Hit by lightning

[réjean]

The following happened down ( or is it up?) the road, as a matter of fact only 5 houses away from ours;http://www.cbc.ca/ne...ttage-1.2734013

 

At least 3 of my neighbours and us have lost a router and a computer. Fortunately ( if there is such a thing) only my wife's old computer and our router were zapped. I had 2 machines upstairs ( mine running ) that didn't get affected. The other I had installed Win XP and Win 7 on and migrated all her data onto so she lost only a couple of weeks of emails ( Fortunately again she uses Gmail besides our ISP mail ).

 

I tried her hard drives into my computer but the BIOS doesn't see them nor my OSes so I guess the data is lost. We were at the local farmer's market when it happened. The forecast was for 60% chances of thunder showers ( 15 mm ) in the late afternoon so I hadn't turned off the computer before we left. My wife add to go back home because she had forgotten a basket of zucchinis but didn't bothered turned the computers off. So we have only ourselves to blame. Believe it or not but we got 78 mm of rain in 3 hours and some villages nearby got barely 10.

It happened Saturday morning and I called our ISP in the afternoon. They only thing they could give us at the time was the normal 5 free hours of Dial-Up because it was on a week-end and to put us on a list for a new router delivered by mail within 2-3 business days. I called them back yesterday, Monday, and got extended credit for dial-up but the connection (45 Kbps) was atrocious taking up to 10 min to load up a web page if we didn't get disconnected. Anyway! We got a new router this afternoon and I am back online again.

I doubt there is a way to recover the lost data is there? I don't care too much about her machine, a Penthium III 1 Ghz with less than 700 MB of RAM and 2 old 40 GB HD at what was it 5200 or 5400 RPM.

Oh! Last thing. Her machine and mine are behind a UPS which is behind a power bar and she still got zapped so next time there is a thunderstorm I will not only turn off our machines but unplug them from the wall because we cannot afford losing another one.

Edited August 12, 2014 by réjean

[V.T. Eric Layton]

Rejean,

 

I may be uniquely qualified to respond to you regarding lightning and lightning damaged electronics. I live in Florida, as you know. Tampa has been called the "lightning capitol of the world" many times in the media over the years. For 20+ years, I was an electronic technician. Part of my job at one company that I worked for involved confirming/denying claims for some of the big insurance companies (AllState, State Farm, Nationwide, etc.) when they would send equipment to our facility after picking it up from their customers' homes.

 

Lightning is an amazingly powerful force of nature. While surge detectors and such are helpful in protecting your electronics and other household items from surge damage caused by line faults or by lightning in the area, they are NOT able to provide 100% protection. Lightning is also a strange critter. It can hit right in between you and your neighbor's house and totally destroy everything connected to your electrical system while leaving your neighbor unaffected.

 

If those hard drives had their electronics toasted by the surge they were submitted to, then you'll probably never get them to power up and work again. You can retrieve data from an electrically/mechanically malfunctioning drive, but it is a costly procedure. There are companies around that will disassemble your drive and remove the data platters. They then install those platters into jigs that can access that data. A transfer is made to external media... DVD, CD, etc. and these are provided to you. The cost starts at about $300. I tell my customer's that ask me about this that they must decide if the data on those damaged drives is worth investing at least this amount to recover. Most say no, that it isn't. It's a personal choice, of course.

 

I don't mean to make light of your storm there, but this is an every afternoon thing here in Tampa. We often get 78mm (3"+) rain in one shower on any random summer afternoon here in Tampa. There may be thousands of lightning strikes per minute during these often violent thunderstorms. I grew up with this. Oddly enough, we Florida folks don't even think about this stuff. It's just all part of living in the Sunshine State (regular and liquid sunshine).

 

Anyway, sorry about your loss of data. BACKUP! BACKUP! BACKUP! That's really the ONLY way to protect personal data. You can never trust just one electronic/mechanical device (hard drive, solid state drive, etc.) to store your important data. You need multiple redundancies and backups on non volatile media (CDs, DVDs, etc.). It's the only way.

 

~Eric

[réjean]

Thanks Eric! That's what I think too!

