Zen51 with no switch

My brain is not wanting to work today.

I have my landscape lights attached to a transformer which is hard-wired into the 120v run from the panel box. There is no switch on the 120v line. I have been using the photocell in the transformer; but it is becoming unreliable. I want to setup the transformer to use hubitats sunrise/sunset rules to turn on/off the power on that transformer.

I have a Zen51 laying here, unused. But I'm confused on how to wire it when there is not a switch in the mix; or if that is even possible.

  1. Is it possible?
  2. Am I using the wrong hardware device (is something other than zen51 better for this application?).

Here is the image from Zooz:

Without a switch; could I just tie together the black, blue and yellow from the Zen51 to the always hot black on the 120v line? White to white (to white) for neutral? And then red to the hot line on the transformer?

Should be possible - I'm doing something kinda similar with my bath fan.

Think of the 51's L and N as just the power input it needs for itself to operate. Then (in this case) the In and Out are just for what you want it to control. It so happens that L and In are both 120v in this case, so they both pigtail from the incoming line hot.

Out would be your load hot to transformer. Just cap the S1 (yellow) wire - it's not used in this case.


Ahhh yes.. capping. That makes perfect sense.
I could not work out where the yellow should go.. because it shouldn't go anywhere.

I just want to be clear in case anyone visits in the future.
The "L" is for the incoming line HOT (usually black in US).
The "N" is for the incoming line NEUTRAL (usually white in US).
Yes, they should both attach to the incoming feed.

Thank you very much!!

Yep, in summary - in the image above, pretend the transformer is the light, and wire everything just like they show, except there's no wires going to any switch, so you'll cap yellow instead of attaching it to anything.

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As @hydro311 says, capping yellow is the best option... but it would have also worked as you proposed. The yellow wire detects the presence/absence of voltage when the switch changes state. Whether you cap it (no voltage, ever) or wire nut it to the incoming hot (always 120 v present) the device will behave the same.

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Beautifully said. Thank you for the explanation.

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