Power Surge Caused By Lightning

[gardenubon]

hi, hoping someone can help.

as the summer storms hit our village there was a power surge and in our shop the fridge and chest freezer are now damaged.

as i dont know anything about electrics, i have no idea what we need to stop this happening. also can it do the same to your tv? also are mobiles dangerous with lightning? i know we have an earth for the hot shower, but now im generally worried about all my electrics as they are typical thai style

[garyh]

Safest way is to pull the plugs out during storms, as for your shower heater the earth on it will not stop it getting fried.

[noahvail]

Agreed.

You can also put a half-way decent surge protector on each outlet. A lightning strike will fry the surge protector and then the appliance, but at least you can show the insurance company that you took all due precautions.

[Naam]

Agreed.

You can also put a half-way decent surge protector on each outlet. A lightning strike will fry the surge protector and then the appliance, but at least you can show the insurance company that you took all due precautions.

the surge protectors available in the markets are nothing but toys and will protect against average power surges originating by the electricity provider. there are no surge protectors which fully protect against a direct lightning strike. i've put a whole-house system in that cost >15,000 Baht (after 2 SAT-receivers, 1 TV, 1 PC and 2 routers were fried) but i am well aware i am only protected up to a certain extent.

[sbk]

Safest way is to pull the plugs out during storms, as for your shower heater the earth on it will not stop it getting fried.

Our phone line got a direct hit and the surge fried our router, computer, monitor, printer plugged into the computer and fax machine. we didn't have the phone line plugged into the UPS because our signal was too weak to do so. Lightning bolt came out of the blue tho, so no chance to unplug. But now, when I see a big storm coming, I unplug my expensive stuff.

Oh, and btw, my neighbor also got a direct hit, hit his place first and travelled down the phone line to my place. The lightning bolt drilled a hole in the tile and cement floor, shattered the rafter in the room, scorched the mattress, blew the hot water heater and aircon off the wall, fried as well, fried his computer, router, monitor, printer, mobile phone that was plugged in charging literally blew up into little pieces and he had to replace all his light bulbs.

[stgrhe]

I bought my surge arresters from Dehn, one for the power line that protect us up to 40kA, one for the telephone line and one for the satellite antenna.

http://www.dehn.de/en/products/red.shtml

They have real stuff, but as Naam says, the arresters do only provide protection to a certain limit.

[slapout]

I had lightening hit my office room in the house. It scorched everything that was plugged into a socket via surge protectors or not. It required replacement of computer,monitor, copy machine, fax machine all lights even got the telephones. No other part of the house was affected and no breakers were thrown. Did have a nice hole in the roof.

[bankruatsteve]

Agreed.

You can also put a half-way decent surge protector on each outlet. A lightning strike will fry the surge protector and then the appliance, but at least you can show the insurance company that you took all due precautions.

the surge protectors available in the markets are nothing but toys and will protect against average power surges originating by the electricity provider. there are no surge protectors which fully protect against a direct lightning strike. i've put a whole-house system in that cost >15,000 Baht (after 2 SAT-receivers, 1 TV, 1 PC and 2 routers were fried) but i am well aware i am only protected up to a certain extent.

Just to add... I have a "surge suppressor" (bought at one of the dept stores) that did NOT clamp when we had over 350v from the electric company for several hours. When I checked the unit, there was no information stating the clamp voltage. So, I don't know what it is here in LOS. In the states it's usually about 300v. Anyway... that took out a 3 month old refrigerator that we eventually got repaired for no cost (outside of hauling expenses and an annoying 2 weeks to get the parts). I'm pretty sure the only thing replaced was the circuit board that probably just needed some MOV's replaced. OP: if your stuff has similar protection you may just need some relatively cheap electric parts replaced. (?)

[garyh]

Safest way is to have a battery bank charged by the mains and run everything off the batteries through an inverter. If there is a storm threat you can still disconnect the charger, another benefit is no blackouts.

[IMA_FARANG]

Not much you can do when Mother Nature decides to zap you.

Even disconecting or unpluging may not save you if the equipment is grounded or earthed somehow.

I once saw a case where lightning struck a large rock outside an equipment shelter we had.

It was clear that the lightning bolt had hit the rock because of the burn mark on the rock.

About 5 feet from the rock our grounding/earthing rod was buried for grounding the equipment shelter.

We had three communications recievers in that shelter. Two of them were destroyed by the lightning hit.

