Having replaced a single socket with a double and added a second double in the same room by extending the ring, by chance I found that there was no continuity in what I assumed was a ring final circuit. Checked my connections and all were good.
Just in case I was looking at a spur on spur connection rather than a ring I did some checks from the consumer unit.
The consumer unit has an RCBO on each circuit and all “sockets” are on one RCBO rated at 32A with two 2.5mm T+E cables connected. I disconnected both the live connectors and the neutral connectors then did a continuity test L to L and N to N and there was no continuity. So do I have an open ring circuit or two radials (which shouldn’t be on a 32A RCBO).
All sockets are live when the cables are connected but if I remove one cable all kitchen sockets are live plus 2 in a bedroom. Swapping the cables over brings on the other sockets.
The other surprising thing was that when testing between L and N on one of the cables there was around a 9 ohm path. This is on the circuit feeding the kitchen so unplugged what I could with no effect. I have to assume that this is a piece of circuitry in something that presents a low resistance to a low voltage DC test voltage but not to AC mains (otherwise I would be looking at a standing circuit current of 26+ amps assuming 240V).
Does anyone have any idea what sort of device might exhibit this performance when tested with DC.
Once I can isolate the cause of this I plan to link L+N of each cable independently at the consumer unit then test the loop resistance at each outlet hoping that the socket with the highest reading is the nearest to the end/break. Having done that on one cable I will do the same on the other cable and see where that gets me.
I checked in a number of sockets to see if I could find any loose wires but no joy so far. A number only had a single cable connected though so it looks as if there are a number of spurs !!
This is in a 1980 house that my daughter purchased a few months ago and I wasn’t too happy with some of the wiring I saw and in fact found a socket without an earth and another with a L-N reversal. She did have an electrician come and check things out as I wasn’t happy that everything was on this one “ring” including the oven. However the guy said it wasn’t unusual and as she had raised the issue she was aware of not turning too many things on at once !
Sorry its such a long post but i wanted to cover as much as possible up front, any advise on how to tackle this issue would be much appreciated.
Thanks
Graham
Just in case I was looking at a spur on spur connection rather than a ring I did some checks from the consumer unit.
The consumer unit has an RCBO on each circuit and all “sockets” are on one RCBO rated at 32A with two 2.5mm T+E cables connected. I disconnected both the live connectors and the neutral connectors then did a continuity test L to L and N to N and there was no continuity. So do I have an open ring circuit or two radials (which shouldn’t be on a 32A RCBO).
All sockets are live when the cables are connected but if I remove one cable all kitchen sockets are live plus 2 in a bedroom. Swapping the cables over brings on the other sockets.
The other surprising thing was that when testing between L and N on one of the cables there was around a 9 ohm path. This is on the circuit feeding the kitchen so unplugged what I could with no effect. I have to assume that this is a piece of circuitry in something that presents a low resistance to a low voltage DC test voltage but not to AC mains (otherwise I would be looking at a standing circuit current of 26+ amps assuming 240V).
Does anyone have any idea what sort of device might exhibit this performance when tested with DC.
Once I can isolate the cause of this I plan to link L+N of each cable independently at the consumer unit then test the loop resistance at each outlet hoping that the socket with the highest reading is the nearest to the end/break. Having done that on one cable I will do the same on the other cable and see where that gets me.
I checked in a number of sockets to see if I could find any loose wires but no joy so far. A number only had a single cable connected though so it looks as if there are a number of spurs !!
This is in a 1980 house that my daughter purchased a few months ago and I wasn’t too happy with some of the wiring I saw and in fact found a socket without an earth and another with a L-N reversal. She did have an electrician come and check things out as I wasn’t happy that everything was on this one “ring” including the oven. However the guy said it wasn’t unusual and as she had raised the issue she was aware of not turning too many things on at once !
Sorry its such a long post but i wanted to cover as much as possible up front, any advise on how to tackle this issue would be much appreciated.
Thanks
Graham