Wiring – Electrical: How to connect copper ground wire to metal wire passing through switch box

wiring

I'm replacing a light switch with a smart home keypad (Insteon KeypadLinc).

The wall receptacle has three conduits coming into it, each of which has three wires coming out: one in a black plastic sheath (line/load), one in a white plastic sheath (neutral), and one that is bare metal (which I think is ground). Here's what that looks like:

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The switch I'm installing has four wires that need to be hooked up: line, load, neutral and ground. For ground, it has a bare copper wire. (You can see it in the middle of the photo.)

I was able to hook up line, load and neutral just fine by using twist-on wire nuts to connect them to the right places, but I'm not sure what to do about the ground. The bare metal wires coming out of the conduits that feed into the receptacle exit through a hole in the top of the receptacle and continue their journey onwards to somewhere else, so they don't have an "end" that I can stick a twist-on wire nut on. How do I connect the end of my copper ground wire from the switch to one of those grounded metal wires?

As you can see, what I've done for now is I've made a little loop at the end of the copper wire and looped it around one of the metal wires. This "works", in the sense that my multimeter tells me that there's 120V between line and the copper ground wire, but obviously it's an awful connection and I need to do something better.

How do I connect these?

P.S. I don't think this is relevant, but here's what I've worked out all the wires coming into the box do:

  • Conduit #1: line from power source, neutral, ground
  • Conduit #2: load to ceiling fan, neutral, ground
  • Conduit #3: load to next thing in the circuit (maybe an outlet?), neutral, ground

Best Answer

Each of the 'conduits' as you say, have an uninsulated ground conductor. If there are three such 'conduits' then there has to be a splice joining them. Add your ground there.

I've installed many insteon devices before. The first thing I do, and my best advise, is to spread out all the wiring after removing he old switch and before installing the new, to know absolutely what you have to work with.

If you absolutely have to connect to a ground without cutting and splicing the original, I would recommend a split bolt. split bolt It's going to look weird as hell in an outlet box, but if you thoroughly clean/abrade the existing ground so it makes good contact, a split bolt should do the trick