Rating of light fittings for design current

[keycare]

Hi all,

I'm designing the runs for my ground floor lighting circuit. Some lamps are GU10 fittings with 11W CFL in them. They can only have a maximum of 50W GU10 bulbs. Do you still have to assume 100W per light fitting?

Regards

 

[baz1968]

You have to allow for the possibility of a lamp or fitting that may be changed and uprated in the future. Therefore it's best to allow 100watt per point with a max of 1200watt per 6 amp circuit as a rule of thumb.

 

[keycare]

You have to allow for the possibility of a lamp or fitting that may be changed and uprated in the future. Therefore it's best to allow 100watt per point with a max of 1200watt per 6 amp circuit as a rule of thumb.

Cheers.

However, due to low ceilings, my kitchen already has 9 GU10 style CFL fittings (x100W = 900W) and so far on the same circuit is the utility room, WC and study (total 1200W).

I need to add 1 light fitting for the TV room, and 4 light fittings for the lounge and 1 porch light. That's an extra 600W bringing me up to 1800W, with diversity on the whole lot, that is 1188W (just inside the limits but not taking into account correction factors).

How does diversity work when all 9 GU10 CFL fittings are operated with 1 switch?

Much appreciated.

BTW 150W tungsten bulbs are being phased out soon, how long before 100W bulbs are gone? Will that affect the regulations?

 

[GaryMo]

You have to allow for the possibility of a lamp or fitting that may be changed and uprated in the future. Therefore it's best to allow 100watt per point with a max of 1200watt per 6 amp circuit as a rule of thumb.

Not if the OP has numerous downlighters (points) already installed!

Keycare, if you have a room with downlighters then allow maximum wattage per fitting which would be 50 watts.
Baz is correct in relation to rooms with a single point though.

 

[keycare]

Splendid!

I am in the process of digesting various installation books but only have a copy of the 16th edition of the Wiring Regs. However, some scenarios don't appear to be covered at all