no end to end reading for r1

[thebrownline]

Hi All,
Had a weird one this morning during an EICR.
Testing a ring final circuit in a 2 bed flat… kitchen was on a separate ring. With only the 32A MCB on, I identified 8 sockets on the circuit. Set up for dead testing… r1 end to end - open circuit.
rn - 0.35, r2 - 0.57.
Opened up the 8 sockets… no loose conections or signs of corrosion, however, the ring is wired in pre 2004 red & black… one socket in main bedroom has one leg black and red, the other is brown and blue. The other end of this brown and blue is nowhere to be seen.
With one leg of the ring in the MCB, all sockets have power… swap legs.. all have power.
Decided to try cross connect on r1r2 and got between a low of 0.23 and high of 0.27 for R1+R2.
There aren’t any blank plates, plastered patches from old sockets of jbs to be seen so I’m really confused as to what is going on as at the board I dont seem to have a ring but around the sockets I do.
Thanks in advance for any thoughts given.

 

[cliffed]

Seems peculiar r1 open circuit if the sockets are all ok no loose connections & cables are present, looks like a junction connection somewhere hidden

 

[HappyHippyDad]

Sounds like the brown and blue goes to a junction box or to another socket/FCU etc (that is hidden).
Or, you have a break in the actual line conductor, between sockets.
You'll need to split the ring and narrow down the fault to between 2 sockets. If the fault is between 2 sockets you'll need to have a good understanding of the actual ring layout, so that you can determine which 2 sockets it is between.
I would be making the client aware that this could take a while. Then, slowly and calmly work out the layout of the ring.

There are times when the MCB can be reduced to a 16A or 20A to at least make the situation safe. I wouldn't be doing that in this case as you have continuity with the neutrals meaning there is a line conductor floating around somewhere which could make contact with something.

 

[thebrownline]

Seems peculiar r1 open circuit if the sockets are all ok no loose connections & cables are present, looks like a junction connection somewhere hidden

Thanks for your reply.
Yes, thats what I’m thinking.

 

[thebrownline]

Sounds like the brown and blue goes to a junction box or to another socket/FCU etc (that is hidden).
Or, you have a break in the actual line conductor, between sockets.
You'll need to split the ring and narrow down the fault to between 2 sockets. If the fault is between 2 sockets you'll need to have a good understanding of the actual ring layout, so that you can determine which 2 sockets it is between.
I would be making the client aware that this could take a while. Then, slowly and calmly work out the layout of the ring.

There are times when the MCB can be reduced to a 16A or 20A to at least make the situation safe. I wouldn't be doing that in this case as you have continuity with the neutrals meaning there is a line conductor floating around somewhere which could make contact with something.

Thanks for your reply.
Its certainly going to take some time, especially when there are no visible patches of old jb’s or fcu’s.
I definitely dont want to split the ring into radials when there is a rogue line conductor lurking in the shadows.

 

[Pretty Mouth]

How are you testing for power at the sockets?

 

[thebrownline]

How are you testing for power at the sockets?

Just using a plug in tester. I had the faceplates off the wall to check for loose connections during dead testing but didnt power up again with them off.

 

[HappyHippyDad]

Just using a plug in tester. I had the faceplates off the wall to check for loose connections during dead testing but didnt power up again with them off.

Did you ever find the fault?
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