[goretsky]

Hello,

 

Just to add to Eric's comments, I used to live in Colorado not too far from Pikes Peak, where Nicola Telsa set up a lab to study lightning. A few observations:

 

I once saw a 56K PCI Modem card that was apparently plugged into a phone line that had taken a nearby lightning strike. The PCI slot it was in was dead (no surprise), but what surpised me was that there was a hole the size of a BB with in the HSP chip. If you looked on it from straight down with a flashlight, you could see the burnt silicon at the bottom.

 

Devices like surge protectors degrade over time. I had a discussion about it here on it another forum many years ago. In a nutshell, though, the technologies used in surge supression are not unlike brake pads in your car. Repeated use causes them to wear out.

 

Likewise, electronic appliances are typically designed with at least some small ability to handle surges, dirty power, etc., in order to pass their UL (TUV, CE, etc.) certification, but keep in mind that usually does not mean a nearby lightning strike, let along a direct one. My last employer made telephony equipment (PBXes, handsets, PoE switches, UPSes, etc.) and their equipment was certified for use by telcos, which requires some different standards for handling lightning. They still had to be plugged into surge supression systems, though, and the certification meant that when the equipment did suffer a lightning strike, it would not cause a fire. That's it. No survivability at all, just that it wouldn't start a fire.

 

I am not sure if whole house surge supression systems are common anymore, but the power company in Colorado used to offer them as an add-on for a few addditional dollars a month. From what I recall, it was a lightning gas arrestor that plugged in between the incoming power line and the power meter on the outside of the house. Eventually, though, they stopped offering the service. It still might be a good idea to look into this or a similar protection if you are in an area where lightning is a regular occurance.

 

It is still a good idea to unplug expensive electronics, though (home entertainment system, computers, etc.). Also, it's important to remember that phone lines, cable TV, antennas are also targets for lightning, not just AC power, so protect those accordingly as well.

 

Regards,

 

Aryeh Goretsky

[réjean]

Thanks Aryeh!

[Guest LilBambi]

Yes, lightning is a strange bird. My Jim has harped on people unplugging their electronics during electrical storms for years.

 

Yes, he does shutdown and unplugin any electronics he can't afford to lose. That would be most everything by the way. TVs, stereos, DVD players, etc., and of course any other computerized equipment including his computers.

 

We do more than that. The A/C/heatpump unit uses both sides of the line and Jim turns it off and purposely flips the dual breaker to protect the unit.

 

The only thing we don't unplug is the refrigerator but we cringe the whole time. Refrigeration equipment doesn't recover well when the power spontaneous goes off and then 'surges' when it comes back on. Or does that repeatedly which can happen in a severe thunderstorm (up to three times anyway around here). That's why the A/C is turned off and the breaker tripped intentionally on the A/C circuit.

 

I learned from Jim in this regard. I turn off and unplug my computers if I leave the house and go more than 5 minutes away if ANY percentage over 10% of Thunderstorms are predicted. The only computer I leave running is my Raspberry Pi. If I need a computer, there is my phone and my unplugged but charged laptop.

 

So sorry for you losses, réjean!

Edited August 13, 2014 by LilBambi
can was supposed to be can't in 2nd paragraph

[raymac46]

Wow, that was really scary réjean, Sorry your equipment got damaged.

I'm not really living in tornado alley here in Almonte, but I do try to switch things off if thunder is in the forecast. I have surge protectors on my computers but I don't really think they would help in a lightning strike.

The only thing I've ever lost to lightning is one of those old fashioned dial up 56K modems, and that happened even with the power switched off. The rest of the computer was not affected.

[V.T. Eric Layton]

@ Aryeh... Yup. TECO (Tampa Electric Company) offers their "ZapCap" device for total home protection. Of course, it only works to a certain extent. Nothing can protect against a direct hit. I've seen lighting blow a corner off of a concrete block house here in Tampa when it directly hit the home's electrical drop's weather head on the roof.

