Found cable behind socket disconnected.

[Nat6]

Can anyone help me. I removed a socket face this morning and found only one of the ring main cables connected. The live and neutral (red & black) of the other cable were taped up individually and tucked away in the metal box. Earths of both cables were connected to the socket.


Why has this been done? The house is a 3 bed about 15 years old. The socket in question is the closest (physically) to the fuse box. When looking in the fuse box both reds are connected to where they should be, protracted by a 32a mcb. This I understand is not safe. Although I believe it's been like this for some time.

Any suggestions for sorting it out?

Btw there is a separate mcb/rcdfor the garage which is connected via blanking plate in the dining room. I wondered if this has been done at some point and not original when the house was built.

 

[PrenticeBoyofDerry]

Why has this been done?

Would be very difficult to say without some investigative work.
Is the circuit actually a ring final and not a radial?

The socket in question is the closest (physically) to the fuse box. When looking in the fuse box both reds are connected to where they should be, protracted by a 32a mcb.

That does not confirm it as a RFC though, the only way would be to perform tests

This I understand is not safe.

It is unsafe if the RFC is not complete yes, but again this would need to be confirmed

Any suggestions for sorting it out?

Qualified electrician that is capable of inspection and testing!

Btw there is a separate mcb/rcdfor the garage which is connected via blanking plate in the dining room. I wondered if this has been done at some point and not original when the house was built.

Again impossible to say! But as blanking plate has been used, you can assume that it was not part of the original plan.

 

[Lectrician]

I would say there was a fault on one leg of the ring, and they have disconnect this leg (in two sockets) to stop the RCD/MCB tripping. The MCB should of been changed to a 20amp, or IDEALLY, the fault found/section of cable replaced.

 

[PrenticeBoyofDerry]

It could be that the RFC is fine and this socket is a spur with a disconnected spur to it, but this is all guessing and assumptions. Get the Megger/Fluke man to it!

 

[rjm2k]

If you have a multimeter you could check whether or not it's likely to be a broken ring by setting it to measure ohms and probing the live and disconnected live then the neutral and disconnected neutral. If either shows a reading then it would seem to be a broken ring.

Make sure you turn the power off first though!

 

[Nat6]

Thanks for your help so far. I've taken off the socket faces closest to the socket in question (5 in total) but all have been connected with 2 cables as a ring main should.
I have since found out that above this socket used to be a fused spur with an alarm system wired off it.
I guess it is possible that one of the ring cables was diconnected when the fused spur was added off it, but why? Is there any reason that a ring is broken to add a spur?

I think I will use multimeter to test for voltage on the taped up wires, this would prove that's it's still connected. If that's the case I wonder why it's been left like this? I will also test continuity between the lives and between the neutrals.

 

[rjm2k]

No,with power off test continuity between live and live plus neutral and neutral

 

[Nat6]

Ok so I tested continuity between the lives and the meter went to zero suggesting that they are connected. Continuity between the neutrals was also present. I carefully switched main breaker back on and tested the live which read 230v.

Does this mean that I can reconnect the cable? Are there any further tests can do to to see why it might have been left diconnected?

 

[rjm2k]

A reading of zero ohms would indicate no continuity but I assume you didn't calibrate the Meter and did see a change of reading when probing? Same kind of movement as touching the probes together.

 

[bernardgreen]

A reading of zero ohms would indicate no continuity

A reading of zero ohms would indicate super conductivity and therefore continuity

No continuity would produce an infinately high number of ohms on the meter.

 

[Nat6]

Ok cable connected nothing went bang nothing tripped. All appears ok. I've tried that socket plus many more with a load and everything's been ok so far. Thanks for all ur help, glad I stuck it out and didn't call a sparky straight away, saved ££