Lightning And Your Electrical Appliances:

[libya 115]

What precautions do you take with your electrical appliances during a violent lightning storm?

Do you disconnect and unplug all appliances?

Is this practical...ie..the fridge? What about the P.C. will a UPS protect it?

Phone lines....disconnect?

What about T.V. unplug cable feed and disconnect from mains power?

I used to turn off the T.V. during a lightning storm, but surely that makes no difference. Maybe I should plug the cable feed into ground/earth.

Does lightning cause a mains power surge (often?) that would damage everything?

And how about a satellite dish? Risky?

Any lightning experiences to share?

[bkk_mike]

Lightning can cause surges, but it would have to hit between the transformer on the pole, and your house, in order to have a chance of really frying things. (i.e. the smell of burning coming from things.)

Having said that, I tend to have microelectronics (computers, router), on a UPS, or at least a power strip with a surge protector. Simply because I've had routers broken by spikes in the UK, and the power there is a lot steadier than it is here. (A UPS is better for desktop PCs because it also gives you a chance to shut down cleanly if there's a power cut, which is not uncommon during rainy season).

I don't bother for regular things like TVs and Fridges, although I do have one TV and my satellite receiver on a UPS, but that's just because I was having picture issues with the TV when the voltage wasn't the 220v it should have been. (Don't know if the problem was with the TV, or with the S-Video out on the satellite - but the UPS fixed it).

Edited September 22, 2006 by bkk_mike

[tjo o tjim]

The best advice is to get a whole-house surge suppressor if you have a lot of lightning in your area. While a direct strike on the power lines isn't as unlikely as a lower-grade impulse, both can cause damage. The surge suppressor would also provide additional protection for the UPS in the hopes that it would not sacrifice itself.

Most things like refrigerators aren't likely to have a big problem with a minor surges; it is just the electronics.

If you don't go for a surge suppressor, try to unplug cords rather than just switching them off (from an outlet strip). Most of the outlet strips only switch the hot wire, so you can still get a surge from neutral to earth.

[astral]

Don't forget the phone wire to the modem.

[nikster]

The best advice is to get a whole-house surge suppressor if you have a lot of lightning in your area. While a direct strike on the power lines isn't as unlikely as a lower-grade impulse, both can cause damage. The surge suppressor would also provide additional protection for the UPS in the hopes that it would not sacrifice itself.

Most things like refrigerators aren't likely to have a big problem with a minor surges; it is just the electronics.

If you don't go for a surge suppressor, try to unplug cords rather than just switching them off (from an outlet strip). Most of the outlet strips only switch the hot wire, so you can still get a surge from neutral to earth.

How much is such a whole house surge supressor and how big is it? I don't have a lot of lightning but the power lines go down all the time (a few times per day).

The problem with that is that when it comes back on, there's a surge going through the cables, sometimes triggering my fridge's surge protector.

The surge can destroy electronics - it has taken out a few air-cons in town; it also increases everyone's power bill. We pay for the privilege of getting our electronics fried every now and then...

[jcgodber]

Every night I unplug my computer and TV I also disconnect the telephone line to the modem. I have now lost 4 modems since I have been here in Thailand (4 years). Even during the day now when I am not using the modem I disconnect it. As it is right now, I am using the only modem that is for sale here in Sa Kaeo . I paid 320 baht for it and you get what you pay for. I now need to buy another better modem.

During a lightning storm we unplug every thing that we can. I too would be very much interested in information about an all house lightning suppressor. I do have a lightning rod mounted on my roof and it runs to ground.

[scotsman]

I think they mean a safety cut that cuts the power when there is a overload or underload or short circuit like this one cost about 3000 to 5000 baht.

[Brew]

have a look at the english pages of http://dehn.de

everything you need should be around 800 Euro. I do not know the price of their Bangkok based branch) ... expensive, I know. But the last damage at my home has been over 10.000 Bt already,including the UPS the devices had been connected to. So it will make sense.

The "Safety Cut" and a UPS is no lightning protection!

Edited September 24, 2006 by Brew

[drake]

Lightning Protection:

First question is where we have high Voltage by Thunderstorm Lightning.