 

@ Fran... JL is right. Back in the day, when I had my bench set up with all my test equipment and my radios (CB, 10M, 2M, SW), power to the bench was provided by one heavy-duty 10-3 cable and plug that was plugged into a dedicated outlet (30A breaker). Whenever this stuff wasn't in use, it was completely disconnected from everything... power, antennas, etc. I could sit in my neighbor's house across the street during a storm and watch lightning strike my external antennas (65' high) on my house multiple times during one afternoon thundershower.

 

Lightning does funny things sometimes, too. I've seen radios and stereo systems with nary a mark on them, yet every solid state component and most capacitors in the unit would be faulty. On the other side of the coin, I've seen units that looked like you set them out on your backyard grill for a few hours before bringing them in to the shop for repairs.

Edited August 13, 2014 by V.T. Eric Layton

[Pete!]

Old school:

 

In the '70s when computerized industrial equipment was expensive, we used a motor and generator set to supply safe power.

The connection to the outside power source was mechanical, not electrical.

Small surges would get absorbed by the flywheel effect of the rotating components.

Large surges might "smoke" the motor, but the electronics merely lost power.

[V.T. Eric Layton]

Pete, that sounds like a BIGGER version of the old lowly isolation transformer most techs had on their benches for testing equipment.

 

[Guest LilBambi]

Ah, the Variac...

[raymac46]

I remember using one of those Variacs to control the speeds on a paddle blade mixer and a high speed rotary homogenizer back in the food lab - a million years ago.

[amenditman]

OK, all you electronics geniuses, I have a question for you that fits right in with this thread.

 

I have a vague memory of being lectured by an octogenarian electrical engineer about electronics and power surges. Must have been sometime around 2000.

 

Gist of his lecture was that almost all consumer electronics had been beefed up to resist all but very large surges from the power system, or fairly distant lightning strikes. Local, like in your yard, lightning strikes could seriously mess up your gear. But he said that most electronic failures now are as a result of power sags, not surges. Sure the sag might be the result of a surge as the system attempts to restore power after having tried to shut it down.

 

Something to do with the power sag being a drop in voltage which is accompanied by an increase in amperage. The over amperage very likely to destroy the electronics.

 

Can one of you explain what he was talking about, since I've forgotten more than I remember of this lesson.

[V.T. Eric Layton]

As far as I know, power sags (these are nothing new, by the way) will not affect solid state devices. They cause the most harm to electro-mechanical devices such as electric motors, AC and refrigerator compressor units, etc.

 

No electronic device such as TVs or computers work on AC. They all work on DC. Variations in line voltage is regulated and smoothed out by the power supply units within electronic devices. A power supply is a device that converts AC line voltage to single or multiple DC output voltages. Most modern PSUs are isolated from the mains by using switching technology. The outputs are highly filtered and regulated. Minor deviations of voltage levels on the mains will usually not be felt at all at the outputs of the PSUs.

 

If a substantial loss in line voltage occurred, the PSU would just stop functioning at some point. Even older transformer/rectifier based power supplies could handle line sags. The output voltages were usually regulated by a solid state device (transistor array of some sort). Only very low voltages on the mains would severely affect the output of even these older power supplies.

 

Voltage increases on the line are a whole 'nother story, though. Small surges can usually be absorbed easily by the PSUs. Big ones, on the other hand, cause toasty components.

 

There you have it...

Edited August 14, 2014 by V.T. Eric Layton

[Cluttermagnet]

Just found this thread. This is a topic near and dear to me. Sorry about your loss of equipment, rejean.

I just skimmed through the comments fast, may have missed a little- but I want to say that Aryeh and

Fran have it basically right, i.e. there is no other protection that even approaches the effectiveness of

unplugging. But 'unplugging' is a trickier business than you might think. There can be sneak paths

during a nearby lightning event such that you *think* you are all unplugged and safe, and you actually

aren't.

 

I personally have lost computer parts to nearby lightning hits. One example was the time I had

power disconnected but had forgotten to unplug the phone line from the Winmodem inside the

tower. This was more than adequate to conduct energy inside where I think I remember losing

the modem and one or two other peripherals on that occasion.

