What size cable

[JOHNBOY42]

My brother is getting his garden flagged next week he has a shed down the bottom of it about 20ft away and would like a feed to it so he is going to put it in soon so it cab be buried under the flags with a coil to be left at the shed and coil to be left at the gable end where cu is on other side of the wall ready for a spark to connect ... what size cable does he need and would this be able to be put in conduit or does it have to be armoured cable ......... there will be a fridge in there ,lights and will be using a lawnmower/strimmer

 

[bernardgreen]

Put a duct in and then the electrician can pull in the cable that he decides is the necessary size.

 

[ericmark]

As @bernardgreen has said, we need to consider volt drop, and loop impedance, likely 1.5 mm² is enough to run a fridge, and garden tools, but we select to match protection, so a B16 MCB in the consumer unit needs 5 x 16 amp to trip in under 0.1 seconds, so needs 80 amp to trip, add 5% for safety so the loop impedance needs to be 2.73 Ω or less, for a TN-C-S supply of 100 amp, the supply is likely 0.35 Ω so need cable to be less than 2.38 Ω, but that is assuming a TN-C-S supply, all this will likely be completely incomprehensible to you, which does not really matter, as the point is your not in a position to work it out.

I know with my own garden as it stands supply to out buildings could be very light, but latter may want to charge an electric vehicle, so more considerations, including loss of PEN I have included links should you want to learn more.

So likely I will lay a heavier cable to allow for future needs.

 

[JOHNBOY42]

Thanks for all replies ... he has decided to put 10mm armoured cable in ....possibly overkill