On 27/05/2019 12:13, ARW wrote:
On 27/05/2019 09:47, Tricky Dicky wrote:
Apologies for resurecting this thread, but one final question. If I
cannot have RCBOs at both ends of the garage supply, if I go for RCBOs
in the garage CU and stick with am MCB in the main CU, does that MCB
need to be outside of any RCD protected group or can it be RCD
protected. There is a possibility that my garage supply cable can be
re-routed under the floor and within cupboards or voids where none of
it would require burial in a wall rather than the original plan which
was to take it through the loft where at least 2m would have to be
buried in a wall. I will not know how easy this will be until I lift a
few boards and see.

The MCB should have NO RCD protection. Only the garage end should be RCD
protected.

Did you know that if you bury the cable more than 5cm from the finished
surface on the 2m run then it would not need RCD protection?



Or mechanical protection applied. steel conduit should require no extra
protection.