 

Surge strips are what they are. They are not as complete protection as their makers would

have you believe- and in any case they can indeed degrade over time if the MOV's are

receiving high energy spikes fairly regularly. Further, if the strike is energetic enough, they

will not be adequate protection all of the time anyway. They may help, they may not. Doesn't

hurt to have them, usually, but I never count on them. BTW in some houses, equipment like

HVAC compressors, refrigerators, etc. can cause some pretty energetic spikes with great

regularity. Depends on your dwelling and the electrical grid and whether you happen to have

a next door neighbor who runs an electric welding machine in his basement. Some locations

can be quite 'spikey', most are not.

 

Here's the rule that should work most anywhere- if a long cable connects to a vulnerable

device, that cable represents a hazard during nearby lightning strikes and should be

disconnected. This covers the AC power line, telephone lines, coax cable of any sort,

and Ethernet cables. Here at my place and at Betty's, we spend a lot of time all summer

long disconnecting cables when we go out. The task is made easier if all your gear plugs

into a power strip- then you can pull just the plug from the power strip. I may have to go

and unplug at 3-4 locations around the house, but I just get used to it and try to remember

to do it almost without exception. Going out = disconnecting TV's and computers.

And guess what, guys- not a single lightning casualty in about 10+ years now, since

I adopted this firm policy.

 

BTW what constitutes 'long'? That depends, but generally a 1-6ft Ethernet cable

between your router and your cable modem is 'short'. Anything much longer than that

becomes questionable. A cable of 6ft length that is coiled up is less susceptible than

if it is laid out in a straight line for nearly 6ft. 'Short' cables probably won't get you in

trouble unless the lightning strikes your house or your next door neighbor. If there were

ever a nuclear explosion in the atmosphere, the resulting EMP event would probably

take out most any solid state device with any length of cable- like even 1ft. For EMP, your

box would need to be wrapped in foil and at ground level- or even buried, to survive.

Vacuum tube gear would fare much better in this event. But then the EMP would take

out the power grid anyway, so it's the same, effectively. Think of lightning as 'mini-EMP'.

They are both electromagnetic pulses. Lightning a block away- no problem. Right next

door- you're marginal.

 

One little 'gotcha' is any cables which may interconnect various boxes in a system-

think 'ground braids' like on coaxial cable. If you have enough of a 'daisy chain'

situation where device A connects to B connects to C, etc. eventually you may build

up enough cable length to have susceptibility to 'induction currents'. During the

few microseconds of a lightning event, metal chassis can develop thousands of

volts of electrical potential because they basically are 'floating' for lightning purposes,

they are not necessarily 'grounded' for lightning to the extent you might think they

are. Probably a lot of folks think of lightning as literally touching or striking a certain

conductor and then following it to ground (earth). What often really happens is

called 'induction'. Say the main strike is several houses up from you. You should be

safe then, right? NOPE! Lightning is so energetic it can induce currents in nearby

conductors, especially longer ones, without directly striking them. It is often these

'induction currents' which are quite strong enough to fry fragile silicon, that do all

the damage. Most lightning damage to fragile semiconductors is of the 'invisible'

variety. You may not see scorched plastic and exposed silicon as Aryeh did, yet

the damage is just as real and your device is just as dead.

 

It's mostly academic to us, as 'average consumers', but actually there are ways

of making an installation so secure that it can remain connected during a violent

storm, take direct hits, and survive. This is necessary at places like, say, a radio

transmitter site. In a nutshell, it is very costly and involves a whole bunch of

ground rods and buried wide copper ribbon entirely encircling the building. ALL

electrical connections into the building (NO exceptions!) must enter through a

single physical portal and be grounded to a metal bulkhead of copper- i.e. all lines

must be fitted with appropriate lightning arrestors that ground to the bulkhead.

If it's done right, the installation is near bulletproof and keeps on ticking, even while

sustaining direct strikes to, say, a nearby radio tower next to the building. Amazing

stuff but beyond the average consumer by a country mile. Puny 'surge protector'

strips? Better than nothing, but don't count on them much!