All the damage came from the electric current that entered into the equipment on the ground/earth path.

We believed that when that large rock was hit by the lighting bolt, the nearby area must have been charged up for a brief period. Since our grounding rod was within 5 feet of that rock, the charge travelled through the ground system, and blew out our communications recievers in the shelter.

A freak accident, but it just shows the power of a nearby lightning strike.

Edited May 1, 2010 by IMA_FARANG

[elkangorito]

Are you saying that your equipment was not 'plugged in' & that somehow, the 'earth' circuit destroyed 'unplugged' equipment, due to the lightning strike?

[IMA_FARANG]

Are you saying that your equipment was not 'plugged in' & that somehow, the 'earth' circuit destroyed 'unplugged' equipment, due to the lightning strike?

No, I didn't intend to imply that. The equipment was plugged in. One unit was in operation, one on hot-standby, and one turned off. The cabinet the units were in were also earthed with a large ground wire to the grounding rod outside by that rock. The rock had a large black burn where the lightning had hit. The ground wire cable also showed evidence of being heated by the current it carried for tha short period after the bolt hit the rock.

All 3 units were plugged in. I can't recall which were the two that were destroyed. We managed to canabalise enough parts from the two destroyed units to put together one good unit. It took us 3 or 4 days to get that one unit working as the hot-standby backup unit.

Anyhow, all I meant to imply is that a lightning strike near enough to the earth/ground rod can bring in enough of a surge from the ground system...even if it is only for a few milliseconds...to cause serious damage to equipment on that the earth connection.

[longball53098]

I'm not an engineer or scientist but the limited reading I have done about lightning strikes and EMF seem to suggest if a direct hit to a building occurs that the chances of the current destroying electronic/electrical devices even if not plugged in is a pretty good chance. Most of us have heard that when a nuclear bomb is exploded the EMF will fry anything in the area powered up or not so I would think the same would be true for devices in a building hit by lightning

[gardenubon]

ok, never realised this was so common. can i just switch off the cut off? or do i have to unplug aswell? can i make a earth conductor on my water tower?

[garyh]

ok, never realised this was so common. can i just switch off the cut off? or do i have to unplug aswell? can i make a earth conductor on my water tower?

If you want to be lazy and just turn the switch off you may as well not bother at all just leave it on.

[Naam]

Agreed.

You can also put a half-way decent surge protector on each outlet. A lightning strike will fry the surge protector and then the appliance, but at least you can show the insurance company that you took all due precautions.

the surge protectors available in the markets are nothing but toys and will protect against average power surges originating by the electricity provider. there are no surge protectors which fully protect against a direct lightning strike. i've put a whole-house system in that cost >15,000 Baht (after 2 SAT-receivers, 1 TV, 1 PC and 2 routers were fried) but i am well aware i am only protected up to a certain extent.

Just to add... I have a "surge suppressor" (bought at one of the dept stores) that did NOT clamp when we had over 350v from the electric company for several hours. When I checked the unit, there was no information stating the clamp voltage. So, I don't know what it is here in LOS. In the states it's usually about 300v. Anyway... that took out a 3 month old refrigerator that we eventually got repaired for no cost (outside of hauling expenses and an annoying 2 weeks to get the parts). I'm pretty sure the only thing replaced was the circuit board that probably just needed some MOV's replaced. OP: if your stuff has similar protection you may just need some relatively cheap electric parts replaced. (?)

a power surge originating from the electric company is a piece of cake compared to a lightning strike into a nearby power or phone line.

[Honolulu]

Some of you have talked about " surge protectors ". Are these the same as a "fused" power strip? I have all my appliances plugged into "fused" power strips, and no problems yet.

[Naam]

Some of you have talked about " surge protectors ". Are these the same as a "fused" power strip? I have all my appliances plugged into "fused" power strips, and no problems yet.

because you had not lightning strike... yet

[bankruatsteve]

Some of you have talked about " surge protectors ". Are these the same as a "fused" power strip? I have all my appliances plugged into "fused" power strips, and no problems yet.

Fused power strips simply protect against overloads. "Surge suppressors" usually employ metal-oxide-varistors (MOV) that will clamp within nanoseconds of a power surge - and should protect against even lighting strikes. But as you can see from posts, direct hits are a completely different animal.

[gardenubon]

ok, never realised this was so common. can i just switch off the cut off? or do i have to unplug aswell? can i make a earth conductor on my water tower?

