Re: [OT] : wiring sockets ??

[patrick doocey <patrick.doocey@xxxxxxxxx>]

> I did a few checks yesterday and 2.5mm T&E seemed to be rated at
27A...

The 27A rating is "clipped direct", i.e. in the ceiling void,
etc. In
a wall, surrounded by conduit and plaster and possibly insulation,
it's much lower as it's more difficult for the heat to dissipate.

> But your argument still holds - thus I'm assuming that this is why you
> need much 'thicker' cable for radial circuits (e.g. Cooker, Shower)
> and even then the thickness is dependent upon the length of the cable
> being run.

Yep, a 32A radial circuit would need 4mm T+E, which is why 2.5 rings
have become the norm. The length becomes a factor because of voltage
drop over the length of the cable. Too long and the RCD won't
disconnect in less than the required 0.4s. If you use a thicker cable,
you can run a longer circuit.