Edited August 31, 2014 by Cluttermagnet

[Cluttermagnet]

In addition to Eric's excellent comments I just want to add that there are so many 'sneak paths'

that can tickle your silicon with excessive voltage. Propagating through and overcoming the

regulators in electronic power supplies is but one way out of many. And yes, it's not the sags that

get you, although those can be bad enough, it's the spikes. Those spikes can ride in on any

long conductor including the power line. They can also bypass your normal electronic circuits

inside the gear, jumping randomly wherever they want to in their quest to discharge to ground

(earth). They still follow the same laws of physics inside your box, but not necessarily the

schematic (intended connections). For microseconds, the induced current can be quite enough

to create surprisingly high voltages across conductors. Semiconductors can be quite

fragile. For some, anything over a hundred volts can puncture them, and for some, even a

few tens of volts wound be more than enough to do damage. In a lot of gear, there will be

hundreds of thousands of semiconductor junctions- in many others, millions of them. Let

lightning currents in and something is probably going to give...

Edited August 31, 2014 by Cluttermagnet

[Cluttermagnet]

OK, all you electronics geniuses, I have a question for you that fits right in with this thread.

 

I have a vague memory of being lectured by an octogenarian electrical engineer about electronics and power surges. Must have been sometime around 2000.

 

Gist of his lecture was that almost all consumer electronics had been beefed up to resist all but very large surges from the power system, or fairly distant lightning strikes. Local, like in your yard, lightning strikes could seriously mess up your gear. But he said that most electronic failures now are as a result of power sags, not surges. Sure the sag might be the result of a surge as the system attempts to restore power after having tried to shut it down.

 

Something to do with the power sag being a drop in voltage which is accompanied by an increase in amperage. The over amperage very likely to destroy the electronics.

 

Can one of you explain what he was talking about, since I've forgotten more than I remember of this lesson.

 

I'm going to politely disagree with the gentleman, but this is not set up concretely enough to have a reasonable argument here. And he's not on hand to defend his views. No question sags do cause problems, though. Certain line voltage sags can be very hard on compressors and such. It's a lot easier to mitigate against sags affecting electronic gear. The answer is to deploy filters in spikey installations. These are different from those battery backup devices that are well known to computer users. These filters have series inductors and shunt capacitors and can mitigate against sags and spikes of 'short' duration, i.e. well shorter than one cycle or 1/60th of a second (here in North America). Google "Islatrol" for an example of a commercial product. I have several of those.

 

almost all consumer electronics had been beefed up to resist all but very large surges from the power system

 

True if you exclude nearby lightning. But we actually have a lot of lightning in North America. Most gear is ill-prepared to handle lightning. Unplug!

 

BTW let me hasten to add that, even when storms are near you, the odds are with you if you don't unplug. Electronics damage by lightning is pretty rare, but it sure does happen. Selling power strips is probably a multi million dollar industry- although they're a bit like snake oil IMO. Apparently a whole bunch of folks value the idea that surge strips might protect their gear.

Edited August 31, 2014 by Cluttermagnet

[amenditman]

I'm going to politely disagree with the gentleman, but this is not set up concretely enough to have a reasonable argument here. And he's not on hand to defend his views. No question sags do cause problems, though. Certain line voltage sags can be very hard on compressors and such. It's a lot easier to mitigate against sags affecting electronic gear. The answer is to deploy filters in spikey installations. These are different from those battery backup devices that are well known to computer users. These filters have series inductors and shunt capacitors and can mitigate against sags and spikes of 'short' duration, i.e. well shorter than one cycle or 1/60th of a second (here in North America). Google "Islatrol" for an example of a commercial product. I have several of those.

 

 

 

True if you exclude nearby lightning. But we actually have a lot of lightning in North America. Most gear is ill-prepared to handle lightning. Unplug!

 

BTW let me hasten to add that, even when storms are near you, the odds are with you if you don't unplug. Electronics damage by lightning is pretty rare, but it sure does happen. Selling power strips is probably a multi million dollar industry- although they're a bit like snake oil IMO. Apparently a whole bunch of folks value the idea that surge strips might protect their gear.

Is your Islatrol something like the power conditioners they sell for HD TV's? Big capacitors which all incoming power goes through?

 

 

Snake oil or no, surge protectors definitely sell. I think your estimate of the industries revenue is low by at least several factors of ten.

global surge protection devices market was valued at USD 1,890.5 million in 2013

[Cluttermagnet]

Is your Islatrol something like the power conditioners they sell for HD TV's? Big capacitors which all incoming power goes through?