If you want to be lazy and just turn the switch off you may as well not bother at all just leave it on.

what? im not lazy, was just asking a few questions. do you think someone would be too lazy to pull out a few plugs? <deleted>?

[bdenner]

As it turns out we were hit last night, the tin roof of 'Mares' bungalo which adjoins our house. I was just completing my shower when there was a bang and I felt a slight jolt. The ELCB on the instant hot water system tripped as well as the 2 RCD's we have protecting the homes. Our home is FULLY earthed so with that and the other protection devices we were spared any damage. Not to say that if the strike had hit the TV antenna or Satalite dishes that those appliances would have survived, dead for sure.

[david96]

In Australia we have severe lightning storms any one living in the tropics and the NT would know of its effects especially in the remote areas.

But we do have good earthing requirements.

In areas of high risk surge protectors may be installed at the main switch board, and on sub boards, protected by MCBs. Along with surge protected power boards at the equipment end.

MEN system mandatory. Most strikes are taken by the HV arresters at the transformer Earthing of the neutral also provides protection if the strike hits the LV.

The phone line should be protected by gas filed arresters where it enters the building.

One can only minimise the risk of damage. Unplug equipment that may be affected during an electrical storm.

[loong]

Had a lightening strike a few weeks back.

I guess that it hit my antenna for my CAT-CDMA modem

I wasn't using the computer at the time, but the modem and Computer were totally fried. Monitor unscathed. The trip on the mains shut down the power and no other electrical devices were damaged.

I now know to disconnect the antenna lead from the modem when not using it.

Lightening doesn't strike twice in the same place? An old wives tale I think.

The antenna is the highest point in the immediate vicinity, so I'm obviously concerned that lightening will strike twice.

Would a lightening rod placed close to the antenna attract the strike away from it and safely to earth?

[garyh]

ok, never realised this was so common. can i just switch off the cut off? or do i have to unplug aswell? can i make a earth conductor on my water tower?

If you want to be lazy and just turn the switch off you may as well not bother at all just leave it on.

what? im not lazy, was just asking a few questions. do you think someone would be too lazy to pull out a few plugs? <deleted>?

As myself and other said you have to pull the plug but you are asking can you not bother and take the easy way out by just turning off the switch.

[SiangDeeMahk]

Can I just add a little point about lightning strikes, that it appears no one is addressing?

A bolt of "cloud-to-ground" lightning emanates from the bottom of a cumulus (or cumulonimbus) cloud* which bottom is often at a height of 2,400 meters (8,000 ft) from the ground. Sometimes, up to a height of 6,000m (20,000 ft). It then travels 2,400m (or more, if traveling somewhat diagonally) through nothing but air (a very poor conductor of electricity) before making contact with the ground.. or something associated with your house.

This through-the-thin-air spark, which has just traversed an insulator 2,400m wide (the atmosphere) is NOT going to have any trouble getting past ANYTHING that you try to put in it's way, in the last 10m of it's journey. PERIOD. Nothing.. I repeat, NOTHING "stops" lightning. The only thing that you can do, is try entice it to choose an easier path to the ground (via a very robust lightning rod with grounding scheme), than a path that will bring it through your house or through the bits of metal (ie: wires) that service it.

And yes, even a really good grounding solution may not be able to eliminate the effects of the EM (electro-magnetic) pulse that a lightning strike creates, on your delicate electronic devices, even if they're unplugged. But unplugging them COMPLETELY (not just switching off a powerstrip, but physically moving them away from phone, cable/sat and electrical lines in your house) certainly makes it much more likely that they'll survive. EM energy does travel through thin air, but it travels much better (as all energy does) through/along metal.

Actually, that phenomenon can be used to your advantage: Those of you with incredibly important electronic devices, who are often exposed to lightning, could consider something called a "faraday cage".

http://en.wikipedia.org/wiki/Faraday_cage

To be thoroughly technical, it may be useful to compare the conductivity of Air, relative to..let's say, Aluminum (power lines).

The conductivity of Aluminum: 37.8 × 10⁶ (that's simiens per meter)

The conductivity of Air: 0.8 × 10^-14

(please see http://en.wikipedia.org/wiki/Electrical_conductivity)

This simply shows that air has a much higher resistance to conducting electricity (or lightning bolts), than virtually anything else on the planet. So, a spark is not easily made to jump through thin air, and if it does have enough energy (in this case, 1 billion joules worth) to make that incredible leap up to 6,000m through thin air, YOU (and a tiny 2cm silicon "MOV" component in a 600Bt "surge protector") AIN'T STOPPIN IT from getting into your devices.

