How a lightning strike effects a service

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To add some clarity
the place that was affected by the Lightning is a 2 story home that has a walkout basement
the Lightning entered through the foundation to the electrical panel and ran through the underground service

i would like to know if that would reasonably damage the entire home or just the lower portion of the house. The damage to the house is visible within the basement and to the service.
 
Lightning strikes are so large with regard to voltage and amperage that nothing man-made is truly designed to "weather" them unscathed. Pretty much the best you can hope for is that no one inside gets injured during the event.
 
Jesseferreira said:
i would like to know if that would reasonably damage the entire home or just the lower portion of the house. The damage to the house is visible within the basement and to the service..........
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Lightening can absolutely damage one part of a homes electrical system while leaving the rest seemingly unscathed- a receptacle termination may look fine but the cable feeding it could be cooked further down in the wall. That being said, there are no defined requirements for checking for surge damage, but it is a good idea to meg branch ckts, check all devices throughout the home, sub panels etc-looking for any surge related damage-burns, discoloration, lv crap that doesn't work anymore. Remember to document everything.
 
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user 100 said:
Lightening can absolutely damage one part of a homes electrical system while leaving the rest seemingly unscathed- a receptacle termination may look fine but the cable feeding it could be cooked further down in the wall. That being said, there are no defined requirements for checking for surge damage, but it is a good idea to meg branch ckts, check all devices throughout the home, sub panels etc-looking for any surge related damage-burns, discoloration, lv crap that doesn't work anymore. Remember to document everything.
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When there is gross evidence of damage such as the OP describes, any reputable insurance company should require a full rewire. You just don't know where damage may be hidden. In fact, doing the megger test, which would normally be done at 1000v for 600v rated conductors, might tip marginal conductors into failure. And let's say you do a test and everything looks good. Are you "certifying" that the wire is now fine for continued use or is someone else making that decision? If you're "guaranteeing" the wire, what happens when 3 years down the road there's an electrical fire that destroys half the house and the cause in pinpointed as wire showing clear evidence of lightning damage but was inaccessible because it was buried in the walls?
 
gadfly56 said:
When there is gross evidence of damage such as you describe, any reputable insurance company should require a full rewire. You just don't know where damage may be hidden. In fact, doing the megger test, which would normally be done at 1000v for 600v rated conductors, might tip marginal conductors into failure. And let's say you do a test and everything looks good. Are you "certifying" that the wire is now fine for continued use or is someone else making that decision? If you're "guaranteeing" the wire, what happens when 3 years down the road there's an electrical fire that destroys half the house and the cause in pinpointed as wire showing clear evidence of lightning damage but was inaccessible because it was buried in the walls?
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And the thread here is about looking for damage, not about insurance requiring any rewire. I'm pretty sure that is this case they did not- if they did the op wouldn't be asking about procedure after the fact. Or the op is offering to do testing in lieu of complete rewire. What if the ho doesn't have insurance? As for risk to us, that's why we are bonded/insured.:)


As for "tipping" marginal conductors over the edge, keep in mind the context here: the wiring may have been hit with 10's of thousands of volts w/ the strike already and leave it there if there can be no rewire for some reason and not test it and be totally unaware of any damage or replace it at great expense w/out testing, which may not be necessary, but it's a bad idea to test the insulation at a level it would have been able to handle pre strike?
 
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Jesseferreira said:
To add some clarity
the place that was affected by the Lightning is a 2 story home that has a walkout basement
the Lightning entered through the foundation to the electrical panel and ran through the underground service

i would like to know if that would reasonably damage the entire home or just the lower portion of the house. The damage to the house is visible within the basement and to the service.
Click to expand...

There's just no telling with lightning.
 
user 100 said:
And the thread here is about looking for damage, not about insurance requiring any rewire. I'm pretty sure that is this case they did not- if they did the op wouldn't be asking about procedure after the fact. Or the op is offering to do testing in lieu of complete rewire. What if the ho doesn't have insurance? As for risk to us, that's why we are bonded/insured.:)


As for "tipping" marginal conductors over the edge, keep in mind the context here: the wiring may have been hit with 10's of thousands of volts w/ the strike already and leave it there if there can be no rewire for some reason and not test it and be totally unaware of any damage or replace it at great expense w/out testing, which may not be necessary, but it's a bad idea to test the insulation at a level it would have been able to handle pre strike?
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But if you do testing all you really can guarantee is there is no faults at the present time in concealed wiring, but you would have no idea what insulation damage may have occured that is currently holding your test voltage.

