Questions about GU10 50W Dimmable Bulbs & Power Consumpt

[subzero]

Hi

We have had recently installed 8 x 50w dimmable GU10 ceiling lights on the same circuit.

Question 1
Can these all be driven off the same dimmer switch (currently on a normal on/off switch)

Question 2
Since the power consumption at maximum is high (400w), will dimming the circuit to 50% reduce the consumption accordingly to 200w, or does it not work like that?


Also, I've just discovered about LED light fittings (with driver). Obviously these are not dimmable but only 3w consumption which are much cheaper to run. Just wondered if anyone has had any experience with these?


Many thanks for your advice

 

[flameport]

1 - Yes, but this will require a suitably rated dimmer which can be used with 400W of halogen lighting. A majority of dimmers will not be suitable, even if they are 400W. You will also need a much deeper backbox as the dimmer will get rather hot when in use.

2 - No, dimming the light so it looks half as bright will use almost as much power as when full on. If you reduce the power consumed by 50%, the lights would be very dim indeed. Essentially, dimmers are useless for saving energy.

Some LEDs can be dimmed, most cheap ones can't be.
Regardless of who makes them, a 3W led will be nothing like a 50W halogen.

A possible replacement would be the Philips Master LED 7W, warm white, 40 degree.
However they are 81mm long so much longer than halogen lamps.
They are also expensive at around £30 each.

 

[subzero]

Brilliant (no pun intended). That's cleared up my questions nicely!
Many thanks

 

[ban-all-sheds]

We have had recently installed 8 x 50w dimmable GU10 ceiling lights on the same circuit.

And you're regretting it already?

Question 1
Can these all be driven off the same dimmer switch (currently on a normal on/off switch)

Yes but

• Dimmers rated at that capacity can be noisy.
• Dimming halogen lamps shortens their lives - google "halogen cycle".
• As per flameports answer to Q2 it doesn't work like that.
  
  It works like this