This is the inside view of the main CU in my house (there is a second 4 way CU not shown). The cables in the incomer are 16mm feed from the (isolatable) meter and feed to the second CU. The shroud at the top of the picture is the incoming SWA cable from the meter which is on the other side of the house (result of major extension and relocation of CU).
I am planning to do the following reconfiuration work and, when that's done, I intend to call in a sparks for a full PIR.
Circuit 2, on the non-RCD side as seen, is the radial circuit mentioned in this thread. I intend to move it to the RCD side of the board and, as you can see, I have crimped on some additional lengths of 2.5mm in preparation. The reason it is on the non-RCD side is because there is a freezer on the circuit and the sparks who installed the CU recommended it should be so. However, the circuit also feeds an external socket as well as two kitchen sockets close to the back door so it should be RCD protected on that account.
The 'anomalies' I note are:
Circuit 14 is: (i) a ring main serving basement games room, utility room and two power points in garage (each spurred off power point on the other side of the wall to the utility room); (ii) 2.5mm radial feed for power to the basement lobby (2 x 13A sockets) and a walk-in cupboard (1 x 13A socket); and (iii) feed to FCU for garage door lifter (not actually installed yet). The blue tape identifies the feeds for the radial and the garage door. Four conductors in one MCB seems a bit untidy so I'm thinking of moving the garage door feed to circuit 3, which is a 16A MCB presently supplying boilers, alarm and bell (all on individual FCUs). Alternatively, I could move the radial to circuit 3 which would give 16A protection for the cable but I would lose the RCD protection (not absolutely necessary as the sockects are not adjacent to any outside doors).
Circuit 8 (6A MCB lighting circuit) has two conductors. I haven't identified which conductor does what but the maximum combined load is less than the MCB rating so I don't think I need to be too concerned about it.
Circuit 3 (16A MCB) also has two conductors - one feeds a FCU for the boilers and the other feeds 2 x FCUs for the alarm and bell transformer.
My plan for the reconfiguration is to remove the conductors for circuit 2 (MCB, neutral bar and earth bar), remove the busbar and MCB, then slide over all the MCBs up to and including the RCD, moving the neutrals and earths along one at a time, then re-install the circuit 2 MCB as circuit 10.
Does all that seem the right way to go about it? And is there anything else I should be considering before (and for the purposes of) the PIR I intend to have carried out afterwards?