Wiring garden street lamp

[Anna Rack]

Moved to a house a while ago which had a street lamp in the front garden. It was removed to make way for a fence and I now want to reinstall it about 3m from the garage where it will be connected via the lighting circuit. The old wiring was just normal 3 core cable buried just under the soil in plastic pipe, hardly ideal!

I've no problem burying some mains armoured cable but thought I might use some 12v bulbs and have a transformer in the garage which would be safer. The question is what would be the best way to bury the cable, bearing in mind there would be no danger of electric shock, would in a hose pipe or similar be acceptable?

 

[Marvo]

If you're using Steel Wire Armoured (SWA) cable you can just dig a trench maybe 500mm deep and put a couple of inches of sand in the bottom and lay the cable straight in there.

Whether you use 230 volt lamps or 12 volt lamps makes little difference if it's just one fitting and a fairly short cable run. If there's multiple fittings and longer cables involved then the higher current of the 12 volt lamps make mean you need larger cables.

 

[Anna Rack]

Thanks for the reply.
I was thinking if I used a low voltage supply I could do away with the need for armoured cable and just use appropriate twin core cable buried in a hose, is this acceptable?

 

[SirKit Breaker]

Thanks for the reply.
I was thinking if I used a low voltage supply I could do away with the need for armoured cable and just use appropriate twin core cable buried in a hose, is this acceptable?

The hose will fill with water no matter how well you seal it up, and this will degrade the cable fairly quickly. Do what Marvo has suggested and it will last for years. Armoured cable is not that much more expensive than twin and earth, especially as you only need a short length. Any electrical wholesaler will cut it to length for you. But get an extra meter or so.

Cheers.........Howard

 

[Anna Rack]

OK thanks for the replies, will go for the 1.5mm swa.

 

[Marvo]

Hose pipe isn't going to provide protection against damage by animals or someone with a spade and TBH it's acowboy method that will usually come back to bite you. SWA cable is a much more elegant solution and as Howard already said I doubt the cost difference is significant. Don't forget the glands, shrouds and earth rings to go with it. Dig the trench first so you can measure the length including deviations and I'd usually allow an extra meter at each end for fitting the gland, connecting up and making pretty.

 

[Engineer54]

You'll be best served by getting an electrician to make the glanded end terminations, as i've yet to see a novice come even close to making them off correctly!!

 

[Anna Rack]

I've used swa a few times in the past and as you say it can be quite hard terminating the ends. That was part of the reason to do not use it, also 12v would only require 2 cores. But using the swa would also mean it could revert back to mains voltage in the future.

 

[telectrix]

and be sure to get the correct glands. if in doubt, it's only an hour's work for a spark to terminate.

 

[Marvo]

Probably not a bad idea, if you do the donkey work like drill any holes and bury the cable etc just get a sparky in to fit glands, connect up and test.