Changing down csa of cable.

[Ewan Lindsay]

I have an existing 10mm T+E running from the DB1 on a 20Amp mcb to the Porch, this joins onto a 4mm SWA that runs out to supply the Garage DB2.


Is it ok for the conducter size to change down ? As the cable has adequate protection from 20A MCB at source.

 

[poni]

as long as the smallest cable is protected by the fuse/MCB then its ok, you can go up and down cables sizes as many times you want,