Last week lightining hit the ground near our house. Most electronic appliances with circuit boards were destroyed. We just received our new modem so I can use my daughters laptop.
We had a small fire in the wall, it made a three foot tall crack in the 5/8″ gyp. bd. We were lucky it extinguished itself because it took 25 minutes for the fire department to respond. They are located two miles away. The state police 911 operator did not give our local department correct directions.
The air conditioning unit needed a new capacitor and fan motor, the low voltage controls on the heating system and other units need to be replaced. Garage door openers were toasted. The damages were spread throughout the house.
Is anyone familiar with where an electrician should look for hidden damages or any methods to insure there are not any other burned wires due to the lightining surge?
Where can I get a small repair kit for two part 2# density spray foam ?
Untill I get another computer I can’t answer any questions right away.
Thanks
Replies
How big is your house? I'd want to take everything electrical apart and megger all the wiring. $$$
Where can I get a small repair kit for two part 2# density spray foam ?
Huh?
Ed
Edited 7/3/2007 11:54 pm ET by edlee
With the basement, main floor and loft it's about 6,800 square feet of space. Much of the wiring is covered in spray foam insulation.
Thats why I am looking for spray foam repair kit. The jolt blew a crater in the foam.
You don't need 2 part foam to fix that area. Just a can of Great Stuff from the hardware store is all you need. They use 2-part because it cures nearly instantly.
Rebuilding my home in Cypress, CA
Also a CRX fanatic!
Parenting has always been a mix of sage life advice and inexcusable laziness.
I have the cans of foam with the gun. I am a bit anal on how I fix things. If I can't get what I am looking for the gun foam is plan B.
Similar thing happened last weekend here. Around dinner time I heard a loud retort like a gun or a firecracker, I peered out and saw a puff of smoke across the street at my neighbours house. 10 minutes later, neighbour comes over and asks me if I have power. He tells me the cable wall plate exploded and started a small fire. We look up at the wires and see that the service to his house has pulled out of the transformer and the wires are drooping dangerously close to his truck. Utility restored power a few hours later.
"He tells me the cable wall plate exploded and started a small fire"NEC calls for cable/satellite/phone service to be grounded at the demarc point or as close to it as possible, per their methods. My guess is that the cable company either never grounded the service or the ground is insufficient. My satellite cables weren't grounded, either so I called and had them come back to do it.
"I cut this piece four times and it's still too short."
Even with proper grounding, a reasonably direct hit to the cable line would be sufficient to cause the type of damage described.
So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin
"a reasonably direct hit to the cable line"Reasonably direct? Is that like being "a little pregnant"? Close is good enough for lightning. It would be but at least some of it would have been directed elsewhere. How do you stop a few million volts? I worked on a house last year with lightning suppression and the electrician ran his bundle of Romex right next to the big, braided copper cables, then wire tied his stuff to them, to keep everything neat. I wish I had been there when the inspector "explained" things to him.
"I cut this piece four times and it's still too short."
Yeah, "close" is what I meant by "reasonably direct". You can get a hit to a power line a half-mile away and it will maybe fry electronics, but isn't likely to start a fire. And of course you can get a direct hit from a large bolt and ain't nothing gonna stay in its way. But there are lots of scenarios in-between, especially when you consider that there's probably a 100:1 variation (maybe 1000:1) in bolt strength.In the case of coax, the center conductor isn't grounded and often isn't even "protected", so if lightning gets to the center conductor it can cause arcing/heating in a splitter, or in the input stage of a TV set. And a large enough bolt can either burn through the ground wire or simply overpower it, causing high voltage (and significant current) to be transmitted on the shield.
So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklinmean
I would think that the best place for a strike to occur would be on the supply side of a transformer, since that's not only reducing the voltage but is also fused. After the transformer, it gets ugly."n the case of coax, the center conductor isn't grounded and often isn't even "protected",.."IIRC, most coax is rated to about 600V and once that's exceeded, blowing through the dielectric isn't far off.
"I cut this piece four times and it's still too short."
You can get arcing over between the supply side and load side of a transformer, plus there is capacitive coupling between the windings.Hard to say how high a voltage spike could be present on the coax center conductor. I'd be willing to bet that under realistic conditions you could get to about 2KV before there was insulation breakdown or arcing between conductors. Certainly sufficient to cause damage to other components. And, of course, regardless of the voltage the center conductor can probably sustain 30-100 amps current for the duration of a strike without burning through -- enough to really fry coils in spliters and input stages.
So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin
I'm not as worried about losing a bunch of splitters. Heck, if it saves my equipment, I want every splitter and surge suppressor in my house to fry, but nicely, with no fires. The ones I worry about are the kind that work for satellite, with the 14V, 18V or 20V power feed that doesn't go through a balun.
"I cut this piece four times and it's still too short."
I told him the same thing.
My cable and telephone were grounded properly when I re-built my house, but I'm not so sure about the satellite. Will be changing to Direct TV soon, so I'll make sure they do it.BTW, I landed at JFK last week in an amazing (and frightening) lightning storm.
You didn't see a furry guy peeling the skin back on one of the wings, did you?
"I cut this piece four times and it's still too short."
