I got a power switch which seems to have minimal load that makes it incompatible with LED lights.

Schneider GUPA1411BSS 1 Gang 1 Way PIR Switch — after unpacking I found it has only L, L1 and earth connections and a min load of 20W (220v). When mounted it fails to fully power my led light which are probably around 16W and is buzzing (lights blinking).

Product page at https://www.schneider-electric.co.uk/en/product/GUPA1411BSS/ultimate-screwless-flat-plate---occupancy-sensor-with-override---flush---2-wire-/ seems to miss that aspect.

Is there something I can do to make it work?

Updated info from the instrusctions:

Rating 230V ~50Hz Max Load 150W/150VA Min Load 20W/50VA

When using 12V electronic transformers, ensure that the minimum load on the circuit is no lower than the approximately 70% of the rated transformer load i.e. for a 65VA transformer, the minimum load would be 50W.

The transformer that I have on the LED lights seems to be 35W but I have no idea which is the effective load. It came with the lights and it has a feature where if powered down-and-up <5s it would switch the LEDs to dimmed mode. Sadly I can no longer reach the transformer a huge mess in the ceiling as the light panel was glued to it, so I am looking for a solution on the light switch side (wall).

  • \$\begingroup\$ Dump or waste some power through a resistor in parallel... \$\endgroup\$ – Solar Mike Apr 6 '19 at 8:13

That unit uses a two-wire connection so it relies on being able to pass a little current through the load while "off". The load resistance needs to be low enough that enough current can pass without a large voltage drop across the load and without turning on the load. They have chosen 20 W.

Options are adding in a parallel load, using a > 20 W lamp or, possibly, a capacitor load. The capacitor would pass some current but since this would be out of phase with the voltage it would not get hot. Whether or not the switch would like this or not is impossible to say.

  • \$\begingroup\$ Resistor approach seems dangerous due to heating. Also I just realised that my led lights are in fact 36W so maybe the switch is broken as clearly 36W is far above 20W. Maybe there is another reason why they marked it as not led compatible. I should probably return it. Sadly I was not able to find anything similar that looks ok. (light switch with pir sensor). \$\endgroup\$ – sorin Apr 6 '19 at 9:22
  • \$\begingroup\$ The LEDs won't conduct significantly until you get close to working voltage. \$\endgroup\$ – Transistor Apr 6 '19 at 15:38

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