Shelly Bypass

When using the device without a neutral wire, the Shelly 1L requires at least 20W of power consumption to operate. If the connected light has a smaller power consumption, then Shelly Bypass is needed for the device to work.

If you are installing a Shelly Bypass in a lighting circuit in the UK, you will need to attach the Shelly Bypass between the Output wire going to the lightbulb and the neutral going to the other side of the lightbulb. It will feel very unnatural to connect the wire this way. Most people in the UK have a ceiling rose or light fitting which allows the space for a Shelly Bypass. They are really small, being only 39 mm x 23 mm x 7 mm.

A Shelly Bypass is required where there is neutral wire and where the power consumption is less than 20 watts. If the load of the light is very low (typically, LED lights), you need to add some form of load, that's where the need of a bypass comes in!

Rather than turning off the light, the Shelly 1L and Shelly Dimmer 2, dim the light so low, it stops glowing, leaving a very small current flowing through the circuit of the Shelly Device to keep it running, even when the light is off.

No, you only need a Shelly Bypass where there is no Neutral wire.

If you have a Neutral wire you may wish to consider either the Shelly 1 or the Shelly 1PM unless you need the dimming function specifically.

When using the device without a neutral wire, the Shelly Dimmer 2 requires at least 10W of power consumption to operate. If the connected light has a smaller power consumption, then Shelly Bypass is needed for the device to work.