The existing cooker circuit is 6mm² on a B40. The customer wants to replace the free-standing cooker with 2 built-in ovens and an induction hob. Will each cable from cooker outlet to device need to be the full 6mm², (e.g HO7RN-F) or can I get away with anything smaller and more convenient (e.g. what's supplied with each oven/hob, if anything)? The final purchasing choice hasn't been made yet, so I don't know whether any of the devices will be suitable for a 13A plug/FCU, which can obviously accept a smaller cable.
I do take your point that while the L and N cores will be trying to melt out of their insulation, it is quite possible the CPC is trying to melt into one or other of them (which really would matter) rather than simply out of the jacket (which probably would not).
The more thickly insulated CPC is not so well cooled, so may reach a higher temperature, but the point I was making was that there is no insulation we care about on the CPC in twin and earth - the outer jacket although it is of course insulating, is not considered an insulation, but a mechanical protection, in the form of a sheath equivalent to double insulation ( the sort of clumsy definition you sometimes get when two committees develop standards independently and do not cross reference.)
If you do care about this then the the advice that the reduced CPC twin and earth is suitable for all possible PSSC values cannot be supported.
I do take your point that while the L and N cores will be trying to melt out of their insulation, it is quite possible the CPC is trying to melt into one or other of them (which really would matter) rather than simply out of the jacket (which probably would not).
The more thickly insulated CPC is not so well cooled, so may reach a higher temperature, but the point I was making was that there is no insulation we care about on the CPC in twin and earth - the outer jacket although it is of course insulating, is not considered an insulation, but a mechanical protection, in the form of a sheath equivalent to double insulation ( the sort of clumsy definition you sometimes get when two committees develop standards independently and do not cross reference.)
If you do care about this then the the advice that the reduced CPC twin and earth is suitable for all possible PSSC values cannot be supported.
