Just out of curiosity what size cable would I need to feed the shed with to handle 32 amp single phase socket?
If you are going from the house box to the shed it would depend on how far away the shed is, obviously the further away the more cable thickness becomes an issue.
Another issue is, that generally there will not be only the one 32amp socket in the shed, as there will no doubt be a few 240V 10-15amp GPO's at each end and sides, lighting fixtures, possibly a fridge or so, maybe a compressor, drill etc. and it has to be thick enough to power all of these items.
I cannot remember exactly but here in Oz I think that (240V) ratings here are 2.5mm 20Amps, 6mm about 40Amps, 10mm about 60Amps and 16mm about 100Amps, but I could be wrong as it was a while since I had to find out. There are a few sparkies on this forum so they will probably give you better info than I can.
As mentioned before, these figures are probably valid for a shed a short distance from a house ie; maybe 8-10m, but if you are talking about 85-100m away then probably double the thickness for all the cables.
Your local sparky should be able to advise you of what size cable you need. Bear in mind that the majority of the installation cost will not be in the main cable, it will be in the labour, circuit breakers, RCD, boxes,cable conduit ect. so if I were you, I would get a cable that is double what you think you need as you can always utilize what you have got if it is larger, but if the main cable is too small it will cost a lot more to get a larger cable installed at a later stage should you require more power (if it is even possible!!), and as it was in my case, I had to put in another complete set of everything. Also get a sub-board box that is about 2 times larger than what you need. Much easier to work on and more room for expansion.
Lastly, another option may be to put in a 3 phase main cable with 3A/1N/1E and leave the 2 spare actives disconnected, and if at some later stage you want to go 3 phase then you can just change a few bits and the main cable from the house will not need replacing, which is what I should have done! At the time I thought to myself that I will never get 3 phase installed!
Did I ever get that wrong! Hope this helps.
Cheers
Ed.