Hey folks! I'm new to working with electrical switch boxes and I'm trying to set up a Shelly Mini relay Gen 4 to automate one of my recessed lights while still being able to use the physical switch. My house is pretty new, built last year, so I thought there would be a neutral wire at the switch. But upon opening the switch box, I only found hot wires and ground—no neutral wire at all. The left switch (where I want to put the relay) has three wires, and the other is a 3-way switch with four wires, but they all seem to be hots and grounds.
If I can't find a neutral at the switch, I'm thinking about installing the relay at the light fixture where I can find a neutral, but then I'd lose the connection to the SW port on the relay, which means I'd lose control from the physical switch.
So I'm reaching out for any help! Can I install the relay and keep both smart and manual control without running new wires? Should I be looking at a different Shelly model for my setup? I'm open to any wiring tips or diagrams you guys could share. I've attached a link to the Shelly relay and some images for reference.
1 Answer
Hey! It sounds like you might have a bundle of neutral wires hidden in the back of your switch box. Typically, standard switches don’t have neutrals connected directly, but they do splice into the neutral that goes to the light.
Here's how to proceed if you’ve got those neutrals:
- Connect the incoming hot wire to the L terminal of the Shelly relay.
- Splice the bundle of white wires (your neutral) to the N terminal on your Shelly.
- Disconnect the wire from the switch that goes to the light, and connect it to the O terminal of the Shelly.
- If your Shelly has an I terminal, wire that to the same incoming hot as L.
- Finally, connect a short jumper from the switched load output of the switch to the SW terminal on the relay.
Also, remember to use a non-contact voltage tester to ensure everything is safe before you start messing with wires. Setting it up as an edge device could make it easier to program too! Good luck!
Hey, good call on the voltage tester—Kaiweets is solid! For wire gauge, most jumpers should match what you currently have. If your wires look thicker, go for 16 AWG; if they’re thinner, stick with 18 AWG. Brands like Southwire or Ancor are reliable. I can definitely help sketch out a diagram for you too!