Fault finding ring final RCBO

[Conteh]

Done a condition report on a old mains board, everything good apart from ring final, got 0.55 nn 33.7ll and 3.8 on ee, changed board to main switch and rcbos, carried out a full accessory swap on all sockets and fuse spares in house, found some bad practice, twisted lives, n and earth's, no sleeving all things to add to the high resistance problem. Retested board end to end 0.55nn 0.90 ee open ll. So changed the 32 rcbo to 2x16a rcbos broke the ring in half having 5 sockets on one side and 6 on the other. Rcbo trips! Any idea what I'm doing wrong?

I know the information isn't details but fire away with questions.

Help ?

 

[James]

I think you first need to confirm exactly what is connected to what.
Draw the circuit out and it may well become apparent

 

[Conteh]

I think that's what I need to do. Disconnect at mains board and individually Bell out what's what. I'm back there Monday. I will update whatever the outcome.

??

 

[pc1966]

Most likely there is some link between what you think are now two separate radials, and probably one RCBO is tripping faster than the other.

But hopefully if you can go back and do a more thorough check of the extent of L & N on each circuit you will find the problem. Also worth verifying there is proper isolation of L & N to all other circuits and to CPC/Earth.

 

[Conteh]

Thanks for all the help guys, outcome was that the ring had a dead short N-E from the lounge to the kitchen.
I took all the sockets off and disconnected all connections at the board, identified and mapped the wiring by way of continuity. I then was left with two unidentified cables between two sockets. I done a IR on this leg and had a connection between N&E. Left this leg disconnected. Reconnected all other sockets splitting the ring into two radials. Unfortunately the client lost a socket rom 1 side of the radial but i managed to get a full test. ?? Thanks for the advice and help.