How deep for main incomer?

[cardinal]

Evening all..

A friend of a friend has had a very lucky escape. Whilst attempting to put up a new fence, he smashed a fence post straight through his main incomer apparently. He says it was no more than 200mm in the ground, and to add insult to a very near serious injury or worse, they have sent him a bill for nearly £900 for the repair!

Anyone know of any reg's or guidelines on minimum depths? I have told him to seek legal advice before doing anything else, but was just interested. Good job it werent a metal shovel or something eh!

 

[bugsy]

I think it's 18 inches in old money but check with the DNO

 

[Engineer54]

All cable trench work, has been 600mm for as long as i can remember....

 

[ian]

Don’t think there is any specific depth in 7671, but most people seem to work on 600mm. The important thing is that it should not be damaged by using a spade etc.

However a old DNO mate told me that they had to work to

LV
Footpaths/Driveways, etc 450mm
Across Roads--------------600mm
Along Roads---------------600mm
Agricultural----------------910mm </SPAN></SPAN>

Not sure if that’s the case tho.

 

[Engineer54]

At 910mm the cable would need de-rating ....

 

[rocker]

The DNO don't have to work to BS:7671.

 

[Engineer54]

Who has quoted BS:7671.??? 600mm is the nominal trench depth for cable laying. Normally the cable manufacturers will also quote this depth, when stating current ratings of cables for direct burial....

I've used this depth for so long now, that if it is in the BRB, ....I've never noticed it ...lol!!

 

[cardinal]

Thanks for the replies. I was aware of the 500/600mm but was unsure if DNO's had to adhere to a seperate set of reg's.. Either way its not good. But for them to bill him as well is bizarre. Ill await the results of his legal advice with interest, and just be thankful it didnt result in anything more serious.

 

[Engineer54]

What your friend could possibly have as a defence with, is if the DNOs cable wasn't protected by cable tiles or bricks. Especially if the cable wasn't buried deep enough through occupied locations ...ie a domestic garden!!


So what sort of depth was it when your friend hit the cable ....more or less than 600mm???

 

[IQ Electrical]

If the cable was actually at a depth of 200mm and not protected/identified then I'd be arguing the ---- with the DNO.

As Engineer54 has stated, if the area is a domestic garden then it is reasonable to expect the ground to be disturbed by digging etc. and with this in mind, I would argue that the DNO had a duty of care which obviously wasn't exercised!

I'd also be making a bit of noise on the fact that your friend has actually had a near miss as far as health & safety is concerned!

 

[rocker]

Who has quoted BS:7671.??? 600mm is the nominal trench depth for cable laying. Normally the cable manufacturers will also quote this depth, when stating current ratings of cables for direct burial....

I've used this depth for so long now, that if it is in the BRB, ....I've never noticed it ...lol!!

Ian said 'there is no depth in 7671, however we normally go to 600 mil' I was pointing out that anything to do with 7671, whether in the book, any guidance notes or best practice guides, or simply inferred doesn't matter, and we would need to refer to the DNOs regs.

 

[IQ Electrical]

I found something in ESQCR 2002 Regulation 14:

"Cables must be buried at sufficient depth to prevent danger and they must be protected or marked."

DTI Guidance on ESQCR 2002 states that "In consideration of the methods by which cables should be marked or protected, duty holders should make allowance for the environment in which the cables are installed and the risks to those who may need to expose and work on or near the cables in future"

 

[Knobhead]

I had to run 4 400mm 3&½ SWA they had to run under 2 railway lines and a road. We had the trench dug at 1500mm depth then laid 4 x 6” welded steel pipes for the cable to go through. At the LV switch gear end we welded 16mm studs to the pipe and connected them with 95mm singles to the main earth. That sub had the best earth path on the site!

 

[SimpleSimon]

I had to run 4 400mm 3&½ SWA they had to run under 2 railway lines and a road. We had the trench dug at 1500mm depth then laid 4 x 6&rdquo; welded steel pipes for the cable to go through. At the LV switch gear end we welded 16mm studs to the pipe and connected them with 95mm singles to the main earth. That sub had the best earth path on the site!

Not a fence post getting through that!lol.
Seriously though that cable should have had a cable identifier over it at that shallow depth.

 

[ian.settle1]

The DNO don't have to work to BS:7671.

Second that