Underground power cable depth

Morkin

Hi,

I was doing some gardening between my garden shed and hoiuse last evening and hit something bouncy with a pitch fork. I thought it was some timber so wne tto pull it out. it was a black cable which i had nicked. it turns out it is the electic feed to the shed.

The house is detached in an estate and I'm in just over 1 year. I paid a lot in overs to have the cable laid as I requested it after paths etc. had been poured.

The cable is 8mm armoured and thankfully has not been connected to the distrib box in the house yet but it's been left paralle to the side footpath and only about 2 inches under the soil.

My questions is what are the regulations for such cables and where in the building regs are they specified. I'd like to know before contacting the builder (still onsite) and complaining for what that's worth.

All input appreciated,

M.

smashey

At the very least, it should be in a pipe of some sort.

billy_beckham

To the best of my knowledge SWA can be buried as it is....no need for pipe. But it should be lower in the ground than 2"

Steve

ETCI 2005 edition says:


Cables in the ground shall be protected against impact and other mechanical damage by:
- suitable mechanical protection in accordance with 522.6.6.1 and
- installation at a depth in the ground in compliance with Table 52B.
Where there is a risk of impact or other mechanical damage or where future excavation or similar activity is likely,
additional measures shall be taken such as:
- supplementary mechanical protection consisting of tiles, concrete slabs or metallic covers; or
- installation at sufficient depth.
Suitable indication shall be provided above a buried cable at a distance of approximately 300mm vertically below
the completed surface or midway, whichever is the lesser.

Table 52B states:
The minimum depth for SWA in domestic gardens is 450mm
Non armoured cable must be laid in pipe at min. 300mm

Morkin

Thanks for all replies so far. Looks like the cable should be at least 1.5 feet underground. I'll rant at the builder for all that's worth.

M.

Kashkai

During construction work on my house, the builder was digging a trench from the ESB pole in my garden to the new meter box when he found that the power supply cables from this pole to my house and my neighbours were just 2 inches underground (no protective pipe either just bare cable). I scraped away the topsoil to see the black power cable running just under the surface to our houses. I informed my neighbour of this at the time but she forgot until last week when she was getting a new path put in and her builder dug through her cable.

Stoner

As advised above 450mm for SWA directly burried in soil in a Domestic Garden/paths and drives.

most people would put a cable smaller then 6.sq.mm SWA in a polythene pipe

watchingandwait

I understood that the previous requirement was 450mm but that this had been increased to 600mm. The cable should be laid on a sand base, with sand over the cable aswell, esb warning tape should be laid on top of this and the rest back filled with topsoil etc. I'm sure the esb website has guidelines on underground services ....

Steve

Just to clarify: this will not be in the building regs, the ETCI regs apply to all electrical work.

The 4th edition is due soon or may already be out - if there are any electricians still on-site they will know. 3rd edition definately states 450mm but this may have now increased.

The point is still that 2 inches below surface is not acceptable - It's obvious that this will at some point come into contact with a spade or garden fork.

As posted earlier - and IMO laying in conduit or heavy duty plastic pipe would be recommended.

If the cable is damaged, make sure the builder gets it replaced and not just taped up and re-buried deeper.

If you want leverage - threaten to call the ETCI or RECI and get an inspector out - they can cause big headaches for the electrician / builder who installed it.

Mr Magnolia

stevec wrote:

ETCI 2005 edition says:


Cables in the ground shall be protected against impact and other mechanical damage by:
- suitable mechanical protection in accordance with 522.6.6.1 and
- installation at a depth in the ground in compliance with Table 52B.
Where there is a risk of impact or other mechanical damage or where future excavation or similar activity is likely,
additional measures shall be taken such as:
- supplementary mechanical protection consisting of tiles, concrete slabs or metallic covers; or
- installation at sufficient depth.
Suitable indication shall be provided above a buried cable at a distance of approximately 300mm vertically below
the completed surface or midway, whichever is the lesser.

Table 52B states:
The minimum depth for SWA in domestic gardens is 450mm
Non armoured cable must be laid in pipe at min. 300mm

Is this available to read on-line Steve?

Steve

Mr Magnolia wrote:

Is this available to read on-line Steve?

Officially it's pay per view but try "www.etci.ie rules.pdf" in google.;)

Mr Magnolia

Thanks Steve

Stoner

stevec wrote:

Just to clarify: this will not be in the building regs, the ETCI regs apply to all electrical work.

The 4th edition is due soon or may already be out - if there are any electricians still on-site they will know. 3rd edition definately states 450mm but this may have now increased.
.

Yep I second this, I got our QA head to check it too, the new regs are not out yet, and I read 450mm from the current ones, please note this is not an ESB cable and is not subject to their requirements.

Also as stated before what you have is not correct, and all an electrician has to do is install to the current ETCI regs at the time of installation, in this case it would have been the 3rd edition and they were not followed, new regs are due towards the end of the year

*Edit* FYI new regs are in for a reprint ATM and caould be out within one month