Which is the same answer as you get from the Wiring Regulations.
Sparkingchip, I think you have missed the point that Regulation 411.3.3 only applies where protection against overload is required. It's arguably not required for a shower (although see my earlier post, I would prefer it).
However, I'd agree it makes not a blind bit of difference if the shower manufacturer is recommending a B40, and also if you take into account frequent overload and loading factors for the CU and adjacent mcb's …I would never select In < Ib.
Which is the same answer as you get from the Wiring Regulations.
Sparkingchip, I think you have missed the point that Regulation 411.3.3 only applies where protection against overload is required. It's arguably not required for a shower (although see my earlier post, I would prefer it).
However, I'd agree it makes not a blind bit of difference if the shower manufacturer is recommending a B40, and also if you take into account frequent overload and loading factors for the CU and adjacent mcb's …I would never select In < Ib.