This is between Phone line and Power line, except see below.

To protect Computer and Modem it’s necessarily to eliminate this high Voltage.

UPS with Phone line protection use ZNR (allow only pass voltage up to about 300 Volt) and 2 Resistors (most 10 Ohm) in the Phone line. The ZNR limit the Voltage between Phone-, power line an Ground. If lightning stroke, the 2 Resistors can blow out and must be replaced, bud PC and Modem will be intact. (I’m replaced already 3 times).

Not all UPS (uninterruptible power supply) support real Protection (Leonics and APC will be OK). Most Notebook PC’s today have W-Lan integrated and with a W-Lan Modem (ADSL, e.g. D-Link G604T) and wireless, the loop between Phone and Power line not exist (recommended). Worst case the modem blow out, bud the modem is much cheaper as Notebook repair.

Except the Lightning strike near (about 5 meter) or direct in house.

15 years ago the Lightning stroke in the water tower near my house. Result:

Shortwave Antenna no more exist, Shortwave Receiver, Modem, SCSI Interfaces, PC, Stereo, TV’s, Phones, Fluorescent Lights destroyed.

Refrigerators and Aircons are still OK. In this case it’s impossible to protect. Even a piece of unconnected wire has high voltage.

[astral]

I think they mean a safety cut that cuts the power when there is a overload or underload or short circuit like this one cost about 3000 to 5000 baht.

The safety cut will save your life if there is a short circuit,

but is not fast enough to deal with lightening.

This is what a lightening strike did to my neighbours electric meter.

[macb]

When they did the wiring for my house I told the electrician I want important power points earthed which he was doing anyway, but then I asked for the consumer unit to be ground as well which he did.

So oven, fridge,computer points,air-con

Is this sufficent does it help?

macb

[elkangorito]

Lightning Protection:

First question is where we have high Voltage by Thunderstorm Lightning.

This is between Phone line and Power line, except see below.

To protect Computer and Modem it’s necessarily to eliminate this high Voltage.

UPS with Phone line protection use ZNR (allow only pass voltage up to about 300 Volt) and 2 Resistors (most 10 Ohm) in the Phone line. The ZNR limit the Voltage between Phone-, power line an Ground. If lightning stroke, the 2 Resistors can blow out and must be replaced, bud PC and Modem will be intact. (I’m replaced already 3 times).

Not all UPS (uninterruptible power supply) support real Protection (Leonics and APC will be OK). Most Notebook PC’s today have W-Lan integrated and with a W-Lan Modem (ADSL, e.g. D-Link G604T) and wireless, the loop between Phone and Power line not exist (recommended). Worst case the modem blow out, bud the modem is much cheaper as Notebook repair.

Except the Lightning strike near (about 5 meter) or direct in house.

15 years ago the Lightning stroke in the water tower near my house. Result:

Shortwave Antenna no more exist, Shortwave Receiver, Modem, SCSI Interfaces, PC, Stereo, TV’s, Phones, Fluorescent Lights destroyed.

Refrigerators and Aircons are still OK. In this case it’s impossible to protect. Even a piece of unconnected wire has high voltage.

When they did the wiring for my house I told the electrician I want important power points earthed which he was doing anyway, but then I asked for the consumer unit to be ground as well which he did.

So oven, fridge,computer points,air-con

Is this sufficent does it help?

macb

May I suggest that everybody go to Domestic Electrical Wiring in this forum, to find out some realities about electricity. The normal earthing of electrical equipment will do almost nothing to protect your equipment. Using small standard electronic protection devices will also fail to offer adequate protection. For safety, never assume that any purchased electrical/electronic device has 'built-in' lightning protection.

Secondly, I suggest a reading of either of these sites http://www.lpi.com.au/pages/protection_sol...four_step3.html

http://www.erico.com/products.asp?folderid=47

as they will you enlighten you upon the complexity & range of APPROPRIATE products available to assist with surviving a lightning strike.

You may also like to check the following site, which contains all of the information that exists in the Domestic Electrical Wiring site but in a condensed & simpler form. The information includes a brief upon Lightning Protection.

http://crossy.servebeer.com/wiring/

Edited October 31, 2006 by elkangorito