Loft & Aircon circuit

[Lectrician]

I new it was 1kw - just didn't click.

I don't like seeing 1362 fuses used for parts of fixed installs - my preference really.

Regards floor areas, it did used to be until quite recently 100 for rings, 50 for 4mm rads and 20 for 2.5 rads.

It has changed to 100 for rings, 75 for 4mm and 50 for 2.5mm

 

[mapj1]

Regards floor areas, it did used to be until quite recently 100 for rings, 50 for 4mm rads and 20 for 2.5 rads.

It has changed to 100 for rings, 75 for 4mm and 50 for 2.5mm

I'm getting old... I still can't see why if 32A is enough for 100msq in in the ring case, but only 75msq in the radial... Still, sensibly 2 16A radials = one 32A ring. Now all we need is to educate people that they need the same inrush, performance as the telly still takes 70A to degausss if on radial or ring, and so C type 16As are not a bad thing, if the earth impedance is low enough, or an RCD backs it up.. (perhaps this is why the earth core is not reduced in continental cables)

If you are worried about the cable rating, then you could make it a 20A C type breaker , and wire it as 4mm up to the loft, then put a few sockets on, and still not bother with the CU in the loft - seems like a recipe for confusion for future owners when it trips to have MCBS up there.
Do record what you have done and leave a note by the CU for any future electrician !

 

[ban-all-sheds]

I'm getting old... I still can't see why if 32A is enough for 100msq in in the ring case, but only 75msq in the radial

Take a deep breath, and repeat after me:

Do not look for logic, consistency or reason in the wiring regulations. That way lies madness.
Do not look for logic, consistency or reason in the wiring regulations. That way lies madness.
Do not look for logic, consistency or reason in the wiring regulations. That way lies madness.
Do not look for logic, consistency or reason in the wiring regulations. That way lies madness.
Do not look for logic, consistency or reason in the wiring regulations. That way lies madness.
Do not look for logic, consistency or reason in the wiring regulations. That way lies madness.
Do not look for logic, consistency or reason in the wiring regulations. That way lies madness.
Do not look for logic, consistency or reason in the wiring regulations. That way lies madness.
Do not look for logic, consistency or reason in the wiring regulations. That way lies madness.
Do not look for logic, consistency or reason in the wiring regulations. That way lies madness.
Do not look for logic, consistency or reason in the wiring regulations. That way lies madness.
Do not look for logic, consistency or reason in the wiring regulations. That way lies madness.