What wattage dimmer do i need - GU10 50w lights

[paulrushton]

Hi, Really simple question for someone out there. I have just wired up 8 x 50watt GU10 Downlighters in my front room. I currently have two switches (One by one door the other by the 2nd door). Each switch either turns them all on or off.

I think I need a two way dimmer (only replacing one switch) capable of handling the wattage which I would assume to be 400watt (8 x 50). I have however been told that because they are downlighters they double the voltage and would need a dimmer capable of halndling 800 watt.

Is this the case???

Thanks

 

[luminaire]

8 x 50 = 400W
Never heard of doubling it up for downlighters.
If you are installing downlighters you will undoubtedly be increasing the wattage on your lighting circuit which is normally protected by 6A mcb, so you don't really want to exceed about 1200W. If you do you might consider upgrading to a 10A mcb. Just be careful.

 

[fattony]

they dont double the voltage however when calculating the dimmer does need to be derated, Im not sure what the exact figure is but will find out, you will be looking at a 600w dimmer I think but need to double check

 

[RF Lighting]

Dimmers need to be rated between 25% - 50% above the load they will actually be switching when used with halogen lamps (and some other sorts too)

 

[paulrushton]

Ok thanks. If its max of 50% then i'll go for a 600 watt one to be safe.

 

[Taylortwocities]

Some dimmers do not need derating. See here : http://www.tlc-direct.co.uk/Technical/DataSheets/Systems/DimmerGuide.htm