12kv Primary fall on 120/240v Overhead triplex

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Sierrasparky

Senior Member
Location
USA
Occupation
Electrician ,contractor
Have a customer who had a 12kv primary fall on their overhead service.
Damage to the service for sure. Some switches let the smoke out as well as lights.

I am concerned as to what branch circuit wiring is damaged in the walls.
Mega ohm readings IMHO wont show much unless insulation is melted and wires almost touching.

Any thoughts
 
Location
Massachusetts
Occupation
Electrician
Have a customer who had a 12kv primary fall on their overhead service.
Damage to the service for sure. Some switches let the smoke out as well as lights.

I am concerned as to what branch circuit wiring is damaged in the walls.
Mega ohm readings IMHO wont show much unless insulation is melted and wires almost touching.

Any thoughts
If you smoked switches because of the 12kv entering the house, I'd rewire the entire house

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masterinbama

Senior Member
I would push the insurer for a total rewire also.

Or have them put in writing that their opinion supersedes your professional opinion, and they will assume future liabilities.

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drcampbell

Senior Member
Location
The Motor City, Michigan USA
Occupation
Registered Professional Engineer
I wouldn't presuppose what a megger will show without trying it first. If insulation has been depolymerized, it's likely to show up on a megger.
Then again, I wouldn't assume that all's well just because it passed a megger test for a few minutes.
 

hbiss

EC, Westchester, New York NEC: 2014
Location
Hawthorne, New York NEC: 2014
Occupation
EC
Had exactly that happen a number of years ago during a bad ice storm. Homeowner was a nut case, couldn't understand why other houses were having their power restored and he wasn't. Wife called me. He wouldn't let me into the house to look at the panel (I know it was an old Zinsco) but I did look outside and saw that the service drop, SE and meter were charcoal. I told him he would have to have his entire service replaced and I wouldn't trust any wiring in the house. He wouldn't believe me. He kept calling the POCO to restore his power.

Finally, after about two weeks without heat and power he got the message and found another local EC who replaced the service and (I guess) the panel. Now the nutcase refuses to allow an inspector in his house. The local cable news catches wind of the situation and sends a reporter and video crew to the house to show the wife all wrapped up in blankets with a candle and blaming the POCO for them not having power for almost a month. Of course the reporter agrees and blames the POCO too. Why are these poor people still without power?

The husband still refuses an inspection but the news coverage must have put pressure on the POCO. So the next day POCO arrives with the fire department standing by and re-connects them.

No smoke, but apparently they lost all their electrical appliances and TVs. No way I would want to live in that house after that with that wiring. A few years later the house was demolished to make way for a new one. I would have wanted to watch as the wiring was exposed to see the condition of it. It was the old cloth covered NM without ground.

-Hal
 

Sierrasparky

Senior Member
Location
USA
Occupation
Electrician ,contractor
Wiring was mega Ohm'd. Shows ok, I just am uncomfortable when a standard toggle switch smoked , charred the wall as one of the several notable things.
 

texie

Senior Member
Location
Fort Collins, Colorado
Occupation
Electrician, Contractor, Inspector
This kind of thing happens more often than many realize. In extreme cases, sometimes the entire structure is lost due to fire. I would not trust any part of the wiring system after having that kind of voltage imposed on it.
 

jaggedben

Senior Member
Location
Northern California
Occupation
Solar and Energy Storage Installer
I would push the insurer for a total rewire also.

Or have them put in writing that their opinion supersedes your professional opinion, and they will assume future liabilities.

This. They'll probably pay you to rewire. And in the perhaps unlikely event that they decide instead to provide you with a release of liability, it could be worth paying a lawyer for an hour to look it over and make sure they are really doing that.
 
This. They'll probably pay you to rewire. And in the perhaps unlikely event that they decide instead to provide you with a release of liability, it could be worth paying a lawyer for an hour to look it over and make sure they are really doing that.
Guys, I don't see how one would face liability for looking at a job, making a recommendation, and having the client not hire you to do the work.
 

yuhong

Member
Location
Burnaby, BC
Had exactly that happen a number of years ago during a bad ice storm. Homeowner was a nut case, couldn't understand why other houses were having their power restored and he wasn't. Wife called me. He wouldn't let me into the house to look at the panel (I know it was an old Zinsco) but I did look outside and saw that the service drop, SE and meter were charcoal. I told him he would have to have his entire service replaced and I wouldn't trust any wiring in the house. He wouldn't believe me. He kept calling the POCO to restore his power.

Finally, after about two weeks without heat and power he got the message and found another local EC who replaced the service and (I guess) the panel. Now the nutcase refuses to allow an inspector in his house. The local cable news catches wind of the situation and sends a reporter and video crew to the house to show the wife all wrapped up in blankets with a candle and blaming the POCO for them not having power for almost a month. Of course the reporter agrees and blames the POCO too. Why are these poor people still without power?

The husband still refuses an inspection but the news coverage must have put pressure on the POCO. So the next day POCO arrives with the fire department standing by and re-connects them.

No smoke, but apparently they lost all their electrical appliances and TVs. No way I would want to live in that house after that with that wiring. A few years later the house was demolished to make way for a new one. I would have wanted to watch as the wiring was exposed to see the condition of it. It was the old cloth covered NM without ground.

-Hal
I wonder how much it would have taken to rewire the house and whether the homeowner could have afforded it. Even changing the service drop and panel etc probably costs thousands.
 
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hillbilly1

Senior Member
Location
North Georgia mountains
Occupation
Owner/electrical contractor
I had one job where a car accident knocked the high line down onto a parking lot pole light, smoked the wires back to the contactors. Apparently didn’t bridge the contactors though, because they didn’t lose any electronics in the store.
 

jaggedben

Senior Member
Location
Northern California
Occupation
Solar and Energy Storage Installer
Guys, I don't see how one would face liability for looking at a job, making a recommendation, and having the client not hire you to do the work.

That's not what anyone was saying. It's as soon as you do any work that they can pin all liability on you if you don't get them to agree that you're not liable for what you recommended but they didn't elect to pay for.
 
That's not what anyone was saying. It's as soon as you do any work that they can pin all liability on you if you don't get them to agree that you're not liable for what you recommended but they didn't elect to pay for.
Eh,. Find something else to worry about:. Flouride, PVC water pipes,. New car smell off gassing, non organic foods, gmo foods, which ice cream flavor to get.....😉
 

hbiss

EC, Westchester, New York NEC: 2014
Location
Hawthorne, New York NEC: 2014
Occupation
EC
I wonder how much it would have taken to rewire the house and whether the homeowner could have afforded it. Even changing the service drop and panel etc probably costs thousands.

Oh, he could have afforded it. How much work would it have taken? Answer is in that they tore the place down a year or two later when he and his wife both died. The nasty old coot was a hoarder. I think his first dime was in there someplace.

-Hal
 
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