Anyone ever seen this practice before? First time I’ve ever seen this. Copper wire wrapped around the ends of the conductor in a coil pattern.
Newer Siemens panel.
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What was the wire size. Less than 2/0 AWG? Maybe the electrician learned by waching tik-tok videos.
What you have in your picture—taking one individual strand (or perhaps a few) from the bundle and winding/wrapping it spirally around the outside of the main bundle at the tip to “make it bigger” and hold everything together—sounds like a makeshift or improvised hack some people use in specific scenarios, but it’s not typical for main feeder or branch circuit terminations in panels. I’ve seen this done in stupid tik tok or facebook videos. people are trolling for clicks and don’t care if they are hateful or supportive. It’s a numbers game.
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Listed/approved methods for UL-listed mechanical lugs (like those on main breakers or branch breakers) rely on the wire being inserted as-is (after tight twisting/grooming of the entire bundle). Adding an external wrap of a single strand could:
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Create an uneven diameter → poor fit in the lug hole/slot.
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Cause the wrapped strand to catch, break, or push out during insertion/tightening.
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Potentially reduce contact area or create a weak point (the wrapped strand might not compress evenly under the set screw).
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Violate manufacturer instructions (most breakers/panels specify bare stranded conductor prep via twisting only, no additions like this).
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For code-compliant residential/commercial panel work (NEC/NFPA 70), stick to:
- Strip → tight twist the bundle → full insertion → torque to spec.
That’s the reliable, low-risk way to avoid loose strands, hot spots, or ridicule from InterNachi inspectors.
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Nope, but I’m sure there’s a technical reason preventing the use of it, one being the inability to achieve proper torque of the conductors within the coiled conductor.
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I’m with Bert. “improvised hack” describes it best.
Do you have pictures of all of the interior of panel? It’d be interesting to see what else they did.
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Same.
My thought is they did it to try and fill the hole as much as possible. Actually would be a much better connection if they just twisted the strands a bit and torqued down the set screws to the appropriate level. The coiled part doesn’t even look like the same gauge as the strands.
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It’s just a dumb idea to coil conductors in an A.C. system. A coil is a choke (inductor). I guarantee that the person who did that has no idea what frequency it is tuned to, thus how much heat will be generated.
Coiling conductors is a National Electrical Code violation for a reason. The NEC specifically requires conductors to be routed to minimize inductive heating. While the inductive heating may be minimal, coiling conductors in an A.C. System is a bad idea in general.
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Panel called for 4 AWG at the Lugs.
I agree with you all. Coiling the wire like that was concerning. First for me. Surprisingly, no other issues noted. Other than not ground rods at the base of the sub panels. There were 3 panels that all had the same coil at the Lugs.
There were 2 other sub panels thst did not have this coil method and those looked good.
Plain ole hack work. They need to hire a properly trained, skilled electrician.
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If those subs weren’t in a separate structure, I would not expect to see ground rods at them. Or maybe I am misunderstanding your statement.
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Yeah, I’m sure. And it sounds like you agree?
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Reading comprehension issue for me… Rereading, you stated same building > no ground rod required. Yes, we agree.
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I knew we did. I was going to highlight my double negative, because I probably worded it not the best way. Should have made it more clear what I was saying.
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It is not entirely impossible that you have not incorrectly chosen your words.
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So, two home inspectors walk into a bar…
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After a few drinks, the first inspector says. “I have to take a piss”. On the way back, the second inspector asks, “Do you feel better?”
The first inspector replies, “No! The bathroom door rubs on the door jamb, the receptacle isn’t GFCI protected, the hot and cold faucets are switched, the sink drain is an S-trap, the water lines are polybutylene…..”
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I haven’t, but it almost looks like a helicoil that’s used to repair damaged threads.
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One other thing worth noting. If this is a sub-panel the conductors feeding it are a feeder. The thread title uses the term service conductor which is incorrect.
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Okay, sorry about that. I’ll cross my I’s and dot my T’s next time. 
Service Feeders.