Surge protectors are only designed to protect against switching spikes (when a strong inductive load, like an electric motor turns on or off), and slight overvoltage conditions from the power company. Their little silicon bodies were never meant to Muay Thai with Mother Nature.

For the record, in spite of the untruths believed by many people (probably a result of them not being able to technologically differentiate the fact that storm warnings about using WIRED phones don't also apply to mobile phones), mobile phones offer no increased potential for attracting or conducting lightning hits. Unless they're plugged into a charger, they're perfectly safe to use (as safe as any other non-grounded object with a tiny bit of metal in it, like a flashlight, or an expensive pen) during a thunderstorm. Or unless you are standing out in the middle of a vast, completely flat field, with your mobile (and it's nearly negligible metal content) held way, way up over your head.. in the middle of a violent lightning storm. In which case: A) it's your body's mass, and it's connection to the earth that's attracting the strike, and you're an freakin idiot, and Darwin posthumously thanks you in advance for volunteering to cleanse the genepool of your obviously damaged DNA.

Final fact: If you DO find yourself out in the middle of a field during a storm, and feel the air near you energize, smell ozone (similar to the smell that comes from an older "photo-stat" copy machine, or more likely; feel prickles on your skin, or your hair standing up, an electrical charge is building up near you, and a strike is likely. Best thing to do? Don't lie down! The charge traveling through the ground from a nearby strike can electrocute you if you're laying flat on the ground, especially if it's wet. Instead, quickly bend down with your hands on your calves/ankles, putting your butt up into the air as the highest point on your body. It turns out, that if you ARE going to be directly hit, the best thing is to offer the lightning "a path through you" where it doesn't have to go burning through your vital organs (including your brain), and in this position, the likely path will be: your butt; your legs; your feet, and then into the ground... missing all those vital organs.

Ya can't make this stuff up, folks.

*Technically, a negatively charged "stepped leader" starts out from the cloud, then meets a positive charge that develops up from the ground, and the main bolt then traverses this pre-established path, but the direction of flow is not important here; only the path and the threshold of energy required for the bolt to be able to "arc" over a given insulating distance)

{reason for edit: Typo, and added hyperlink for reference}

Edited May 6, 2010 by SiangDeeMahk

[Donnyboy]

Final fact: If you DO find yourself out in the middle of a field during a storm, and feel the air near you energize, smell ozone (similar to the smell that comes from an older "photo-stat" copy machine, or more likely; feel prickles on your skin, or your hair standing up, an electrical charge is building up near you, and a strike is likely. Best thing to do? Don't lie down! The charge traveling through the ground from a nearby strike can electrocute you if you're laying flat on the ground, especially if it's wet. Instead, quickly bend down with your hands on your calves/ankles, putting your butt up into the air as the highest point on your body. It turns out, that if you ARE going to be directly hit, the best thing is to offer the lightning "a path through you" where it doesn't have to go burning through your vital organs (including your brain), and in this position, the likely path will be: your butt; your legs; your feet, and then into the ground... missing all those vital organs.

Ya can't make this stuff up, folks.

alternatively, you could bend over put your head between your knees and kiss yr ass goodbye

[SiangDeeMahk]

Final fact: If you DO find yourself out in the middle of a field during a storm, and feel the air near you energize, smell ozone (similar to the smell that comes from an older "photo-stat" copy machine, or more likely; feel prickles on your skin, or your hair standing up, an electrical charge is building up near you, and a strike is likely. Best thing to do? Don't lie down! The charge traveling through the ground from a nearby strike can electrocute you if you're laying flat on the ground, especially if it's wet. Instead, quickly bend down with your hands on your calves/ankles, putting your butt up into the air as the highest point on your body. It turns out, that if you ARE going to be directly hit, the best thing is to offer the lightning "a path through you" where it doesn't have to go burning through your vital organs (including your brain), and in this position, the likely path will be: your butt; your legs; your feet, and then into the ground... missing all those vital organs.

Ya can't make this stuff up, folks.

alternatively, you could bend over put your head between your knees and kiss yr ass goodbye

Bravo! Let's all just hope and pray that you're not the only one that caught onto my "drift" there.

(being that the point of my post was that basically, NOTHING stops lightning)

But in all truth: Ass in the air, baby! It's your best bet at beating the bolt!