Dimmer switch advice please

You need the bigger one and even that will probably be overloaded as LV halogens present a more challenging load than incandescent.

Have you considered replacing the lighting with something less environmentally disastrous? 550W of lighting in one domestic room emits an unacceptable amount of CO2. Dimming lights reduces their light output, but does not substantially reduce the energy use.

Christian.

Dimming lights reduces their light output, but

If it does not reduce the energy then what makes the light go dim?

You need to check on the maximum loading for LV type loads - they aren't always the same as for GLS lamps.

It reduces the energy *slightly*.

You might be using 90% of energy but getting 40% of brightness. In other words the lights are even more inefficient when dimmed.

Owain

No you dont, need and want are 2 different things.

how many degrees C does that heat the room up by in summer? Having once had a 500w heater, dont remember exactly but several C at least. They inflict it upon themselves.

Why not be sensible and use a switchbank instead. Or be even more sensible and use lighting that doesnt eat 550w, heat your kitchen up, dazzle anyone leaning back in the chair/sofa, and produce dead bulbs faster than the whole of the rest of the house put together.

Working out what those lights cost to run is enough to put a lot of people off, they'll eat thousands of quid over the years.

NT

More important is to use electronic transformers that can interpret the dimmer switches correctly. I THINK that LV toroids don't work well with dimmers.

Fairly wrong actually.

Depends on the dimmer - toroids tend to have a high inrush current which calls for a higher rated triac than might otherwise do. And not all SMPS are suitable for dimming. Both the 'transformer' and dimmer need to be said to be suitable for the job, and the instructions followed.