Re-routing a ring mains

[davelx]

From off, a neon is initially non-conducting below the strike voltage. Once struck, the voltage across it drops to about 30% of the striking voltage. A series resistor limits the current and drops the rest of the voltage.

 

[SUNRAY]

I should mention that if the CU main switch and all MCB are switched off and you test for continuity between sockets on different circuits they will appear to be open circuit between L's and I think I've seen that test in there somewhere. It may not be, but your long post felt a little confusing.

Can I have some clarification on this please. If we take any Ring circuit, switch it off at the MCB, whip off a socket and have the cables hanging in the air. What would lead to there being continuity across L and N on the same cable?

My comment is based around testing between sockets on different circuits...
with everything in the CU switched off, ring1 L will not be connected to ring2 L but ring1 N will be conected to ring2 N as will 1E to 2E And I think I saw that as one of your test results.

 

[securespark]

Presumably, my socket tester would identify this when testing on the energised circuit?

No, I don't think so.

 

[SUNRAY]

I should mention that if the CU main switch and all MCB are switched off and you test for continuity between sockets on different circuits they will appear to be open circuit between L's and I think I've seen that test in there somewhere. It may not be, but your long post felt a little confusing.

Can I have some clarification on this please. If we take any Ring circuit, switch it off at the MCB, whip off a socket and have the cables hanging in the air. What would lead to there being continuity across L and N on the same cable?

My comment is based around testing between sockets on different circuits...
with everything in the CU switched off, ring1 L will not be connected to ring2 L but ring1 N will be conected to ring2 N as will 1E to 2E And I think I saw that as one of your test results.

 

[Jupiter01]

No, I don't think so.

I thought a socket tester would pick up a missing neutral on a socket?

 

[Jupiter01]

From off, a neon is initially non-conducting below the strike voltage. Once struck, the voltage across it drops to about 30% of the striking voltage. A series resistor limits the current and drops the rest of the voltage.

Are you talking about the neon light on an FCU?

 

[securespark]

I thought a socket tester would pick up a missing neutral on a socket?

In the example I talked about, there was still a neutral present at and connected to the socket from the other leg.

 

[davelx]

Are you talking about the neon light on an FCU?

Applies to any neon indicator light, though the same principle applies to neon display signs etc, though they use an inductive ballast to limit the current rather than a resistor.

 

[Jupiter01]

The clearest troubleshooting of discontinuity in wires seems to be by unwiring the entire ring and then check from point-to-point. This will eliminate the risk of checking at one socket and what you suspect is the other end of this same cable at another socket. Whilst you may get continuity across L and N (joined together on the same cable) this may be because there is an intermediary socket.

Would you agree with that approach?

 

[SUNRAY]

4 pages, 19 days, 21 posts from OP, 33 replies.


And we still don't know what it is you are asking or what the fault is, or what the circuit is, or how many sockets...

 

[Jupiter01]

4 pages, 19 days, 21 posts from OP, 33 replies.


And we still don't know what it is you are asking or what the fault is, or what the circuit is, or how many sockets...

I’ve given up explaining my situation as you suggested that it requires attention from an electrician.
I was asking some generic questions to help me understand some of the issues I was experiencing but without delving into the specifics of my situation

 

[Jupiter01]

The clearest troubleshooting of discontinuity in wires seems to be by unwiring the entire ring and then check from point-to-point. This will eliminate the risk of checking at one socket and what you suspect is the other end of this same cable at another socket. Whilst you may get continuity across L and N (joined together on the same cable) this may be because there is an intermediary socket.

Would you agree with that approach?

Are there any fundamental disagreements with the understanding I have set out here? Thanks again.

 

[Harry Bloomfield]

Not sure what a neon would do when below strike voltage.

Below strike voltage, it would be high impedance/ no continuity through it.

 

[Harry Bloomfield]

and switched on if it's a switched FCU?

If turned on it might show continuity, but that would depend upon the type of load on the FCU.

Are there any fundamental disagreements with the understanding I have set out here? Thanks again.

If you can be absolutely certain you have disconnected each end of every cable, that would be the way to tackle it. It all comes unstuck, if there are any hidden sockets, joints, or etc..

I agree with Sunray - you have given this your best shot. Diagnosing it needs someone experienced to tackle it and your lack of experience and understanding is obvious from your posts.