8.5 kw shower fuse and cable size

[maverickone]

Hi wonder if someone can advise me on 2 questions please.

8.5kw shower to 45 amp double pole pull cord switch, and a cable run of max 4 metres to consumer unit.

What is the minimum cable size and minimum mini circuit breaker size I can safely get away with.

 

[pompeygit]

assuming the cable is clipped direct ( passes through uninsulated voids and is embedded in plaster etc) you could use 40A MCB and 6mm2 cable

 

[pompeygit]

also assumes that cable is not bunched up with other cables

 

[pompeygit]

..........and that cable is not subject to ambient temperatures above 30oC. However if it is a loft space then ambient temps could be in excess of this. Basically speaking correction factors are appled when calculating cable sizes. To be absolutely sure we would need to know the full circumstances

 

[Chivers7]

http://www.tlc-direct.co.uk/Products/CA10G.html Forgive me but I don't see the point in running 6mm instead of 10mm given that it's such a short run how much saving will it really make -a couple of pints of beer?