routing underground cables.

[edwinchester]

Hi,

I am currently digging a 600mm trench to lay mains electrics from my house to the new garage which requires buiding regs sign off. My question is what to do when I have to cross the sewage pipes in the drive do I have to go under the existing drainage or can I bring the cable over the top of the drains which will give me less than 600mm depth?

Any advice much appreciated

 

[Steve]

Whichever you feel comfortable with. Though I'm not sure if theres any specific reg about this. Someone else will be along to answer shortly.

 

[JACKC]

There is no reg for depth of burying SWA, it is a judgement call of the person doing the work. If the area is liable to be dug up ie for planting plants etc then the deeper the better. If going across an area that will be left untouched or under a patio then I usually dig to 400mm and place warning tape at 300mm. As it will be notifiiable work you can show the trench to the sparky signing off the work or as you are notifying BC yourself ask them if they want to see it before burying. I would also describe route of buried cable on the electrical installation certificate.
Hope this helps.

 

[edwinchester]

Thanks guys I'll go for over in that case to save on the digging!

 

[Click-Sure]

I've always gone 18 inches down, with marker tape about 8 inches above that, if acheiving this depth means going under another service, then so-be-it.

 

[Lectrician]

The general rule is 600mm for HV and 450mm for LV. This is not set in stone.

 

[ColJack]

0.6m is mentioned as minimum for caravan sites, so I recon that it's good for general burried cables too..