DIYbanter - View Single Post - 'Best' MCB rating for boiler + washing machine?

ARW

On 13/07/2019 10:54, wrote:
But would you agree with me that in certain cable run situations, the cable cross sectional area is increased if it's going through thermally insulated routes instead of surface clipped to the wall and the MCB is not uprated as a result....

Ditto for extra longer cable routes to keep the voltage drop to less than 3%?

It's not clear from the OP if this circuit was already present or whether he created this new circuit?

I totally agree that if the CCC of the cable is exceeded then the MCB
rating must be lowered (subject to known loads) or the CSA of the cable
must be increased.

Your example is a good one. A 4mm radial is good for 32A but if the
cables passes through insulation then it might have to become a 20A radial.

--
Adam