Thread: Non-Contact 12V AC detector and broken backyard lighting system?

Depending on the type of insulation these detectors just make a few mm.
If the cable is old there is good chance that it is corroded black, if so you wont get any contact and therefor no light.
Only with clean copper it works

Originally Posted by arran

Hi all,

I have a pool light that is not working, it is 12VAC. There is voltage at the transformer but no voltage at the light.

The cable was run by the previous owner of the house so I'm not exactly sure where it goes underground. I am fairly sure that for the most part it is very close (say 50mm) from the surface.

Can I use a non contact AC detector at a distance of 50mm? Ideally I would like to see where the break is and dig in that spot.

Thanks in advance,
Arran

Listen and listen well, if as you describe, there is no point in self flagellation. What distance is involved ?
Depending on the topography, I suggest 500mm as a minimum depth.
Whose to say there is not more than one break.
At the very least, consider all other best practices for underground cabling.

Just hire a cable detector, Feed the tone in at one end and stop when it stops.

Baz

Hmmm, for a garden light on 12V with unknown age and unknown status of the cable I would simply get a roll of proper cable and replace the lot

Youre right, cheaper than hiring a detector too ..

one would think that it is in a pipe so i would disconnect the power remove the light and pull through some new cable

If it is done like in the place I rent now there is no chance to fix the cable anyway.
Here they used the crap cable from Bunnings what they sell for their garden lights.
Being flat and not round it is impossible to get a seal on the lamps without silicone or similar.
The copper itself is of cheap quality and starts to corrode after a few weeks outside to just black with insulation around.
The insulation goes hard and brittle in the soil and cracks cause water to get in - more corrosion until the resistance is too high to poser the 12V lamps.
I took a lengh of about 10m out and the insulation just crumbled into pieces...
Using this crap cable in a pipe would not make much difference unless the pipe segments are glued and the end sealed so there will never be any water in them.
Asked the landlord we would cover for the material costs if I fix the outdoor light systems and he agreed.
So lucky me got a quote first for the cable and lights.
Cheap lights from Bunnings and good underground cable from a proper electrical sypply store.
After seeing the price for the cable he agreed that it is enough to remove the broken lights and to leave the garden withouth lights.....
Mind you the total cost was 80 bucks for the lights and 300 for the cable, switches and two light sensors quoted from the supply store.
So no labour costs no surprises but still too much to pay
Makes me wonder if he really fixes the pipes for ducted system before the next winter...

Originally Posted by diavalo13666

one would think that it is in a pipe so i would disconnect the power remove the light and pull through some new cable

I would think that as well, however experience tells me not to assume, I've had "professional installers"(???) who wanted to run underground cable without pipe, lucky I had the pipe & made them use it.