Wire termination sequence numbering

Agreed. Also good old 134.1.1 especially if the manufacturer's instruction say so. (Does nobody read them?)

Yes that bit is simple but you also need to move the existing neutral for that final circuit from the neutral bus bar to the load side neutral of the RCBO. 

It's identifying which wire is the correct neutral that is a pain when they are all jumbled and they enter the DB as singles from trunking.

Usually need to isolate the whole board since pulling off the wrong neutral would leave it floating to line voltage (and shut down what ever was running on that final).

I don't have the luxury to shut down these boards so have to signal inject onto the desired neutral and try and pick it up at the DB but with all the wires in trunking the cross talk makes this a bit hit and miss.


I know I have read an explicit requirement to wire N and CPCs to the corresponding numbered terminal on the bus bar but I haven't been able to find it again.

If I can point to a specific reg or GN that should have required the original installer to sequence the wiring properly then the client will send them the bill for the additional cost.

I see the problem. Try 514. I don't think that the sequence is important, but each circuit should be identifiable.

as a practical tip, if it is singles and there is a little slack and not too much risk of lieve metal to touch, you may be able to use a clamp meter to find the N with the equal and opposite current to the L.

Of course there is a slim chance of more than one final circuit having the same load current