by ericmark »
Sat Nov 04, 2017 11:02 am
Unless one of the inverter fridge/freezers then you need to consider it at 10 amp when working out volt drop, and volt drop is important with a fridge/freezer, what you say you want does not seem to exceed 13A, if 13A or under simple FCU will do the job, one in house with 13A fuse and a switched one in shed with 3A fuse for lights.
Once over 13A then another ball park.
So 13A you are right on the edge using 2.5 SWA cable it would be good for 53 meters, power not lights, I would be looking at 6 mm SWA as it is common size so not too expensive and it would allow more power latter if required.
6mm is slightly too small for 32A volt drop wise but with a 32A supply it is unlikely you would use full 32A so close enough. For lights 6mm would need a 20 amp supply, however although 3% volt drop is limit for lights, with LED they would still work with the 5% allowed for power.
So I would likely use 6mm cable with 20A MCB in house consumer unit which would allow for electric heating, and within the 5% volt drop for lighting.
However you need to inspect and test and sign paper work to say you have designed, installed and inspected and tested, so you need to work out volt drop and likely earth loop impedance not me, personally I would use three core and use a copper earth, but your designing so you need to work it out not me.
