mixed ring circuits linked

[startout2007]

i have just looked at a strange house with loads of extensions done. the board isn't labbled up. on turing off the mcbs on two ring circuits its still live unless both are turned off. so i assume at some time a link has been bodged in between the two rings for some sockets. whats the best way to try to find the problem as the house is a right jumble.thanks

 

[Johno]

i would assume that the house was wired in 2 rings, but when connected into the mcbs they put 1 leg of 1 ring with the other and vice versa. i have come across this before

 

[uksel]

first thing is to do a continuity check on all of the cores of the two rings (you never know the rings could be inter-connected at the board due to a CU change or something).

if you have 3 or 4 line conductors from the 2 rings with cont. between then you've got a problem

it would be unsusual for a diy expert to connect to live sockets to each other, they just have a habit of sharing a supply to the place where they want it at the time

i would assume that the house was wired in 2 rings, but when connected into the mcbs they put 1 leg of 1 ring with the other and vice versa. i have come across this before

ooh beat me to it

 

[startout2007]

forgot to say i did a continuity cheack on the live conductors at the board and all interconnected

 

[Johno]

so you disconnected all cables from each circuit at board and tested for continuity?(not just lives)

 

[startout2007]

no i just disconnected all four live conductors from both rings and they all showed a connection between each other, continuity reading.

 

[uksel]

first thing i would do is go around all of the sockets and note which ones have more than 2 t+e connected. see what you're up against

 

[Johno]

disconnect neutrals aswell

 

[ian.settle1]

first thing i would do is go around all of the sockets and note which ones have more than 2 t+e connected. see what you're up against

Why???????????????

 

[uksel]

not sure really, it was late when i posted that (and i'd had a little drink)

but if he'd proved there is an interlink in the circuit somewhere, if you find 3 or more cables in a back box, it would be an immediate suspect for the interlink.

 

[Des 56]

Unless theres a section that looks suspect

Maybe concentrate on one leg at a time
Link out live and earth of that one leg and go round taking the readings as per a radial etc

It may give you an early indication of what rings were intended or original,perhaps having a beter start point for the slog

 

[startout2007]

thanks for your ideas that was the way i was thinking looks like the isnt a easy answer i will let you know when i tackle this in a weeks time.

 

[uksel]

where are you based startout?

 

[startout2007]

i live in northants

 

[garyinderby]

starting a job on monday the same sort of problem. got three line conductors into one old syle fuse feeding both upstairs and downstairs ring. also lighting circuit for whole house on one circuit. think me going to have fun. so going to get missus to shave me head tonight, stop me tearing it out tomorrow, lol