Garden Wiring Problem

Tropheus

Hi,

I've done a fair bit of electrical DIY over the years, but have run into a problem with some garden lighting.

We have a pond in the back garden and garden lighting (that's no longer used). I noticed that some of the cabling around the garden for the lighting was damaged so decided to disconnect it. It's switched in the house and never turned on, but wanted to disconnect it just in case.

There is one large junction box in the garden beside the pond with four large cables (about 3/4 inch diameter) going into it. It was an absolute spaghetti of interconnected wires. I know this powers the garden lights and pond.

I presumed one of the cables was an input and the other three were outputs to the lights. Also connected into this mix was the pump for the pond filter and an outdoor dual socket. These have been working fine.

Three of the cables had coloured wires - the usual brown, blue and yellow/green and a red cable. Not sure what the red is for. The fourth cable had 5 white wires and an coloured earth.

I had obviously disconnected the power when unravelling the cables and then put the power back on to find the live. None of the three cables with the coloured wiring were live.

It turned out the one of the white wires on the fourth cable was live. I then used the continuity on my multi-meter to test the other wires. Three of the white wires gave continuity with the earth and each other. Can I assume that these are all earths? There was another white wire that I couldn't get a reading off at all. I thought it might be a neutral and connected it up, but it doesn't work.

After much testing, I found that one of the blue wires on one of the other cables seems to be a working neutral and is giving me a reading on the multi-meter along with the live white wire. The problem is, this cable with the working neutral is too far away from the new junction box I fitted so not easy to use.

I've also found that the four white wires that have continuity also give a voltage reading with the live. I presume this is normal if they are earths?

Is it possible that one of the white wires I'm getting continuity with is a neutral. It seems odd to have a live and earth on a cable and not a neutral.

To add complexity, the lights went through a switch in the house. I've tried the switches and there is definitely no other live wire bar the one white one.

Can an earth and neutral give continuity?

Any help would be much appreciated. Everything is disconnected for the moment until this is sorted and I have the pond pump running on a different circuit.

2011

Most domestic installations are neutralized. This means that the earth is very deliberately connected to the neutral which would explain the continuity reading.

Additionally the live conductor is connected to the neutral through certain devices. Example: A ordinary filiment bulb, the neutral connects to the live through the filament itself. Obviously this is a high resistance connection which limits the current through the bulb but throughout an installation there could be multiple bulbs connected in parallel reducing the overall resistance of the neutral / live connection.

Tropheus

Just did a bit of reading and see that neutral and earth are normally connected at the main box so that would explain the continuity. So therefore, I potentially have one live, three neutrals (possibility looped?) and one earth (which is coloured).