Lightning Surge Damage

[Michael15956]

Recent completed job.

Interior bonding on the water pipe. No bonding of the water pipe within five feet of the pipe's entrance. Also, no grounding rod existed. Maybe if the bonding was install to today standards and a grounding rod was installed there may have not been any damages.

New panel

All circuits megged and only damage was cause to the armor cable circuit. All appliances with electronic circuit boards without surge protector suffered damage,TV/Microwave/Garage door opener/Clothes dryer etc. Appliances with surge protectors did not suffer any damages.

 

[StephenSDH]

Thanks for the pictures. Nice Panel:smile:

 

[al hildenbrand]

Wow!

I love the burn along the joist following the lay of the AC cable!

Was that a Wadsworth circuit breaker center?

 

[tom baker]

Thank you thats very dramatic. I'll send to Mike Holt.
Perhaps the moral to this is lightning is trying to get to earth. thats what the ground rod(s) are for. We bond to the interior piping and electrical to minimize flashover.

 

[raider1]

Great pictures Michael.

I also found it interesting to see the burn track on the floor joist where the AC cable was attached.

I also found it interesting to see that the water pipe clamp was burned off where the wire was connected.

Chris

 

[Michael15956]

Wow!

I love the burn along the joist following the lay of the AC cable!

Was that a Wadsworth circuit breaker center?

Yes, the old panel was Wadsworth.

 

[Michael15956]

Great pictures Michael.

I also found it interesting to see the burn track on the floor joist where the AC cable was attached.

I also found it interesting to see that the water pipe clamp was burned off where the wire was connected.

Chris

I wonder Chris, if the water pipe clamp did not burned open would there be any damage on the armor cable? Like Tom wrote it seems like the surge was just trying to find a way to earth and maybe once the clamp broke open it ran on the armor cable which was just about all burnt.

 

[al hildenbrand]

Yes, the old panel was Wadsworth.

Some of the more memorable plasma arc displays I've seen have been "sustained" by Wadsworth breakers. Thank goodness I don't see many of them around here.

 

[hurk27]

The one thing I see that scares me, is that the generator can back feed the panel with the main on. no isolation/transfer switch, just a two pole on/off switch. zoom in on the JB box to the right and you can see the switch says "transfer switch" above it, and the receptacle says "generator plug" above it. "widow maker type hook up"
but I see you removed it.

I have seen a few houses hit by lightning, one that hit the peek of the roof leaving a 8 foot hole, and then followed the rain down the surface of the roof to the gutter where at one end of the gutter it passed by where all the home runs went down the outside wall to reach the panel, it blew off all the sheathing and insulation off the NM romex leaving just bare copper wire in the wall, the drywall board was blown off the wall down on top of a 12 year old boy sleeping, scaring him half to death. But just before reaching the panel, it arced over to the RG11 coming in from the cable company. it took out all the cable line amps in the neighborhood. even when there was two ground rods and a water grounding electrode connected to this panel. It did damage all the cable box's and took out two front end (tuners) of a couple of TV's connected directly to the cable system, but that was all the damage it did, no TV's or other electronics was damaged
But this is normal of lightning because of the high frequency nature of a lightning strike. The impedance of a common lightning strike based upon the most common center frequency of 10 meg. hz. will raise a few eyebrows when you do the calculations for 15 to 20 feet of #6 wire to a ground rod, almost infinity. this is why we see lightning taking other paths many times, other than going to the rod. once I saw lightning hit a 15 foot tall tree that was just a few feet from a 300 foot radio tower, the tower had many 50 foot ground rods and ground rings bonded to it, but the lightning just couldn't see it and saw the tree. with branches of many different lengths, its like a broad band antennae.

Lightning is a field all of its own to learn.
just thought I'd throw this in here to help you understand what your up against when dealing with lightning.
Wayne:wink:

 

[mxslick]

Michael, thanks for sharing those pics.. very odd that the romex didn't suffer any damage.

Wayne, thanks for your post as well..very informative..and yeah, lightning does do some very strange things..