I may make notes that certain items passed a particular test, but not directly state any other condition just that it passed a certain insulation resistance test. If it is not difficult to replace - it won't even get tested it will get replaced.
 
Jesseferreira said:
what are the meggering requirements for services after a lightning strike .
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Jesseferreira said:
the Lightning entered through the foundation to the electrical panel and ran through the underground service

i would like to know if that would reasonably damage the entire home or just the lower portion of the house. The damage to the house is visible within the basement and to the service.
Click to expand...


You say there is "visible" damage to the basement and service.

If it's visible I would say it needs to be replaced and I don't think the insurance company would turned down a claim.

There have been cases in this area (southeast) of ECs doing rewires and calling it lightning strikes and this gets the insurance companies upset. With visible damage this is the real thing and hard to argue with.

I would give a price to rewire the whole house and see where it goes.
 
mgookin said:
There's just no telling with lightning.
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About 20 years ago a friend of mine went on a call for a lightning strike. It had only been about 30 minutes since the strike. He opens the drop down stairs to the attic and this lets in enough air for a fire to start. He runs to the truck and gets a fire extinguisher and puts out the fire and calls the fire department.

Be carefull right after a strike.
 
I used to do a lot of lightning strike work when I was a contractor in Oklahoma.

Weirdest one: I was called to a home within a few minutes of the strike. It had struck the cable TV line, ripping the siding of the house down in a jagged edge about 2" wide x 12' long. Blew up the cable TV box. It also tripped the electric cooktop breaker, but I didn't find any other damage.

As I was there investigating the damage, the lady of the house began to cook dinner, using an aluminum fry pan that had been sitting on the burner. She started making gravy in the pan, adding floor and milk. Turned her back to put away the milk, went back to the stove, and the gravy was gone. The lightening had come through the CATV, through the 120v receptacle it was plugged into, back to the panel, and out through the electric cooktop. Blew a quarter sized hole through the fry pan.

Lightning does weird things :jawdrop:
 
growler said:
You say there is "visible" damage to the basement and service.

If it's visible I would say it needs to be replaced and I don't think the insurance company would turned down a claim.

There have been cases in this area (southeast) of ECs doing rewires and calling it lightning strikes and this gets the insurance companies upset. With visible damage this is the real thing and hard to argue with.
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:thumbsup:Thank you.

We don't know the extent of the damage other than unspecified at the panel and in the basement. IC's do not pay for a complete rw every time there is a strike in or near a building- it's really a judgement call dependent upon damage. I wasn't saying the other stuff should be done in ​every surge situation, just that sometimes a building doesn't need a complete overhaul because of a lightning hit and it's not a bad idea to check even when evidence of damage is lacking.
 
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I held back with the lightning stories but since someone else went there, here are some:

Lightning blew top 5' off a chimney, blew the spikes out of the ferells and laid the gutters neatly on the ground directly under where they left the 2nd story facia, blew out sheetrock nails on 2nd floor ceiling. Zero electrical damage. This was a brand new house days before CO. It hadn't even been lived in yet.

Two kids playing video games during thunderstorm and they get shocked. Both kids unconscious. EMS arrives and lightning hits again. EMS worker(s) get shocked.

Lady loading or unloading her dishwasher during a storm and she gets electrocuted. Don't know what electrical damage was in house.

As you can see, there can be significant strikes with all kinds of seemingly random damage, injuries and even death. Trying to predict what's going to be damaged or not is a craps shoot.
 
when I was a kid lightning hit our chimney. took out a bunch of bricks that ended up in the side yard. there was a TV antenna mast attached to the chimney. no problems with it or the TV in the house that was connected to it.

place I used to work for we supplied some equipment to an oil driller. custom controller. lightning came in through the service, entered an MCC and then blew out one of the MCC buckets and hit our control panel.

MCC was scrapped and replaced. Control panel had all kinds of burnt paint on it but the only serious damage was a couple MOVs that had to be replaced. ironically a few months after the system was repaired the whole project was shut down and all the equipment was pushed into a hole in the ground and covered with dirt.
 
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