On 14/12/12 21:23, A.Lee wrote:

Nearly all 'traditional' CUs are very tight for space when you use
RCBOs, so it will cost them a lot to design and build a new range, but
I can see in 5 years time that no-one will be installing dual RCD and
MCB CUs.

Once we do shift to all RCBO's - there would seem to be an opportunity
to revise the busbars in CU's as well.

The supply-side L is busbar - why not do the same with supply-side N ?

It would require only a fairly small change to RCBO's (drop the
input-side N flying wire, replace it with a terminal), though
main-switches would have to be modded to support this.

Current RCBO's with both L and N in the load wiring going directly into
the RCBO is very nice from a cable routing POV.