Discrimination

[nrg]

Hi All

a customer is wanting a ring in their garage (They can't explain why a radial won't suffice) so I

 

[ianmacd]

Do the calcs on the run from the house cu to garage cu and see if you can replace that with a 40A. If not then maybe only go to 20A in the garage CU otherwise, as you have said, it will not allow for discrimination. Other option is to leave the ring on the 16A breaker unless they want it upgrading becasue they keep tripping the 16A one?

 

[batty]

I would just leave house MCB as is and change Garage to 32 amp the worst that could happen one will trip but very unlikely on a garage circuit.

 

[ian932]

Main House CU feeding garage from 32amp MCB (non RCD Side)

6mm T/E to external box, where it is connected to 6mm SWA and run underground. Earth Terminated and not carried through to the garage.

Is the 6mm T&E run surface all the way?