Cable buried in a flower bed

[Pretty Mouth]

Had a look at a job a few days ago where, should the work go ahead, it would be necessary to run a cable under a flower bed. This is the only option acceptable to the customer unfortunately. The cable will be low voltage, ELV is not an option as the cable will supply power to sockets.

The flower bed is raised by about a foot, is narrow, and lies between a path and a fence. I suspect the concrete holding the fence posts will prevent me burying the cable to a decent depth.

Has anyone got any clever ways of protecting such a cable from damage when the flower beds get dug over?

 

[nicebutdim]

I had considered this, perhaps using black pipe with electrical warning tape wrapped around it. Have seen this done a couple of times on farm instalations, and it seemed to work well, it is very tough. Kinda breaks a reg or 2 though doesn't it?

How about flexible ducting wrapped with tape? Still fairly tough and no regs contravened.

 

[Dustydazzler]

Just saw this on the news

Man electrocuted after drilling through mains cable under garden

A Swindon man was airlifted to hospital after drilling through a mains electricity cable while carrying out DIY in his front garden.

uk.yahoo.com

 

[pc1966]

I'm surprised that manufacturers are suggesting galv conduit for direct burial in soil. I would've thought it would rust through eventually?

I would expect so. You can get stainless but at a price:

20mm Stainless Steel Conduit 3mts - 304 Grade

Based in Northern Ireland, Dungannon Electrical Wholesale is a family run business providing electrical goods and equipment to both Trades and the Public.

www.dungannonelectrical.co.uk

 

[swaRRR]

My first thought was plastic conduit but obv a spade can break through this. Then i thought that cheap ali pipe you can get from DIY shops but then it'd need earthing.

Personally i'd just run it in a piece of metal conduit with a through-box for access and fly lead it on the inside for the earth.

 

[swaRRR]

Just saw this on the news

Man electrocuted after drilling through mains cable under garden

A Swindon man was airlifted to hospital after drilling through a mains electricity cable while carrying out DIY in his front garden.

uk.yahoo.com

Isn't electrocution where it kills you?

 

[Pretty Mouth]

Thanks again all, this gives me a few ideas to work with.

I attacked a piece of rigid plastic conduit with a spade to see how it fared. It did better than I expected, and took a few good whacks before I was able to break into it.

 

[Intoelectrics]

Thanks for the comments guys, it's a great help.

The customer doesn't want the cable clipped to the fence unfortunately. She is quite particular about minimising visible cables. I'll not know until I start digging, but looking at it, I'm not at all confident I'll be able to get deep enough to avoid contact from spades when digging.

On a similar job I was able to run the cable in conduit, then bed a course of bricks of bricks on top. It worked well because there was brickwork immediately below the conduit too (it was a brick built raised bed), so was totally solid. I'm not sure that would work as well in this instance, as much of the run will probably be soil beneath. Perhaps that doesn't matter though.

I think any additional mechanical protection you add will help, ideally something that won't easily dislodge if struck by a spade.

 

[DPG]

Thanks again all, this gives me a few ideas to work with.

I attacked a piece of rigid plastic conduit with a spade to see how it fared. It did better than I expected, and took a few good whacks before I was able to break into it.

I suppose a lot will depend on the quality of the conduit and the outside temperature. I agree though, some plastic tubing is remarkably tough.

 

[Dustydazzler]

PVC conduit is pretty tough , you really have to give it a good whack with a hammer to crack it

many many years ago we got some pvc conduit from a wholesalers and it was described as unbreakable , naturally i put this to the test and yep even after about 15-20 whacks with a club hammer it wouldn't crack. think it was clipsal brand

 

[i=p/u]

Armoured burried in soil is good enough, plastic over the top is even better, its dogs dangles if you have black and yellow marker tape to top off. after that tell them you need digger.

 

[nicebutdim]

I suppose a lot will depend on the quality of the conduit and the outside temperature. I agree though, some plastic tubing is remarkably tough.

Was going to suggest putting the job off for a year to allow for testing in a range of weather conditions and temperatures.

Disappointed to see you'd already gone there