Cable Question

[plugwash]

Has anyone considered diversity?

In general I do not believe there is any diversity on a lighting circuit (and yes this means I think the guidelines in the regs are wrong). In my experiance when a house is fully occupied in the evening all of the lights are likely to be on at the same time.

A situation where a number of rooms have multiple independent lighting sets that aren't intended to be used together may be an expception to this but that's a pretty rare situation

 

[flameport]

The 1200W 'limit' is from the days when rewirable fuses were the normal item, 5A @ 240V being 1200W.

However, 30 light fittings on a single circuit is a poor design, the only real solutions are to split the existing wiring into 2 or more circuits, or install some other type of light fittings.

Using 2.5mnm cable won't work since you would have extreme difficulty fitting that into the terminals of a light fitting.
Attempting to convert the existing circuit into a ring, or some other compromised mess won't help either.

 

[ban-all-sheds]

In my experiance when a house is fully occupied in the evening all of the lights are likely to be on at the same time.

I suppose in some families this might happen, but I don't think it is "likely" that all the lights will be on at the same time because it is not likely that there will be people in every room at the same time. Even if it's just the bathroom(s)/loo(s) that aren't continuously occupied.

 

[MisterG]

Hi

Any reason you can't use 1.5mm cable?

That's what I specified when I had my lighting circuits rewired.

Regards

G