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[oblivious]

can anyone help with a few questions

1 what is the current carrying capacity of 6mm 3c SWA

2 this cable supplies my new garage and is 40 metres long can i install a 32A ring main and 6A lighting ccts using a 63A RCD

hope this is understood
thanks

[thedoctor]

Firstly please see our projectv on Part P of the building regulations. It is against the law to contravene these regulations and, as well as being extremely dangerous your home insurance and resale ability may be affected. An electrician will look at your question later.

[oblivious]

it states on part P project that these regs do not apply in scotland yet ,is this still the case ?
thanks
from scotland

[thedoctor]

Scotland has its own version of electrical regulations, please check with your local authority.

[sparx]

Hi, SWA /PVC 6mm 'clipped direct' on surface is rated at 49A, on a metal cable tray or 'in free air' is 53A, so your supply end MCB would have to be no larger than a 45A unit.
If using SWA/XLPE insulation then figs become 62A &66A respectively, so could use 60 A fuse or just abt.63A MCB.
Assuming the latter, the max load on system would be 30A max due to excess volt drop over the distance, so in fact a 32A mcb /rcd combination would be sufficient, fitted at supply end (house) with the lights fed from a fused connection unit (Fused-Spur) from ring.
To achieve your max load would need a 10mm2 cable, hope this helps, regards SPARX