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Anyone notice any wiring issues here? I know the housing wires are old.
This Main panel runs from the meter.

I have noticed occasional sparking here where the blue dots are. It causes the house to drain power or flicker lights, but never trips a breaker.
The power drain is house wide so its all breakers, not one.
Any ideas? This may be a better picture . The thick black wire that looks like strands is actually fully connected , the rest of the thick wires are hidden by a black tab

panel with the dead front removed & trouble spots highlighted

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    Sparking is not good. Main reason is a loose connection, so tightening is probably all that is needed. Do not know how you would turn off power completely to that panel for safe work, so wait for someone with more experience. Is that the main panel or a sub panel? If sub then might also need to have separate ground and neutra.
    – crip659
    May 19 at 18:27
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    You may want to replace the picture with one with arrows pointing toward the problem areas instead of dots covering the problem areas. Will make it much easier for the experts here to note any existing damage.
    – FreeMan
    May 19 at 18:39
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    It is obvious that your main neutral connection is loose, it can be tightened , make sure the wire is in the lug if burnt or melted conductors it should be trimmed and some material that is not damaged used, if the lug is melted they can be replaced for ~7$ . The neutral going to the UF cable looks ok it just needs to be tightened also. Use caution as you can get shocked from a neutral.
    – Ed Beal
    May 19 at 19:00
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    Can you turn that disconnect off, then post a photo of the label on the inside left of the panel cabinet please? May 20 at 0:10
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    Lotsa good diy advice here (that is, after all, cooked into the name), but even I (have rewired a k+t house, own a torque screwdriver, etc etc) would get a pro to fix this. May 20 at 3:21

5 Answers 5

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Shut 'er down, Clancy!

This is arcing. It can start a fire.

This was caused by someone not using a torque wrench to torque the lug to spec. (Don't repeat the mistake.)

Do take it out of service Right Now.

Worse, it's arcing off the neutral, which means voltages are going bananas downstream of it - the two 120V phases are adding up to 240v as they should, but instead of 120..120, they are 90..150, 200..40, 230..10, all over the map. So 120V things are getting wild voltages ranging from 0 to 240V, and I would expect ongoing appliance destruction and potential fires.

From the bentness of the lug, I gather it has already partially melted down and cannot be reused. The wire is ruined anyway from the heat, so you'll need to cut off the heat-damaged section (as evident from the state of the insulation). Follow Greg Hill's advice on a new lug to attach to that neutral bar.

Feel free to tighten it down just "gud-n-tite" if you want this problem to happen again. NEC 110.14 requires use of a torque wrench because of this.

It is aluminum wire, but there's absolutely nothing wrong with that. Aluminum is not at fault here. In fact, people not understanding the importance of lug torque was half of what gave aluminum its bad reputation! (The other half was using it on terminals not properly rated for aluminum, blame government pressure on UL. But breakers and panel lugs are properly rated.)

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  • Would you mind adding a photo to your answer identifying the lugs that need to properly torqued? May 22 at 7:45
  • @RockPaper Thanks for the edit. They all need to be torqued except the empty ones. May 22 at 21:40
  • You're very welcome. I'm confused as to what constitutes a "lug". Usually when I think of a "lug", I think of a lug nut. But I don't see any of those in the OP's photos. In the photos, I see a bunch of bolt heads (mostly slot heads, along with a few Phillips heads). Are the metal thingamajigs that the bolts compress called "lugs"? May 22 at 23:13
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Is it an optical illusion in the photo or is that black wire going into the 60 amp breaker mostly cut off with just 3 little strands actually making contact? If so, that ain't good either.

Either way, unless there is a disconnect upstream of this panel so you can safely kill all the power to it (and if it goes straight to the meter, sounds like there isn't), you'd probably be best to call an electrician. The wire you marked looks to be discolored from heating up, so it's probably loose and causing arcing. Hard to tell from the photo just how damaged it is, and whether you can just tighten it, or if it needs to be cut back and reconnected with some fresh wire.

Definitely something you want to get fixed ASAP.

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    It's the photo I took .I checked and the wires are secure .
    – Larry D
    May 19 at 20:02
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    It's an optical illusion. If you click the image to get the blown-up version, you can see that there's a black plastic tab of some sort partially obscuring the cable. May 21 at 1:35
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There’s no point trying to play forensic photo analyst but from what you’re saying and zooming in close on the blue dots, those look like loose connections. Especially the larger neutral connection to the bus bar — the large set-screw is driven at an angle.

