Add a Shelly: two-way switch, no neutral, instead of an impulse relay
A Shelly is a small relay that fits in a box. Unlike Hue, the circuit stays almost as it is: the Shelly sits between the switches and the lamp, and the old switched wire becomes its input. Usually only a few changes in one box are needed.
Guides
- Fit a Shelly 1 Mini behind a two-way switchA Shelly in a two-way circuit: both switches stay, the Shelly sits in the junction box. Wiring plan with L, N, SW and O, only a few changes.
- Shelly 1L without neutral on a two-way switchNo neutral in the box? The Shelly 1L Gen3 works without one. Wiring plan for the two-way switch, with a note on the Shelly Bypass.
- Shelly instead of an impulse relay: push buttons with a ShellyReplace the impulse relay with a Shelly: the push buttons stay, the Shelly takes over with a button input. Wiring plan for the junction box.
Devices and goals
Shelly behind the switches (with N)
Shelly 1 Mini Gen3 in the box or Shelly Pro 1 on the DIN rail. The switches stay; the switched wire becomes the Shelly’s input.
Needs: Live, neutral and the switched wire in one box.
Shelly 1L (no N)
Shelly 1L Gen3: works without neutral. Low-power LED lamps also need the Shelly Bypass at the lamp.
Needs: Live and the switched wire in one box.
Push buttons + Shelly
Push buttons at every switch position, a Shelly with a button input instead of the impulse relay.
Needs: One core from each button to the Shelly, plus live and neutral at the Shelly.
What fits which circuit?
Worked out for each textbook circuit: does it fit, and how many steps it takes.
| Installed today | Shelly behind the switches (with N) | Shelly 1L (no N) | Push buttons + Shelly |
|---|---|---|---|
| One-way | ✓ fits3 steps | ✓ fits2 steps | ✓ fits9 steps |
| Two-way with junction box | ✓ fits3 steps | ✓ fits3 steps | ✓ fits19 steps |
| Two-way, no junction box | ✓ fits5 steps | ✓ fits5 steps | ✓ fits11 steps |
| Intermediate | ✓ fits3 steps | ✓ fits3 steps | ✓ fits29 steps |
| Push buttons | ✗ doesn’t fit | ✗ doesn’t fit | ✓ fits10 steps |