 

 

Snake oil or no, surge protectors definitely sell. I think your estimate of the industries revenue is low by at least several factors of ten.

 

Sounds greatly over-hyped, to justify the well over 100 dollar price tag. I'd need to see schematics or read a true technical writeup. Don't know what they've got there. If the "advanced linear filtering" they refer to is the same as the L/C filtering I referred to, these would be of some value in mitigating some sags. MOV's of course can do nothing about sags, only spikes. There are no doubt some MOV's in it, too. The "improved audio/video clarity" claim sounds very doubtful to me. More hype than anything.

 

Automatic extreme voltage shutdown guards your valuable equipment from dangerous wiring faults

 

Note that they don't say a word about it helping with voltage spikes. It's probably just a relay that trips out on overvoltage. Probably no help on power line spikes caused by inductive load switching (refrigerator compressors, etc.) let alone lightning spikes. More hype.

 

I might buy this thing at half the price- but would be more likely to cobble something together myself. I'd buy an Islatrol, however. That's well proven protection, costs about as much, and is probably as good or a better buy IMO. They are pretty cheap on Ebay, used.

 

Zero ground contamination circuitry assures the delivery of pure AC power thus protecting critical audio/video components

 

Wow- what the heck is that? Makes little or no sense. Sounds like more hype.

 

Look at the enclosure. There is a little extra room for MOV's, maybe a relay, maybe a toroid dual inductor, maybe a tiny circuit board, maybe a sprinkling of bypass capacitors- but little else. I'd love to see a schematic of their 'zero ground contamination circuitry'- if it even exists. No idea what they mean here. Are these guys who sell 'surge strips' the carneys of the electronics sales world? Looks like... I'd LOVE to see a schematic!

 

Sounds like it may have an RFI filter at the input as well, before any L/C 'power conditioning' (filtering). Can be useful, but more of a solution in search of a problem. I'd be happy with the L/C filter only. (Islatrol) Now if you have a CBer next door, who runs illegal high power, then maybe an RFI filter might actually have some purpose...

Edited August 31, 2014 by Cluttermagnet

[Guest LilBambi]

Even UPS (uninterruptible power supplies) with AVR (automatic voltage regulation)/line conditioning can be damaged if hit by close lightning but often will protect the electronics/computers attached to them and if not, (if you sent in your warranty and saved your receipts) your equipment is often replaced by the insurance on these types of devices.

 

But they will ride out most storms quite nicely. Both on sags and spikes (within reason, not withstanding close lightning).

 

NOTE: I would only leave stuff on and plugged into the UPS with AVR/Line conditioning if you absolutely have to! You take your equipment's life in your hands if you don't shut down and unplug...

 

The biggest problem with all these devices is that if they are damaged, they often still appear to work...this goes for surge protectors and UPS with AVR/Line Conditioning. Although, the latter does a much better job of letting you know there's something wrong than a red button that may or may not be popped on surge protectors.

 

Here's an interesting article on When Does Poor Power Quality Cause Electronics Failures? - EC&M

Edited August 31, 2014 by LilBambi

[Capt.Crow]

If the polarity in your installation is correct , A simple workaround is to connect the neutral on the *wall socket *ie the one you use for your gear to earth and take another heavy line from that to a good ground in wet or damp soil outside the house . The neutral in the main box can also be reconfigured this way . BUT you must check with the local bye laws to make sure you are not in contravention .

 

This with a surge protector will give a great deal more protection .

[V.T. Eric Layton]

Here's something you can take to the bank, folks. If lightning has no difficulty jumping the gap between the clouds at 15,000 feet and the ground, then it will NEVER be burdened by a surge protector of any make, model, or type. A direct hit, or even a nearby hit, will happily blow chunks of concrete off the side of your house, even if you do have that spiffy zap-cap thing the power company charges you for every month. The ONLY true protection from lightning strikes and surges is 100% isolation; total disconnect from power, signal, and any other connection to the physical device.

 

[amenditman]

I've seen lightning break an 8" thick reinforced concrete slab with a single strike.

