I want to replace my current light switch with a TP Link HS220 (smart switch with dimmer), but I’m confused about current wiring.

I believe top wires go to the light and bottom is the source.

Am I right thinking top wires (black/red/white) are hot/load/neutral and bottom wires (black/white) are hot/load? If so, why is the top neutral pigtail with bottom load? Also, I don’t understand the pigtail and how the black is wired on the switch.

I have no idea when wiring was done, but house was built in 1970. I successfully installed others TP Link HS200 on the same floor.

Is it possible to install the TP Link HS220?

Wiring 1

Bottom wires (source?)

Top wires (going to light?)

TP Link HS220

1 Answer 1


Yes, this can be installed here

It appears that your installer was smart and not only provided neutral at the switchbox, but provided you with a nicely color-coded set of wires to work with, too. You'll just need a length of black #12 stranded THHN to pigtail the always-hots with, after trimming back and removing the length of always-hot black wire that goes past the screw. Attach the black stranded THHN to the black screw on the switch, then nut it in with the remaining black wires. The red wire then lands on the red screw on the smart-switch, and the existing white pigtail from the smart-switch goes to to the bundle of white wires. Last but not least, a grounding pigtail and screw need to be added to the back of this box, and the existing ground wires removed from the existing (mounting?) screw and nutted to the green grounding pigtails present. Once all that's done, button the box back up, turn the breaker back on, and enjoy your new smart dimmer!

  • 1
    Not posting my answer. Can't compete with this one... stay safe
    – JACK
    Commented May 2, 2020 at 0:26
  • Is #12 wire necessary? I believe all the wires are #14. It’s on a 15A 120V circuit. So, I pigtail the two blacks together as if they were one wire. From that pigtail, I run a length of wire to the black screw. The red goes to pink screw. Neutral goes in the pigtail with the 2 whites in the back and I fix the ground as you said. Commented May 2, 2020 at 1:07
  • About the current ground wires, why do I need to change it? It’s not safe? Commented May 2, 2020 at 1:28
  • @SimonArsenault -- if you can ensure that all wires in the circuit are #14, then you can use a 14AWG pigtail; I suggested 12AWG as a "universal donor". The ground wires need to be changed out because you're not supposed to use box mounting screws as grounding screws -- they don't make contact in quite the right way. Commented May 2, 2020 at 1:58
  • @SimonArsenault Yeah you never go wrong with #12, but feel free to match the breaker. On the ground screw, that should be a #10-32 screw. They sell green ones 10 for a buck, though any short 10-32 screw will do. They also sell green ones with pigtails pre-attached, but I wouldn't pay $3 for 10 of them. See a real hardware store and see if they sell em in singles. Commented May 2, 2020 at 2:18

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