Electric supply underground to house

[dizz]

Digging a trench, and discovered an electric supply coming into our Victorian house. The supply is about a foot under the ground level and was just in soil - it looks about 30mm diamater and initially I thought it was the roots of some ivy (it's got some sort of thick black sheath wrapped around it). There was a wall on top, which I am rebuilding, and am digging the trench for foundations, as there wasn't any before. I've had to dig around and under the cable to get the depth for the foundations. It's now in "mid-air" and enters the ground either side of the trench.

Readymix is on order to fill the trench, but how do I treat the cable - should I place some sort of plastic over it to identify it for the future and cover it in soil before piling in the ready mix, just pile in the ready mix, or box it in/put plastic pipe around it?

 

[PrenticeBoyofDerry]

Is the cable still live or redundant?
Ideally cable in a duct and bedded with stone cap/copings laid above and electrical warning tape run above that.

 

[dizz]

Not sure if it's live or dead, but it's heading towards our house, and the neighbour knocked out a similar cable neraby last year. OK, but definitely not pour the concrete mix straight in.

 

[PrenticeBoyofDerry]

No I would not pour concrete over cable, as you need to allow for ground movement offering the cable some flexibility, so to prevent stress on the cable. It needs to be protected from any tooling and marked for identification purposes, could well be your main supply to the property. It might be worth giving the DNO a call for confirmation but 30mm sounds a little on the small side, do you/neighbour have any outbuildings with an electrical supply?
If it is the main supply the DNO have responsibility for it and they may not take to kindly if you start messing with it.

 

[plugwash]

It could well be the cable supplying your house, they dont replace underground supply cables unless they have to.

You can buy split ducting which is designed to retrofit over existing cables, I would think that would be what to use in a scenario like this.

I would also put "caution electric cable burried below" tape about half way between the cable and the surface.

 

[securespark]

PICTURES!!!!!

 

[dizz]

These pics may not come out the right way around, cable runs horizontal obviously.

Untitled

• dizz
• 18 Sep 2012
• 1

Untitled

• dizz
• 18 Sep 2012
• 1

 

[securespark]

Thank you.

Yes, that looks like a DNO's supply cably to (or more rarely, from) your property.

How much of it have you exposed?

 

[dizz]

I have about 16 inches along its length exposed and have cleared earth below by about 2 inches.

 

[westie101]

Looks to be a 2c .0225 sq in Copper PILCSTA.

Just bed it in about 2 in of sand before concreting, but put a 32mm duct accessible from both sides next to it so if it ever needs replaced the concrete doesn't need removed!
If the trench/concrete is next to the house wall you need to consider taking the duct through the wall to aid replacement of the cable should it ever go faulty.

For that short a distance marker tape is not really required but there is nothing to stop you putting it on if you can get a short length.

Perhaps a warning, always ask the DNO before digging as if you have got an underground supply, you WILL have a buried cable in your garden that they should have a record of!

 

[kai]

Be very careful with that exposed cable, it may be fused at over 600amps at the substation, if it gets damaged there will be a massive explosion!