End to End problem with Line wire

[ngoodson1969]

Hi,

I have a problem with a power ring main circuit. I have 'end to end' readings for Neutral and CPC but an open circuit reading for the Line. However, when I crossover Line and CPC and take readings at all the sockets, the readings are fine. I don't understand, if there is a disconnect somewhere in the Line then that should affect the readings when I do the crossover. Any ideas? Thanks.

Nick

 

[xraytek]

When you cross connect the wires it is the equivalent of creating a ring and placing your test probes at opposite ends.

The readings should always be about the same for sockets on the ring, because as one probe switches point the other moves to the exact opposite end i.e. when when probe is at 12 o clock, the other is at 6 o clock if that makes sense

If the ring has a break then there will be only one circuit path between each test probe, that will consist of some earth conductor and some line conductor. As the probes move round the proportion of earth and line conductor will change, but may only result in a slight change in readings.

Think thats right anyway

 

[flukey]

if you havent got end to end continuity why have you moved on to crossovers

rectify the end to end problem before moving on

 

[zupos40]

Hi,

I have a problem with a power ring main circuit. I have 'end to end' readings for Neutral and CPC but an open circuit reading for the Line. However, when I crossover Line and CPC and take readings at all the sockets, the readings are fine. I don't understand, if there is a disconnect somewhere in the Line then that should affect the readings when I do the crossover. Any ideas? Thanks.

Nick

What were the measured value for the end to end reading for neutral and CPC, and what were the reading at each socket when you crossed over Line and CPC.

Did you find the break in the Line

 

[ngoodson1969]

The end to end readings were Neutral 0.27 and CPC 0.35, the crossover readings at each socket were approx 0.3, give or take 0.1.
I removed every single socket face on the circuit and checked the Line connections but found nothing amiss. Not sure what else to try. I don't want to leave the circuit as it is.
Flukey, I moved on to the crossovers to see if that would help me work out the issue, didn't help, so trying to find out here.

 

[zupos40]

The end to end readings were Neutral 0.27 and CPC 0.35, the crossover readings at each socket were approx 0.3, give or take 0.1.
I removed every single socket face on the circuit and checked the Line connections but found nothing amiss. Not sure what else to try. I don't want to leave the circuit as it is.
Flukey, I moved on to the crossovers to see if that would help me work out the issue, didn't help, so trying to find out here.

Before try the following test to find the broken Line I would do an insulation test between live conductors and earth, in case insulation has been damaged to earth

As the Neutral and CPC were ok use ever of these rings, goto the CCU and take either the CPC or neutrals from there terminal I would take the neutral out and connect one of the broken Line conductors to the neutral, then test between L-N at each outlet until you fail to get a reading, mark that socket, return to the CCU and remove the line, then connect the other line to the neutral and test the other socket outlet, until you do not get a reading, I suspect that the break may be between 2 socket, there could be a JB under the floor, I had nails blow open the Line, had a similar problem in May this year, client had put a shelf up in the kitchen and damaged the Line.

Let us know how you get on.

 

[flukey]

The end to end readings were Neutral 0.27 and CPC 0.35, the crossover readings at each socket were approx 0.3, give or take 0.1.
I removed every single socket face on the circuit and checked the Line connections but found nothing amiss. Not sure what else to try. I don't want to leave the circuit as it is.
Flukey, I moved on to the crossovers to see if that would help me work out the issue, didn't help, so trying to find out here.

have you tried breaking down the ring and testing each way if you got no continuity you gotta find that break