Extending underground cables

Think laterally - put another light where the cable ends and use that as the joiner

Hopefully the cable is SWA (ie. armoured cable)?

If it isn't SWA it ought to be redone anyway.

I think you know the answer is "No".

If it is SWA, you can use the 2-way versions of these

Need to know what type of cable.

Yes.

No.

Yes.

Is it mains? If so it isn't.

If its 12V then a couple of cheap crimps and some shrink wrap would be OK.

If its mains, buy a water proof connector or junction box or a joint kit like

You do not say if this is mains or low voltage (i.e. 12V). That might make a difference to people's perception of the issues.

On Thu, 27 Nov 2008 09:41:40 +0000 someone who may be Dan Smithers wrote this:-

Replacing it, or fitting a new light in a new place and removing the old one?

Too short to go into the new fitting by a few cm? Can you get a bit more out of the ground?

What sort of cable, what depth, what protection, what voltage?

Probably, though it depends on the type of cable.

Removing the old one and replacing it with a different one in the same position. The contacts for the new one are not in the same place as the old ones.

Correct.

I'm trying to get the information before I tackle the base at the weekend. With any luck I will be able to get a bit more out of the ground, but if I can't...

Three core cable, mains voltage. The end I can see appears to have a casing that finishes a few inches before the end of the outer insulation.

I shall probably go and visit the local Screwfix for their connector. Unfortunately the local electrical factor has closed so buying the extra half meter of SWA cable is going to be a bit awkward.

Now we know a few more important details. How long is a "few cm"?

If the cable is long enough to fully and properly(*) enter the enclosure with the terminals but the wires won't quite reach the terminals your suggested choc block and tape will do, suitably rated extension wires and choc block of course. Crimps would be better but to do those properly you need a rachet crimper not a simple pliers jobbie.

(*) SWA should terminate in a proper gland on the enclosure to keep water of the cable and enclosure. IIRC the armouring should also be connected to the CPC.

insulation.

connector.

TLC sell SWA by the meter and deliver for free

AWEM

Only if the join is inside the new fitting. i.e. you can extend the wires in the cable to make them reach new terminal positions so long as the cable itself and its outer sheath still get into the fitting.

There are - see the TLC links.

You can identify exactly what type of cable you have by looking here:

The answer will dictate what method you can use to make a joint outside or underground if you need to.

thanks.

I've also spotted that I'm not too far from their Coulsden branch.

I think that an extra meter of cable, a short length of flexible ducting so the cable can be accessed without breaking the concrete base that I'm proposing and a resin-filled connector will be the way to go. Too late for this weekend though.

I expect that 1.5mm 3-core will be more than enough for a light.

Dan Smithers formulated the question :

That depends upon the cable type. The standard method for an underground armoured cable joint would be a special joint made by the likes of 3m. It is basically connectors and a clamp + link for the earthing armour. In the kit is a box shape for a mold. Once jointed and encased, you pour a two part resin compound into the mold, which then makes the whole thing waterproof and solid. The resin is fairly similar to Araldite.

Absolutely not!

See above.

You probably only need two core - you use the armour as an earth.

The TLC guys at Coulsdon are very helpfull.

Peter

On Thu, 27 Nov 2008 12:08:01 +0000 someone who may be Dan Smithers wrote this:-

Can you not mount it a few cm lower?