There’s also corrosion or paint or god knows what on the strands. I can’t even tell if it’s aluminum or copper 🤷🏻‍♂️

Shut off the power to this panel at the disconnect and re-seat the loose connections. If the wires or terminals are badly corroded, mix up some water and baking soda and use a small wire brush (the smaller the better) dipped in the water-baking soda to clean off the corrosion.

Then reseat the wires. The panel label will probably have a torque specification for the lugs, if you have a torque wrench then you can tighten the lugs down exactly to spec. If you don’t have a torque wrench or there are no specs, you can tighten by hand until it’s nice and tight. A little overtight is better than loose for the large wire. The smaller wire needs to be tight also but if you over-tighten it too much, it will break.

Check every connection with the power off. Make sure that every wire in the panel is well-seated. Any wires that are broken or only partly connected should be reseated, including with a freshly cut end if necessary. If there are any aluminum wires, you should layer on some anti-oxidant paste before reseating. That will help prevent future corrosion.

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    OP stated that this is the "main panel that runs from the meter". Since there are a mix of neutral and grounds on the same bus bars, one would hope he's correct.
    – FreeMan
    May 19 at 18:41
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    @RibaldEddie The 60A bottom right is the feed to this panel. There is very likely not a separate disconnect, though there is a small possibility that there is one. If there isn't, then utility has to pull the meter to do any work with the feed to this panel. As far as I can tell, in addition to the known neutral problem, the black hot feed wire is hanging by a few threads - not good. May 19 at 18:56
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    @manassehkatz-Moving2Codidact either way the wiring in this panel doesn’t look great. May 19 at 19:16
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    The 30 -50-and two 20 amp breakers never have had an energy issue The main breaker 60 runs to the basement ( I'm assuming ) ,unless its the 50 ... but there is another main breaker to shut off all household electricity _ except for the power that is in main breaker panel - and that breaker goes to breaker box panel to the house with all household breakers ..It's a bit strange ..unless you view it . I didn't wire the house
    – Larry D
    May 19 at 21:32
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    @manassehkatz-Moving2Codidact no the power comes in from the right, this panel uses the rule-of-6 metric, with only 5 breakers it's within that code. May 20 at 1:21
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This looks like a "rule of six" panel:

  • there are lugs to the right of the breakers; conductors from these run under the partition to the right
  • a conductor from the top of the neutral bar also passes that partition
  • a flat surface, perhaps the cover of the meter compartment, is just visible at the right edge of the photo.

If it truly is a "rule of six" arrangement then there's no single disconnect. Instead, these five breakers taken together are the "main disconnect." One has to turn them all off in order to cut all power to the building. The bus bars remain energized.

So turn off all the breakers but leave them installed so the bus bars are covered. Remove the neutral wire from the lug at the bottom. The lug appears damaged, but it also looks removable. I think the wire is too small for this lug, which resulted in the screw being driven until it had fallen through the U-shape head of the lug.

Easiest fix may be to install a lug kit. Pictured below are a couple ideas. One has tabs which are secured into a pair of open small-gauge positions on the neutral bar; the other is installed by stacking it on top of the bus bar. The latter might be the better choice here because it'll accommodate wire insertion parallel to the bus bar rather than perpendicular to it. (photos: homedepot.com)

When purchasing a lug kit, verify that the lug is rated for the gauge of wire you have there.

lug kitlug kit

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I think that whole breaker panel could do with a tidy up. Probably best left to a licensed/qualified electrician, electricity can kill. I'm less familiar with U.S. wiring but sparking and arcing is bad, in general. Sparks are red hot pieces of metal that used to be your wiring or terminals. Arcing is plasma (blue flashes of light), it burns as hot as the surface of the sun. Poor connections will cause excess heat, especially if the copper strands are missing, fatigued, etc. The bottom most connection on the right hand side only appears to only have 3 strands, for what otherwise looks like a beefy cable (I think someone else pointed this out too). The fact your breaker doesn't trip, does not mean everything is fine. The circuit may not even be capable of passing enough current (energy) to meet the trip requirements.

I would suggest turning the power off.

I know this is a DIY Home Improvement site but some things ARE best left to the professionals. If you don't know what you're doing, don't do it. As for the lugs & wire gauge. Here in Australia at least, the conductor should take up 80% the tunnel as per the Standards "off memory". All electrical work here is to be carried out by a licensed electrician and signed certificates issued.

The blue dots also made it a bit hard to examine the connections underneath.

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