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how do I connect the ground wires from my Kasa smart switches to the metal junction box? As shown in photos, the four screws at the back of the j box already have copper wires under. Can I just add a pigtail (straight not loop) to the second screw which already has a straight copper wire under the screw.. then the two ground wires from my two smart switches to the pigtail? ( see drawing)

If so the two straight copper wires under the second screw cannot be touching, is that correct?

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    That was really dumb of the previous installer to cut those ground wires so short. Only needed one long wire to wrap around one screw and using the remainder to wirenut them all together. Then you would have had free screws for you light switches.
    – DJ.
    Dec 15, 2023 at 19:37

2 Answers 2

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As NoSparksPlease suggests, loosen the cable clamp and give a gentle tug to see if you can gain any length. If you hit the jackpot, trim the long wires to a suitable length (no shorter than 6") and reattach them.

Otherwise, detach whichever ground remains the longest and use a wire nut or better connector to add a new jumper for the screw and your switch ground. If your new switch just has a screw, add two jumpers.

Wago-style clamping connectors would be very convenient here. Twisting wire nuts on securely when you can't see what's inside them is no fun.

Also fix up the remaining grounds so they're properly looped. One looks straight and one's a goofy spiral.

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  • @isherwood, Otherwise, detach whichever ground remains the longest and use a wire nut or better connector to add a new jumper for the screw and your switch ground. If your new switch just has a screw, add two jumpers, …………………. I added a revised drawing. Is this what you mean, if II find say the extreme right side screw has the longest copper wire? My switch grounds are built into the switches themselves (integral) Kasa ks205
    – Raffi
    Dec 15, 2023 at 20:45
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Do your smart switches have a ground wire or just a ground screw? Maybe edit your post adding the model of switch.

The requirement for grounding switches is different than grounding receptacles. For switches NEC 404.9(B)(1) allows switches with metal yokes to just be grounded by the mounting screws, but the instructions are part of UL/CSA/ETL Listing and must be complied with. So if the instructions require connecting a ground wire then you must.

"wires under the second screw cannot be touching" confuses me a little, probably because I can't see it clearly. If you are describing that the wire goes around the screw further than 360 degrees and crosses over itself, then you are right. Unwind it a little and tightened that screw, or use it for the pigtail isherwood describes. Only one wire per screw is allowed, so you can't do it as you drew it in your first picture.

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  • ….. it’s KASA KS205, with integral ground wires ( built into the switch). I revised my drawing based on if the extreme right screw has the longest wire. Is my drawing correct?
    – Raffi
    Dec 15, 2023 at 20:53
  • Your second drawing looks pretty good to me. Even using the longest existing ground wire you may need to use an additional two wire connector to extend it to the connector you show. Dec 15, 2023 at 20:59
  • You mean using two pigtails and two connectors if my existing ground is not long enough?… I added a second drawing.. is this correct
    – Raffi
    Dec 15, 2023 at 21:07
  • No, just that the existing ground wire may still be too short to connect a four wire properly you you may need to use a two wire connector such as an Ideal 30-1332S to extend the ground out to an easier to access point. Dec 15, 2023 at 21:24
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    Ok i added a third photo… so using 1 two-port connector and 1 4-port connectors. I also use two short ground wires .. correct?
    – Raffi
    Dec 15, 2023 at 21:31

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