Lightning Strike

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shortcircuit2

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South of Bawstin
Lightning hit a tree 50ft from a home and traveled in the home on the irrigation wiring in the ground nearby. The irrigation timeclock next to the service panel blew apart, and some of the branch circuit breakers in the service panel were tripped. A visual inspection shows that the irrigation timer suffered most of the damage. The circuit breakers reset without any problem.

What kind of testing if any should be done on the breakers that tripped from the lightning surge? Should they be replaced?

Any feedback on how others handle lightning hits to electrical systems would be helpfull.

Thanks, shortcircuit
 
I would replace the circuit breakers no matter what, while you are in there I would take a look at the bus bars and see if there is any deformities on them, if so replace the panel or the guts if you can.
 
I see that you posted this about 3 hours ago and it appears that everyone is hopping all over this one.
Maybe it's because there are no definitive answers. Damage from lightning strikes is so ambiguous. The tripped breakers are obviously from a current spike as a result of the voltage spike from the lightning. The think is, is that you know that the breakers didn't trip because of a short circuit so if the voltage spike originated from the lightning that voltage had to travel through the breaker to somewhere down stream so my concern is if there are any signs of arcing? I would check the convenience outlets and fixtures for damage. The problem then becomes if you can even locate anything at all as it may be like finding a needle in a haystack if there is any damage.
You may be able to check most of the receptacles and fixtures but may not be able to check junction boxes.

It would be by bet that you won't find a thing and will conclude that it was a waste of time looking. You just don't know.

I have often wondered if a house fire wasn't a result of a convenience outlet that may have been damaged by a previous lightning strike that partially charred the insulation of the outlet. The sometime at a later date there was enough humidity or some occurrence that cause the insulation to fail completely and start to arc resulting in a fire. It may sound stupid but?
 
Thepoteet said:
I would replace the circuit breakers no matter what, while you are in there I would take a look at the bus bars and see if there is any deformities on them, if so replace the panel or the guts if you can.
Click to expand...

Thanks for the feedback. There doesn't appear to be any damage to the panel bus and the breakers reset and turn on and off without any trouble at all. A garage door opener was damaged. Other than that, so far the damage was to the irrigation timer.
 
templdl said:
I see that you posted this about 3 hours ago and it appears that everyone is hopping all over this one.
Maybe it's because there are no definitive answers. Damage from lightning strikes is so ambiguous. The tripped breakers are obviously from a current spike as a result of the voltage spike from the lightning. The think is, is that you know that the breakers didn't trip because of a short circuit so if the voltage spike originated from the lightning that voltage had to travel through the breaker to somewhere down stream so my concern is if there are any signs of arcing? I would check the convenience outlets and fixtures for damage. The problem then becomes if you can even locate anything at all as it may be like finding a needle in a haystack if there is any damage.
You may be able to check most of the receptacles and fixtures but may not be able to check junction boxes.

It would be by bet that you won't find a thing and will conclude that it was a waste of time looking. You just don't know.

I have often wondered if a house fire wasn't a result of a convenience outlet that may have been damaged by a previous lightning strike that partially charred the insulation of the outlet. The sometime at a later date there was enough humidity or some occurrence that cause the insulation to fail completely and start to arc resulting in a fire. It may sound stupid but?
Click to expand...

Thanks for the feedback. Yes lightning damage is difficult to diagnose. Someone suggested to meg out the wiring suspected to sustain damage. This would be a difficult process wouldn't it?

In the past most of the damage I seen has been to sensitive electronics like TV's, computors, garage door openers, GFCI receptacles, burner controls, anything with a circuit board.

shortcircuit
 
just a thought, if you were to test each circuit with an AFCI breaker, IMO i think it would trip if there were damaged wire just be sure nothing is plugged into the circuit

then if it trips, try to isolate the problem area.

just my two cents
 
July 5th I had lightning at my home. Hit all three structures. So far over $5000 material damage plus two computers fried but under extended warrenty, likely $2-3000 more.

There's no telling where it hit but it traveled over power, telelphone, video, ethernet, and USB lines.

I have more surge equipment than 99%+ of the population and still got hit HARD! I hate to think what would have happened if I didn't have all that protection - house burned to the ground? We weren't home at the time.

RC
 
shortcircuit2 said:
Thanks for the feedback. Yes lightning damage is difficult to diagnose. Someone suggested to meg out the wiring suspected to sustain damage. This would be a difficult process wouldn't it?

In the past most of the damage I seen has been to sensitive electronics like TV's, computors, garage door openers, GFCI receptacles, burner controls, anything with a circuit board.

shortcircuit
Click to expand...

And don't forget about the stress that the megging itself can be on the system. You would have to assure that every connected load is removed before you even consider doing it. Depending upon the age of the structure I believe that the wire is rated 600v most likely but what about the devices? How does one do an insulation check. Using a common ohm meter may only show a catistrophic failure by showing any resistance reading at all instead of an open circuit as one would expect but other than that an ohm meter is basically useless. Then, what does one do other than doing something similar to a meg test where meggering is not suitable either.
I believe your background, common sense, experience will have to be applied to review the system. Removing devices from their boxes and inspecting them for signs of arcing would be a good start. As far as the breakers go, knowing breakers as I do I highly doubt of they were damaged or the stress of a lightning stick would be visible. You could take a voltage reading across the line and load side of the breaker while it is close and with a load of some degree to see if you can read a voltage. I there is one this would be considered a voltage drop that would indicate that ther is some resistance across the contacts. I would doubt if you would find anythng though. Damage to connected loads and electronics most likely will be the biggest concern as you have already discovered. They are not as forgiving as the wire and devices are.

Bottom line? Which you will be attempting to do is not a black and white issue. It is a very gray area where you're going to have to put your expertise to work.
 
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