Radial off Ringmain Query

[oldbutnotdead]

Mapping is tedious but easy, all you need is a multimeter, a long single cable will save some walking but isn't essential. Sounds as if whoever built your extension took some shortcuts with the wiring.

 

[Aloo6]

Hi All,

Update on this - Resolved the main issue.

I replaced the socket and repaired the cable by trimming it. This did not do anything other than the reassurance that the old socket was replaced with something newer. While I did this I safely excluded the supply to the extension and turned the power back on, this resulted in the extension being dead, so it is a long radial from the fridge socket.

I then started to trace what I thought was the feed to the fridge socket and the extension. I had assumed it was a kitchen socket the other side of the larder unit, but it wasn't. Both the fridge socket and the socket on the other side of the larder are supplied on separate cables which I followed all the way towards the other end of the kitchen (about 4meters). it looks like both were spurs before the extension was built and the extension builder turned the fridge spur into a radial.

I then focused my search back to the fridge socket and followed the cable and found a massive ball of electrical tape behind the tiles, removed the tile and I reckon at some point someone nicked a cable and did a repair using a choc-block. Managed to have a look and there was another damaged live and completely broken earth next to it. Repaired this and tested and the problems are solved. there is no ghost voltage and the extension now shows healthy (on a basic socket tester) and can trip the RCD.

Im going to either put a wagobox in there or put a backbox with blanking plate.

What I don't understand is why the socket tester showed a Live/Earth Reverse, Missing ground. I thought it would have showed an open ground, or did the ghost voltage/damaged live have parts to play aswell?

I am going to keep tracing the cables and try to map it out where both these 2 supplies come from, just out of interest.

Thanks for the advice and guidance thus far.

 

[securespark]

I've had a combination of lights on a socket tester that was not in the manufacturers instructions!

 

[flameport]

What I don't understand is why the socket tester showed a Live/Earth Reverse, Missing ground.

Those devices are ultra basic, and will show totally misleading results for plenty of faults.
They are best used as 'working / not working' rather than any kind of indication as to what the problem actually is.

 

[ericmark]

Update on this - Resolved the main issue.

Thank you, interesting to hear what was found. I will admit I often wonder what is in some testers, would be interesting to reverse engineer one, maybe send one to Big Clive?

I do use testers other electricians seem to frown on. I still use my non contact tester I love being able to see if there is a line supply without relying on the neutral and/or earth being sound, hard wire testing needs two intact wires, the ---- shown shows line, also a buzzer, however I see electrician and electrician saying these testers should be thrown in the bin, same with neon screwdrivers, however although the clamp on the meter shown can show when there is current flowing, it is still doing it with no contact, so the neon screwdriver is good for identifying borrowed neutrals.

But although I know the meter measures DC current using the hall effect, I don't really understand what the hall effect is? So may as well say it uses magic.

The main thing is these testers show there is a fault, yes it shows 1.7Ω when pass mark is below 1.4Ω but at least it does show when there is a major fault. But as to what the fault is, often it needs more testing.