It's big, scary, and powerful.

[Cluttermagnet]

Yep- the moisture in the concrete is instantly converted to super heated steam. It's gotta go somewhere, so it cracks the concrete apart in order to vent. Happens in a fraction of a second. The strike is generally following the steel rebar inside the concrete.

 

My partner had her next door neighbors take a direct hit to their roof peak. She said it was deafening. Knocked pictures from her walls. It literally blew recently planted shrubbery out of the ground in front of the neighbors' house. The plants landed a good ways away from the house (tens of feet).

 

I researched a little on line to find a couple of really good sites to show you guys how professional lightning mitigation is done. If you are a cellular phone site or a radio or TV transmitter site, etc. you have got to stay on the air through the worst of it. The scheme to do this is a 'perimeter ground' around the building, lots of ground rods, and lots of expensive, wide copper strap buried in the ground. Then you add a copper bulkhead and route ALL cables past it and through lightning arrestors. If this is done right, you can 'stay on the air' while lightning is striking all around you. You will be immune to all but the most very energetic strikes of all. In that field they always talk in terms of percent confidence, etc. There are no absolute guarantees. Bottom line- effective lightning mitigation is ungodly expensive and beyond the means of most people. And that is why what Eric just said above is quite true. Disconnecting all cables gives you a very good chance of not losing a single electronic device during violent storms. Leaving cables connected means there is a small chance you may sustain lightning damage. Personally, I always try to remember to disconnect, for at least 6-8 months of the year.

 

http://www.dxsupply...._Protection.pdf

 

http://www.smithspow...s/media-library

 

Notice on the map of the US (first link)- Eric, being in central Florida, is truly in Lightning Hit Central!

 

These are some big copper bulkheads, of the type you'd see at a transmitter site. Notice the extra wide copper

straps going down from the panel to the underground perimeter ground strap. This is how the pros do it.

BTW the round, black thing is a big piece of coaxial cable; the smaller black is coax of maybe 1/2in diameter.

http://www.comm-omni...eb/polyapps.htm

 

Getting back to those modest 'surge strips', it's not that they are useless- they do afford some protection against some transients. So 'snake oil' is too strong a condemnation. But boy do they oversell those things! Greatly overhyped in terms of their actual capabilities and performance. I definitely do use MOV type strips here and L/C filters for power line conditioning- and I recommend them to others. But let's get real about how much they can actually do! If you unplug your devices when you go out or there is nearby lightning, you are way less likely to lose any gear to transient voltage spikes!

Edited September 1, 2014 by Cluttermagnet

[Guest LilBambi]

Yep. That is why we spend so much time shutting down and unplugging electronics.

 

We make it easy on ourselves though; those power strips really make it easier to 'unplug' more equipment at once.

[mac]

I've read several times about not plugging a UPS into a surge strip. True or not true?

[Pete!]

Slightly OT (Nothing to do with protecting electronics)

 

A few years ago, a tree near my stepson's house was struck by lightning.

A huge hole blew "up" through his basement floor.

The remainder of the house, and the electronic devices were unharmed.

We speculate about a strategically located root...

[Guest LilBambi]

I've read several times about not plugging a UPS into a surge strip. True or not true?

 

They say that; but I think they say that for true surge strips. But if you get one today that is just a power strip that extends and adds plugs that would be fine.

Edited September 1, 2014 by LilBambi

[Guest LilBambi]

Slightly OT (Nothing to do with protecting electronics)

 

A few years ago, a tree near my stepson's house was struck by lightning.

A huge hole blew "up" through his basement floor.

The remainder of the house, and the electronic devices were unharmed.

We speculate about a strategically located root...

 

Yeah, that does sound like a likely suspect.

[V.T. Eric Layton]

I have fond memories of being at work in my late teens and 20s and calling home when an afternoon storm was starting up to ask mom to check to make sure all my power and antenna connections were disconnected on all my radios on my bench in the shop. I can still hear her bitching as she would bend down to look under the bench at all the connectors under there. Usually , they were all disconnected. Sometimes, though, I'd forget. Mom was well-versed on what needed doing if that was the case.