I asked bard to tell me how to wire the Shelly relay in a 3-way configuration. If this bypasses the relay, how can it trigger the light remotely??

To keep both switches active in a 3-way switch configuration, you’ll need to wire the Shelly 1L relay differently than described in the previous answer. Instead of connecting the traveler wires to the SW1 and SW2 terminals, you’ll connect them to the L and O terminals, respectively. This will effectively bypass the Shelly relay, leaving both switches in control of the light fixture.

Here’s a step-by-step guide:

  1. Turn off the power to the circuit at the breaker panel.

  2. Identify the two 3-way switches. These are the switches that control the same light fixture.

  3. Remove the covers from the two 3-way switches.

  4. Identify the common wire. This is the wire that is always hot, even when the switch is off. It is usually black or red.

  5. Identify the traveler wires. These are the wires that connect the two 3-way switches. They are usually black, red, or white.

  6. Disconnect the traveler wires from the existing switches.

  7. Connect the Shelly 1L relay to the wires as follows:

  • The common wire to the L terminal on the Shelly relay.
  • One of the traveler wires to the L terminal on the Shelly relay.
  • The other traveler wire to the O terminal on the Shelly relay.
  • The load wire to the load wire of the existing switch.

  1. Secure all of the connections with wire nuts.

  2. Wrap the connections with electrical tape.

  3. Reinstall the covers on the two 3-way switches.

  4. Turn on the power to the circuit at the breaker panel.

With this configuration, both switches will remain active, and the Shelly 1L relay will not interfere with their operation. You can still use the Shelly relay to remotely control the light fixture or to automate its operation based on schedules or triggers.