel frame of the house directly.

I know very little about this, but I think this should be questioned. ( Very Politically correct eh? )

I believe I need a 5 pointed prong thingo at each end of the house to provide a cone of protection, what are they made out of, in Thailand are they the same as earth rods, should be copper but are steel with a copper coating, is this not important?

The big question is, as the roof is being built this week, how to get it mounted properly, the builder is clearly clueless on this, the metal roof would be the support I presume, and would be best to have it insulated form the steel structar of the house, eg, insulated spike, cable to deep earth rods.

"Bond your roof metalwork to the lightning rod, but whether you also bond to your power ground is open to debate. In Oz they do in Europe they don't.." What does this mean exactly?

Anyone have any suggestions on how to get it mounted on the top of the roof, would all the energy from a direct strike jump anyway?. Can the ugly cable be in yellow pipe and hidden in the render of the wall? This is my main query right now.

Thanks, PS, never underestimate the stress of building a house in LOS, Land Of Stress

[electau]

"Bond your roof metalwork to the lightning rod, but whether you also bond to your power ground is open to debate. In Oz they do in Europe they don't.." What does this mean exactly?

Equipotential bonding, all conductive metal which may enter the ground are all at the same potential. (AS 3000). There is a separate AS1768 standard for lightning protection systems.

Edited November 29, 2011 by electau

[Kwasaki]

http://www.lightning...m/nlsi_lhm.html

http://lightning-systems.com/

Not too sure didn't get an answer on it but if your basic set up is something like this and have a single storey building it may not be necssary to do more.

Earthing.bmp

Edited November 29, 2011 by Kwasaki

[haveaniceday]

Referencing post #20 / 21 Ufer Ground

Some diagrams refer to a protruding bit of rebar that is connect to a earth rod in the ground.

Other writings refer to the concrete being a 'conductor it self and doesn't require a earthing (ground rod) into the ground.

Question : Would it be worth to connect a thick copper wire from some of the steel roof structure to a separate ground rod away from the consumer units ground?

Side note, I think, (and only think) UK, Australia refer to earthing and USA refer to grounding, correct me if I am wrong.

Wiki says:

Ufer discovered that the naturally high pH level in concrete meant that it had a ready supply of ions, and would provide a better electrical ground than almost any type of soil. Ufer also found that the soil around the concrete became "doped", and its subsequent rise in pH caused the overall impedance of the soil itself to be reduced.^[3] The concrete enclosure also increases the surface area of the connection between the grounding conductor and the surrounding soil, which also helps to reduce the overall impedance of the connection.

Ufer's original grounding scheme used copper encased in concrete. However, the high pH of concrete often causes the copper to chip and flake. For this reason, steel is often used instead of copper.

When homes are built on concrete slabs, it is common practice to bring one end of the rebar up out of the concrete at a convenient location to make an easy connection point for the grounding electrode.^[4]

Ufer grounds, when present, are preferred over the use of grounding rods. In some areas (like Des Moines, Iowa) Ufer grounds are required for all residential and commercial buildings.^[5] The conductivity of the soil usually determines if Ufer grounds are required in any particular area.

An Ufer ground of specified minimum dimensions is recognized by the U.S. National Electrical Code as a grounding electrode.^[6] The grounding conductors must have sufficient cover by the concrete to prevent damage when dissipating high-current lightning strikes.^[7]

A disadvantage of Ufer grounds is that the moisture in the concrete can flash into steam during a lightning strike or similar high energy fault condition. This can crack the surrounding concrete and damage the building foundation.^[8]

[Kwasaki]

IF you have accessed your area and you are that worried about lightning run a separate system.

Lightning rod fixed to the highest point on the house, cable run along roof and down the side of house to a grounding rod a suitable distance from the house foundations.

What your ground and underground is like has some relevance maybe you will need extra surge protection, there's such a lot of info on the subject.

[haveaniceday]

Why does the cable have to go over the roof?

Why can't the cable go through the roof and down a wall while mounting it on ceramic insulated supports?

Can the energy easily "jump" to the steel rafters?

I also presume there is a high chance of it pouring down with heavy rain if a direct strike was to happen, will the energy run along the wet roof and maybe energize the steel roof?

[Kwasaki]

1. Why does the cable have to go over the roof?

2. Why can't the cable go through the roof and down a wall while mounting it on ceramic insulated supports?

3. Can the energy easily "jump" to the steel rafters?

4. I also presume there is a high chance of it pouring down with heavy rain if a direct strike was to happen, will the energy run along the wet roof and maybe energize the steel roof?

1.The best way / 2. don't want high voltage inside house / 3. I would say maybe it could. / 4. Maybe !!! http://en.wikipedia.org/wiki/Lightning_rod

With greatest of respect I think you are worrying to much, if you want to protect your building from lightning you can.

There is so much info on lightning products it becomes a minefield.

When we fitted lightning cables to buildings the cable was always outside, along the ridge or down the roof slope usually to run down at the rear of the building and the cable were not that unsightly if neatly fitted, what is required is the voltage from a strike to travel the straightest direct route to ground out.

Never had a call back ever but England not the most dangerous place for lightning strikes I guess.