Shelly 1 Gen4 and Gen3 wiring diagram

Every job, terminal by terminal

Written for the Shelly 1 Gen4. Where the Shelly 1 Gen3 differs, it's listed under the jobs.

1. Switch a light or appliance

   One circuit, switched through O

   Mains comes in on L and N, a short bridge feeds the relay input, and O carries the switched active out to the light. The existing wall switch lands on SW, so the physical switch keeps working alongside the app.

   Terminals for switch a light or appliance on the Shelly 1 Gen4

   Terminal	What it does here
   L	230 V active in
   N	Neutral in
   I	Relay feed, bridged from L
   O	Switched active out to the light or appliance
   SW	Existing wall switch

   Supply: 230 V~ 50 Hz

2. Switch an exhaust fan

   The fan's circuit, switched through O

   Mains comes in on L and N, a short bridge feeds the relay input, and O carries the switched active out to the fan. The fan's wall switch lands on SW, so it still turns the fan on and off. Shelly lists fans as inductive loads that need an RC snubber across the load.

   Terminals for switch an exhaust fan on the Shelly 1 Gen4

   Terminal	What it does here
   L	230 V active in
   N	Neutral in
   I	Relay feed, bridged from L
   O	Switched active out to the fan
   SW	The fan's wall switch

   Supply: 230 V~ 50 Hz

3. Pulse a garage door opener

   Dry contact to the opener's trigger input

   The opener only needs a brief contact closure across its trigger terminals, so O and I run as a dry contact, with no mains passing through them. L and N just power the relay. The push button on SW carries mains, so use a mains-rated button. In the Shelly app, turn on Auto off for the output with a short delay.

   Terminals for pulse a garage door opener on the Shelly 1 Gen4

   Terminal	What it does here
   O	Dry contact, one opener trigger terminal
   I	Dry contact, the other trigger terminal
   SW	Optional push button, mains-rated
   L	230 V active in, powers the relay only
   N	Neutral in

   Supply: 230 V~ 50 Hz

4. Switch an irrigation valve

   Dry contact in the valve's 24 V AC circuit

   The irrigation valve keeps its own 24 V AC plug-pack. One plug-pack lead lands on I, O runs to the valve, and the valve's other wire goes back to the plug-pack's common. O and I are a dry contact, so no mains passes through the valve circuit. L and N just power the relay.

   Terminals for switch an irrigation valve on the Shelly 1 Gen4

   Terminal	What it does here
   O	Dry contact, out to the valve
   I	Dry contact, from the 24 V AC plug-pack
   SW	Not used
   L	230 V active in, powers the relay only
   N	Neutral in

   Supply: 230 V~ 50 Hz

On the Shelly 1 Gen3

• An extra terminal

  12V

  Not used in this setup