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In electronics work I would never trust twisting together 3-5 wires in a pigtail to be a secure connection. On a breadboard mere contact is enough, but in (permanent) PCB work a connection that's not soldered is a connection waiting for a hiccup.

Yet in electrical work one is content with a pigtail using a wire-nut.

Conversely again in electronics, using the two sides of a receptacle to extend a connection to another receptacle downstream is safe and reliable.

Once again, in electrical work this is against code.

Suppose I follow my hunch and my habit, pull out my soldering iron and leave the twisted wires behind a receptacle with a soldered connection, which I would still cover up with a wire-nut (though wrapping with tape should also be adequate and plenty safe).

I'd be going over and above convention for my own peace of mind, but I'm wondering. Can I apply electronics knowledge to house wiring?

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  • diy.stackexchange.com/questions/179562/…
    – P2000
    Commented Dec 7, 2023 at 17:45
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    Basically no, you can not. There are a bunch of code requirements that you would never think of from electronics. But they are not especially hard to learn.
    – Ariel
    Commented Dec 7, 2023 at 21:13
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    "PCB work a connection that's not soldered is a connection waiting for a hiccup" Not at all. Think about edge connectors, USB ports, RF connectors, CPU sockets... Plenty of connector pins are crimped, particularly large gauge power connectors like Molex in your PC's power supply, and you should never solder a connection meant to be crimped.
    – user71659
    Commented Dec 7, 2023 at 22:50
  • @user71659 Right... I was comparing the "draft" one would do on a breadboard with the permanence of a PCB. There's one more variable missing. A connection failing on a breadboard is somewhat rare, but it's not unheard of.
    – Sam7919
    Commented Dec 8, 2023 at 0:55
  • @Sam7919 there are also pressfit PCB connections out there...
    – ThreePhaseEel
    Commented Dec 8, 2023 at 2:56

1 Answer 1

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Solder (with some very rare exceptions mostly having to do with knob&tube work) is forbidden in code because it causes problems. A wire nut is different than just "twisting some wires together." Soldering that is not "over and above" - when the connection overheats and the solder melts, the wirenut won't have proper compression and will fall off. Arcing will ensue.

Your assertion about receptacles is incorrect, or else you mean something other than what is normal standard practice using the screws on the sides of the receptacles. In the particular case of a MWBC, the neutral connections must be done with pigtails, for good reasons of electrical safety having to do with the specifics of a MWBC supplying 120V but having 240V potential available. Elsewhere (incuding the hots of a MWBC) it is normal and code compliant to connect to the downstream device from a set of screws on the upstream device.

Be very wary about "applying" low voltage electronics knowledge to line voltage house wiring. Indeed, be wary of applying line voltage electronics knowledge, if you have that, to house wiring. The issues are different in significant ways.

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  • We all get grumpy about the NEC at some point, but the fact is, these folks are writing code based on (among other things) mitigating fire risk.
    – Aloysius Defenestrate
    Commented Dec 7, 2023 at 22:29
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    Or, codes are written in blood. Make sure it is somebody else's, not yours.
    – Jon Custer
    Commented Dec 7, 2023 at 22:30

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