Power Surge Question - Should I be worried?


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Old 03-20-17, 10:17 AM
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Power Surge Question - Should I be worried?

I had the craziest experience this past Saturday night. A tree limb fell on a power line across the street; on one of the main feeder lines, not a service line to a house. It did not break the line, but was just hanging there and causing sparks every now and then. This happened in the middle of the night and all of the interior lights in my house were off for the night. The power went out, but during the course of the power being out there were three or four events that I will call "surges," where there was a very sudden very loud noise and all of the lights in the house flashed on. They flashed on and off in the blink of an eye, and I wouldn't have believed it but it happened several times and happened both when I was upstairs and downstairs in the house.

The only reasonable explanation I can think of is that somehow all of the neutral lines went hot during the surge. Something that I am guessing should not be happening. Does anyone have any other explanation? And if not any advice on how to proceed to confirm this and resolve the problem? I appreciate any thoughts.
 
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Old 03-20-17, 10:45 AM
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If the power company was not called last night.... they should be called immediately on their emergency repair number. This type of problem should always be reported to the power company.

We'd be guessing if we tried to explain the problem with no information.
I can tell you that it is not a short to neutral. That is similar to a dead short and you wouldn't see that. It sounds more like a high voltage broken problem since you were/are seeing sparks.
 

Last edited by PJmax; 03-20-17 at 11:07 AM. Reason: typos
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Old 03-20-17, 10:53 AM
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[edit:] Just re-read your post after reading Pete's response. If the lights were switched off and still flashed a few times, then that would not be what I described below. Follow Pete's advice.



Highly unlikely for neutrals to be energized as they are bonded to earth ground at every single home. Even if it did happen somehow, it wouldn't cause your lights to flash unless the hot leg happened to be grounded.

More likely what you observed was the utility company trying to reenergize the line before all the problems were cleared. That can happen when multiple problems affect the same line.

Most often it happens right after the failure as some utility equipment will automatically reclose circuit breakers because many faults are temporary (like squirrels or wind caused branch contacts) and clear themselves.

But I've experienced a similar situation during a big storm when there were many downed trees. The power came on briefly a few times over several hours before coming back on for good.

It's always a good idea to check all your surge protectors after a power outage; most now have an indicator light to show the surge protection is still working. Also check equipment like sump pumps and the like that could be damaged without it being immediately evident.

Other than that, I don't think you have anything to be worried about.
 
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Old 03-20-17, 02:06 PM
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The power company came and cleared the branch within a surprisingly short time (whole thing from start to end was maybe an hour), and power restored shortly thereafter. The "sparks" were outside at the branch, not inside. And maybe "sparks" isn't the best term; looked more like embers, falling through the air under the lines, and was only a few. No recognizable problems since the power restoration, but I will definitely check the sump pumps. As far as I have seen, none of the surge protectors nor any of the breakers flipped during the event.
 
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Old 03-20-17, 02:17 PM
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That would have been caused by a broken primary wire. You very well could have seen sparks with those embers as the voltage is quite high and can easily ignite flammables where it arcs.
 
 

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