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How should I best run coaxial and Cat6 cables behind a circuit breaker panel in my apartment?

I'm planning to run the Cat6 and coax cables in two 1 inch steel conduit tubes to a plastic panel a foot under the circuit breaker box. I'm also planning to place a layer of 5/8" drywall up against the back of the load center, between it and the 1" tubes. I'm expecting this to be OK for the Cat6 cables, but am not sure if the coaxial cables will pick up interference from the electric cables close by.

Thanks very much for any thoughts on the safety and possible signal interference of this approach.

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    Coaxial cable is shielded, Cat6 cable is not (well, indirectly by the twisting of the pairs). Guidance for running cable (shielded or unshielded) data/signal cables near electric mains wires says to run crossings perpendicular, not parallel wherever possible. That said... I've seen a lot of suboptimal install situations and have never seen a single one I could definitely point to electrical mains interference as the cause. YMMV. Oct 13, 2023 at 17:14
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    I"m curious, why are you running new coax in 2023?
    – jay613
    Oct 13, 2023 at 17:54
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    @jay613 Our current cable box takes coax as its input, and we were running lots of other wires as well so it was not much additional effort.
    – Rex Cramer
    Oct 13, 2023 at 21:15
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    @FreeMan Yes, it's an owned apartment.
    – Rex Cramer
    Oct 13, 2023 at 21:15
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    The back surface of the breaker panel is more than enough shielding all by itself, and then you're putting your cables inside steel conduit. It's overkill, but it won't hurt anything.
    – brhans
    Oct 14, 2023 at 2:46

2 Answers 2

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All the usual devices which use Cat6 or coax cables assume that the cables may be subject to 60Hz electrical noise or induced current. They should have no issues dealing with any of that noise on the cables. I don't see an issue with this routing. Given the number of cables you have, the conduits may be overfilled. I don't know your cable brand, so I'm just using generic diameters, but I show it close to 50% full with six Cat6 and a coax.

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  • Do conduit fill rules apply to low-voltage wiring? I mean, after a bit the conduit is too full to get another cable in there, but is heating really an issue?
    – FreeMan
    Oct 13, 2023 at 18:06
  • @FreeMan derating rules apply if you're running high-power PoE on them, as of a recent NEC revision, but fill rules are heat-based as well, and do not apply to low voltage cabling.
    – ickybus
    Oct 13, 2023 at 20:24
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    BICSI also has limits on conduit fill, with a formula that aims for 40% fill. bicsi.org/standards/bicsi-standards/resources/… for reference. Of course homes aren't subject to BICSI but it never hurts to follow the standards.
    – KMJ
    Oct 13, 2023 at 21:26
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Assuming you ground the conduits, they provide shielding to the cables inside them. Which mostly don't give a fig for what 50-60Hz signals are doing anyway, as they are designed to reject interference from them, but metallic conduit does act as an additional shield layer.

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  • But what guarantees the electric circuits don't also carry signals at other frequencies? I mean, there are networking over power products being sold and used... or - are we sure that the shielding is enough to ignore that?
    – einpoklum
    Oct 14, 2023 at 10:27
  • Network cables also reject signals from other network cables by design. Differential twisted pair signal processing means that not only do the cables cause the interfering signal to oppose itself every time the wires twist, at the end of the line the common mode signal picked up by both wires is thrown away, and only the differential signal that's applied at the transmission end is left to be decoded at the receiving end.
    – Ecnerwal
    Oct 14, 2023 at 11:46

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