LOL. That was a great scene. Though the guy sitting across from me sure was freaking me out a little. I tried to pretend I was an air marshall.Next day I had to put my wife and daughter on a plane at JFK and the lightning came back again. They sat on the runway for 1 hour and waited for it to pass.
Shatner had a gun with him on the plane, IIRC.
"I cut this piece four times and it's still too short."
I was thinking about the movie with John Lithgow, I forgot about the Shatner original. I think he was in a few of them. I remember an early Robert Redford in one episode too.
"Shatner had a gun with him on the plane, IIRC."
Yep. And not only did he have a gun, he shot it through the window to nail the chimera who was "fixing" the starbord engine whilst in flight. As you know, due to his excellent marksmanship and uncanny ability to recognize dangerous situations and deal with them effectively, he went on to become a starship captain, where he used phasers instead of guns.
Mike HennessyPittsburgh, PA
As I recall, Shatner took the gun from someone else, like a police officer that was on the plane. But it has been years since I saw the episode.
It was a regular house current wire that exploded. The picture will show you the 3 foot tall crack it made in the wall.
All my grounds are correctly installed.
Unfortunately, it's hard to predict what might have been damaged. Have you determined how the jolt entered the house?
You probably need to follow it from the point of entry along every path that contains wiring, metal pipe, or some other metal (let-in metal cross-bracing, eg), and trace it out several connections beyond the last visible damage. Don't open walls necessarily, but look inside outlet openings, etc.
Devices like refrigerators can have damage to motor insulation, etc, without visible damage, and may fail a few months later. With electronics you're more likely to know it right away, though occasionally there can be latent damage.
I was home at the time. I believe it struck the ground near the underground electric service and traveled in to the house.
In that case you'd probably start by asking the electric company to come and pull the meter and inspect the wiring behind it. (Or an electrician may be allowed to do this where you live.)Then the sparky should open your breaker panel and inspect for any damage -- melted wiring or arcing. Pull several breakers and check behind for signs of arcing. The breaker on the burned circuit should be replaced in any event, and any others that don't seem/feel right. GFCIs should all be replaced, as should any built-in surge suppressors.The integrity of the ground wires from outside disconnect or inside breaker panel to your "grounding system" should be checked.A fair sample (maybe one in 4 or 5) of the outlet, switch, and light fixture boxes should be opened and checked for signs of arcing inside.The circuit that burned up needs to be carefully checked from the point of the fire back to the breaker panel, opening walls if necessary. High current could have melted wiring in the walls.
So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin
This is all good but I sure wouldn't want to rely solely on visual inspection.
As I said in my first post, I would use a megger to check the house wiring, concealed or otherwise, and I would also check continuities and voltages of a lot or all of the circuits, etc.
Ed
Yeah, a megger would be good too, though it's hard to get good readings on house wiring. Re continuity, that's kinda checked by default when you use the wiring -- you can't do any better with a meter unless you load the circuit to capacity. Likewise, checking voltage won't do much good -- if there's damage sufficient to affect voltage it'll be apparent in other ways.Would be a good time to have the sparky retighten the main connections at meter, disconnect, and panel, though.
So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin
The power company came out the same night and checked the meter and main panel. I did find today when I checked the next outlet over from the damaged one, the neutral wire had a small split in the insulation and the copper conductor is melted and brittle.
I have an electrician scheduled, I was waiting to see what else I discovered, so I don't have to keep recalling him.
"Devices like refrigerators can have damage to motor insulation, etc, without visible damage, and may fail a few months later. With electronics you're more likely to know it right away, though occasionally there can be latent damage."
This also happened to a customer of mine. Over the next few weeks, one by one the appliances started to act weird. Service guy came out and tested everything, I think every appliance had some sort of electrical issue; a couple of them crapped-out completely before too long. The insurance company paid.
-Norm
I guess I may be seeing my insurance adjuster often.
Ditto on what everybody said. Had a similar occurance, but with out fire. Be sure and check the breaker box connections as they can become loose after a strike and cause flickering and surges. Might want to invest in some surge protectors for equipment, or a whole house unit. Check your switch and outlet plates for arciing too.
Surge protectors did not work. One of the protectors had a warranty protection policy of up to $100,000 to cover damaged equipment. I will try to see how good their warranty really is.
I have been told with certain lightining strikes the surge protectors don't do much good.
No, standard surge protectors aren't a lot of good for a strike of the magnitude that you had. They simply can't absorb enough energy to prevent damage to the "protected" equipment.
So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin
I had a UL-compliant lightning protection system installed... lots of external copper, blunt aerials, and ground rods later, I think we might have a chance of surviving a direct hit without internal fires. Despite heavy-duty UPS/high-joule protectors/and 3 panel-based whole-house surge suppressors, I am under no illusion what a direct hit can do... I've seen too many pictures, read too many narratives. Disconnecting equipment is probably as close as it gets to protecting it, and even then, induced currents can fry whatever you have.... oh and why a lighting protection system? Well, we're on a hill and multiple trees in a 100' radius of the house have managed to play lightning pole. The latest hit blew out the entire crown of a 50' healthy Norway Maple. Pretty much killed the tree. Other trees around the house have/had scars in their bark that is consistent with lightning hits.
We are on a hill also. I also found out the firemen don't carry enough hose to reach our house.