this inside the main service panel outside. Most all the grounds are like this. . House built 2018. There are no chemicals or a pool around. panel is outside and completely out in the open. I am noticing the 14gauge show this discoloration a little further back from the bus than the 12gauge. neutrals and other conductors look normal. I’m guessing from lightning strike? what say you?
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Thats odd that its only grounding conductors. When I have seen lightning strike discoloration, it was all the neutrals too.
And they were a little blackened. These ones just appear to be oxidizing
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Rodents relieving themselves in and around the panel can do this too. The different size wires won’t be quite the same (different batches and maybe even brands) so they may tarnish at different rates whatever the cause.
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Here is a fairly recent and related post. Sounds like you might have read this post since you mentioned no chemicals or pool around. Chinese drywall was mentioned as a possible culprit. Not sure if this helps…
https://forum.nachi.org/t/blued-ground-wires/236820
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It’s also odd that it appears to only be on the horizontal parts of the run and also appears to be worse lower in the box. Of course, more pictures may change that.
Seems to me to be some kind of chemical in the air that is slightly heavier than air. It would build up in lower areas. How about the bottom parts of the discolored parts of the wire? Is it even in that area too?
If you’ve seen anything after an electrical strike, it’s not subtle. Stuff is usually burnt, blown apart and a complete mess. This doesn’t look like that at all.
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Thank You everyone for the input. It is such a clean panel otherwise. There are a couple of GFCI breakers in the panel that are not easily resetting and a couple of other things electrically related so I’m going to refer this out to A Professional Sparky to evaluate this…without being too much of an alarmist.
That was not caused by lightning. They discoloration is consistent with heat over a much longer period of time than they would have been subjected to in the short span of a lightning strike,
I would check the torque on the terminals first. If the terminals were properly torqued I’d move on the next most likely cause.
Electricians are notorious for indiscriminately tying grounded conductors together, which can cause grounded conductors to carry the load from more than one circuit. A Gauss meter will aid in detecting the presence of misrouted grounded conductors, but it won’t tell you exactly where. You will need to start physically identifying circuit connections in junction boxes, switch boxes and so on.
Very few electricians learn good troubleshooting skills. Someone skilled at troubleshooting electrical problems should be able to track down the cause within an hour or so, depending on how easy it is to get to the places where you need to look. I suggest starting with identifying home runs and working back from there to the nearest junction boxes. That’s where you will most likely find the problem.
I’ve done many hundreds, if not thousands, of electrical investigations. You’d probably be surprised at the number of houses with wiring errors in places where home inspectors never look. Misrouted grounded conductors ranks very high in the list of causes of a variety of electrical problems.
Back to the question of lightning, we have to consider what is happening during a lightning strike. First, bear in mind that a lightning strike is non-sinusoidal, so the stuff electricians learn about electricity mostly doesn’t apply. That’s why most forensic electrical investigators are electrical engineers, not electricians. A relatively small percentage of us are both qualified as an electrician and an electrical engineer. Next, lightning is a static discharge that contains a lot energy, but it is extremely high Voltage and relatively low current.
Hitting something with a very high sudden Voltage is like hitting it with a hammer or an explosive device detonating. Of course, the energy dissipates as heat, but it dissipates so fast there’s not enough time to cause the metal to absorb it.
Moisture in the air or in objects that contain a lot of moisture, such as trees will absorb most of the heat and much of it will be dissipated into the surrounding air.
Lightning also causes carbon deposits in and on components such as circuit breaker housings. You can usually use your finger, a white cloth, or a piece of adhesive tape to look for carbon deposits and carbon tracking. Individual components can be tested with a megger or a high-pot.
One thing I never do is to suggest to the they call just any electrician. They should call someone who does forensic electrical analysis. We have training and experience that most electricians never have. Electricians are trained to be mechanics, not diagnosticians.
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A 97 YO lady was in her home when lightning struck it a few weeks back. She saw the flash, heard the boom, went back to watching TV.
She’s a spry 97 but the neighbors look out for her and have her door code. A neighbor ran over, and got her out safely.
The fire department got it put out fairly quickly.
Because she knows the area, she bought the house 3 doors down and I inspected it for her.
As I was leaving I stopped by for a minute and got a video. Here is her home after the lightning strike.
This is a 360 Video, you can view any angle, just spin it around.
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That’s what I’m talking about. That is consistent with a direct strike, which is explosive. Another thing that I should have mentioned in my earlier comments is that often damage from lighting is not from a direct strike. It can be induced or it could have traveled a long distance across utility lines.
People who live in areas where there is a lot of lightning activity will often have damaged electronics and appliances with no visible damage to either the damaged items or to the structure.
You can say that again!
There were bits of shingles and wood blasted down the street and into the neighbor’s homes and such. Very energetic. Fortunately no gas utility in the attic, which is common in some of the other neighborhoods built 4-5 years later, not far away.
All the talk about grounded conductors and the issue shown was on grounding conductors.