Hello,
I am trying to work out what order the sockets are connected in on the ring circuit in my house. I have been trying to do this by connecting the line and earth pins on a 13A plug together, plugging it into a socket (with the circuit breaker open naturally!) and then measuring the resistance between earth and line at each of the other sockets. The higher the resistance, the further away round the ring, right?
But I've run into a puzzle. There are two adjacent sockets in my kitchen. If I short one of them, and measure the resistance at the other, I get 0 milliohms. However, if I short a socket on the other side of the ring, and measure the resistance at one of the adjacent sockets, and then at the other, I get 470 milliohms at one and 380 at the other. Doesn't seem to make sense!
I have disconnected nearly all equipment from the circuit (there are a couple of sockets with built in USB chargers which I haven't disconnected, but the resistance between line and earth with no shorts is >200 ohms, so I don't think they're significant). I would suspect that there was something wrong with my tester, but the readings are reliably reproducible - if you blindfolded me and told me the reading on the tester, I could tell you which socket it was plugged into. I don't see how this is possible when there's no resistance between the two sockets. Any ideas?
Thanks
Jack
I am trying to work out what order the sockets are connected in on the ring circuit in my house. I have been trying to do this by connecting the line and earth pins on a 13A plug together, plugging it into a socket (with the circuit breaker open naturally!) and then measuring the resistance between earth and line at each of the other sockets. The higher the resistance, the further away round the ring, right?
But I've run into a puzzle. There are two adjacent sockets in my kitchen. If I short one of them, and measure the resistance at the other, I get 0 milliohms. However, if I short a socket on the other side of the ring, and measure the resistance at one of the adjacent sockets, and then at the other, I get 470 milliohms at one and 380 at the other. Doesn't seem to make sense!
I have disconnected nearly all equipment from the circuit (there are a couple of sockets with built in USB chargers which I haven't disconnected, but the resistance between line and earth with no shorts is >200 ohms, so I don't think they're significant). I would suspect that there was something wrong with my tester, but the readings are reliably reproducible - if you blindfolded me and told me the reading on the tester, I could tell you which socket it was plugged into. I don't see how this is possible when there's no resistance between the two sockets. Any ideas?
Thanks
Jack