Regulations re buried loop connections 1980

[Lectrician]

We ran some cables under a lorry hard standing a few years back as it was constructed.

If was originally a field, and the contractors dug us a 600mm trench, which then had a few 6" ducts chucked in on top of our cables for the future.

The trench was backfilled, and they then spread large rocks, finer rocks, finer rocks still and then dusty stuff, all rollered down. Reinforced concrete was then poured in sections.

A couple years later when we had to get to the ends of our ducts to add some cables, we had to excavate down to just under 1.5m to get to our ducts!

 

[westie101]

We live at No.8 on the even numbered side of a short cul-de-sac. Round the corner from No.2 in the 'main' road is a small building (not a box) which houses a "substation"/"transformer"/"distribution point" (?). The guys from the SEB told me that our supply comes via a loop from the fusehead at No.6 to our fusehead. Judging from the fact that there are also 2 cables going into our fusedhead, there is also a loop from us to No.10.

It was quite common to use loop services in that period and was dependant on the expected "After Diversity Maximum Demand" which for a typical gas heated, property could be in the order of 2kW. So looping a number of properties together was often used.

Incidently, westie, whats the largest size concentric cable used by dno's.

The largest single phase we use is 35mm2 Aluminium Cored and copper concentric, available in both plain and split concentric.

On each occasion plans have either not shown the service to the property, just the main cables in the street, or the positions sprayed by WPD have been incorrect!

I don't doubt it and know that some, often, older plans are very poor. Here we certainly do have accurate plans that can be trusted most of the time

 

[ban-all-sheds]

The cable to my house was replaced about 15 years ago it is about 6" deep.

holmslaw - there's SFA point in telling us what happens where you live. This discussion is about what rules/guidelines there are for cables in the UK.

 

[ban-all-sheds]

We live at No.8 on the even numbered side of a short cul-de-sac. Round the corner from No.2 in the 'main' road is a small building (not a box) which houses a "substation"/"transformer"/"distribution point" (?). The guys from the SEB told me that our supply comes via a loop from the fusehead at No.6 to our fusehead. Judging from the fact that there are also 2 cables going into our fusedhead, there is also a loop from us to No.10.

It appears that my neighbour is supplied via my house, like this:

Whether it loops onwards from his house I don't know. We are the non-conjoined neighbours in a row of semi-detached houses and the entry point to the houses is about halfway from front to back. A logical way to do it would be for the DNO cable to run along under the pavement, and then be T'd off to run under the driveways between the houses, into one and then looped to the other, rather than zig-zag up and down. That would mean lots of u/g joints though. But from memory the cable under the pavement is larger than the ones coming in/out of my house, so I guess they must be there...

What type of supply do you have? Mine's TN-S, and what bothers me is that if I'm right, and I can't see where else it would be joined, my neighbour's earth runs via my MET. I could, by design or accident, remove his earth, which can't be a happy state of affairs. Were I living in his house I'd be very concerned about my safety being in the hands of someone else like that.

Worse - which one is which? If I want to measure my Ze, which one shall I remove from my MET?

If my neighbour decides to measure his he's going to get a dodgy result and I'm going to get all of my extraneous-conductive-parts connected to line via his tester, albeit only briefly.

Actually - I think I'll post that one as a separate topic - somebody here must have had to measure Ze on an installation like that....

 

[holmslaw]

..

 

[TonyNorton]

Re: "Looped connections".

Are such connections part of a "ring main" type configuration, or a "spur"?

Tony N

 

[westie101]

Are such connections part of a "ring main" type configuration, or a "spur"?

A spur

It was all about cost, a single joint onto the main could have 4 service cables out of it, each service cable could feed up to 3 properties.
In those days cable costs were so low as to make this economic

 

[ban-all-sheds]

Mr Nasty, its a discussion by decent people about cable depths. Your nasty pointless contribution is not required.

The OP's property is in Dorset. The last time I looked that was in the UK.

His question, and the subsequent discussion, was about the depth that cables should be in the UK.

Your property is in the Wallis & Futuna Islands.

What is the relevance of the rules/procedures for electricity suppliers there to the OP's question and the subsequent discussion?

 

[holmslaw]

..

 

[ban-all-sheds]

I'm not trolling - I have a perfectly valid and important question, and your reply was not an answer.

What is the relevance of the rules/procedures for electricity suppliers in the Wallis & Futuna Islands to the OP's question and the subsequent discussion?

 

[holmslaw]

..

 

[TonyNorton]

Enough Guys,

this is starting to get abusive, and it was not my intention to start a ruck.

I asked a fairly, I thought, simple question to which I have had some useful answers and comments. From these I have surmised the following: -

There are 'Codes of Practice' and 'guidelines', which may or may not be observed, governing the depth to which domestic supply cables should be laid, but no actual Laws or Regulations, unless they be included in a local governing body's Building regulations.

The generally acceptable depth at which to bury a domestic cable seems to vary from 450mm (18") to 600mm (24") according to which DNO is laying the cables. The SEB, or the building contractor working on their behalf, laid my cable 250mm (10") below the surface, and that is measured at the point where it goes under the pavement!

I consider then, that I have sufficent information to justifiably tell them to get stuffed if they come after me for the cost of the repair.

As the OP creator I think that gives me a position equivalent to chairman of the meeting. As such I would like to thank you all for attending, and for your contributions to the meeting, and declare the meeting closed.

Please don't fall out with each other over over something I initiated.

God bless you all

and Thank You

Tony Norton

 

[JohnW2]

Please don't fall out with each other over over something I initiated.

.. and please don't you feel any responsibility - that pair are more than capable of "falling out" (which they seemingly first did years ago) without any help at all from outsiders!

I hope you got some useful answers before the thread went silly ... and have a good weekend!

Kind Regards, John.