Is there a maximum distance between DNO cutout and the meter ?

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countryman69
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Is there a maximum distance between DNO cutout and the meter ?

Post by countryman69 »

Current situation

DNO cable {> cutout > meter > fused isolator} > cable (1/3 mile long to the house) {= meter box }

Can I change it to this ?

DNO cable {> cutout > fused isolator} > cable (1/3 mile long to the house) > meter > consumer unit etc

TIA
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Someone-Else
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Is there a maximum distance between DNO cutout and the meter ?

Post by Someone-Else »

What do you mean by fused isolator?

The consumers unit must be within 3 metres of the meter/main fuse.
However if an isolator is fitted after the meter, the cable to the consumers unit can be as long as you like, so long as it is the correct size and protected.

Below is a picture of an isolator, it has no over current protection, all it does is isolate when operated. Quite often found in the intake / meter room of blocks of flats.
isolator.jpg
isolator.jpg (26.53 KiB) Viewed 2410 times
You can't move anything that is not yours, i.e, main fuse, meter.

Nothing says you can't have your own meter as well, but you will be charged by what the first meter says.

The reason you can't have the set up the way you ask is simple.
If you had it as you ask, what is to stop anyone joining the cable and getting free electricity as they would be joining BEFORE the meter.
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Is there a maximum distance between DNO cutout and the meter ?

Post by Neelix »

Someone-Else wrote: Fri Oct 08, 2021 4:45 pm
However if an isolator is fitted after the meter, the cable to the consumers unit can be as long as you like, so long as it is the correct size and protected.

You can't move anything that is not yours, i.e, main fuse, meter.
Not sure I agree with the first sentence. A simple isolator does NOT allow a longer cable to be run.

In this scenario, if the meter remains in the current location a switch fuse, like there currently is MUST be installed, and this is after the meter, and before the submain


And IIRC the op has already stated the cable to his home isn’t the correct size so all this could turn out rather more expensive than they imagine

The OP needs a local spark to guide the process and advise
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Is there a maximum distance between DNO cutout and the meter ?

Post by Someone-Else »

Neelix wrote: Fri Oct 08, 2021 7:31 pm Not sure I agree with the first sentence
'Fraid its true :-)
As I said, I have seen it done countless times in blocks of flats in the main incomer/ meter room. The main incomer feeds all the meters for the flats and each meter has an isolator on the outgoing side.

I was trying to find something in print when I found..........
Bob225 wrote:therefore the customer shall provide and install an intermediate switch fuse or isolating switch if the distance between the meter and consumer unit is greater than three metres.
Taken from here :-)
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Is there a maximum distance between DNO cutout and the meter ?

Post by Neelix »

Someone-Else wrote: Fri Oct 08, 2021 7:47 pm
Neelix wrote: Fri Oct 08, 2021 7:31 pm Not sure I agree with the first sentence
'Fraid its true :-)
As I said, I have seen it done countless times in blocks of flats in the main incomer/ meter room. The main incomer feeds all the meters for the flats and each meter has an isolator on the outgoing side.

I was trying to find something in print when I found..........
Bob225 wrote:therefore the customer shall provide and install an intermediate switch fuse or isolating switch if the distance between the meter and consumer unit is greater than three metres.
Taken from here :-)
Don’t agree it’s ok. I think you may be mistaking a switched fuse for an isolator

Over 3 meters and additional protection is required. This isn’t down to BS 7671, it’s down to the rules dictated by the network suppliers
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Is there a maximum distance between DNO cutout and the meter ?

Post by Someone-Else »

I guess we will have to agree to disagree.
Above are my opinions Below is my signature.

Would you hit a nail with a shoe because you don't have a hammer? of course not, then why work on anything electrical without a means of testing Click Here to buy a "tester" just because it works, does NOT mean it is safe.

:mrgreen: If gloom had a voice, it would be me.

:idea1: Click Here for a video how to add/change pictures


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Is there a maximum distance between DNO cutout and the meter ?

Post by Scotty001 »

countryman69 wrote: Fri Oct 08, 2021 3:42 pm Can I change it to this ?

DNO cable {> cutout > fused isolator} > cable (1/3 mile long to the house) > meter > consumer unit etc

TIA
Thecnically YES, practically NO
To do this you would need to have your current service and supply terminated
Engage an ipc to install a new service to cut out and isolator, run a sub main to your property and have a mop install a meter. (not likely to happen as ipc tend not to take on a single premesis job, it's not worth it to them as it's too small fry work, (akin to getting an airline manufacturer "Boeing" to personally build you a 1/1000 scal model remote control 777) but if you could find such a desperate ipc the costs would be eye watering (anyone agreeing to pay that cost should be held in a pshyc ward)

Then you would need the DNO / idno to adopt the installation (including the submain) or to take over responsibility of the submain keeping to mop and DNO regulatory standards (I'm not sure if you could do this yourself or would need to employ a contractor with the accreditations to take this on ie ongoing annual cost)

If your'e looking for the meter to be in the property /on the wall of the property why not get a service alteration to extend the current service from its current position down to your property? It will be far cheaper THAN what you asked for and A LOT less hassle.
The issue / stumbling block with what you ask for is is the sub main with meter attached to it (> cable 1/3 mile long to the house > meter > consumer unit)

From my experience
Meter tail DIRECT to cons unit or isolator switch can be a max of 3m.

Tail (sub main) from isolator switch to cons unit can be as long as you want them to be as long as they are the correct size and cable for the application. (swa if running outside and underground)

DNO is responsible for service cable and service head as well as the cut out unit and fuse.

MOP IS responsible for tail from cut out unit into meter, and tail from meter into isolator switch. (max 3m<)

YOU are responsible tail from meter DIRECT into cons unit (3m<)
The isolator switch (even if installed by the MOP)
Tail (sub main) from isolator switch to cons unit (as long as you want it to be as long as its the correct size and type for application)

In blocks of flats (If a full DNO instalation where the DNO is responsible for all but the meter)
, they may have an incomer from the DNO, into a ryfield unit / mdsb dist board with cut out fuses (in larger developments there may be more than 1 incomer) from this point 2 options
1) sub main to each floor that goes into another ryfield unit / msdb, with another sub main out of each cut out into individual meters (ideally each meter position should have a solid link cut out below it (red head cutout) for easy isolation BY MOP, or they may install a standard cut out with a fuse)
The downside to this setup is if a fuse in the 1st ryfield unit / msdb activates several flats will be affected at the same time.

2) incomer into ryfield unit / msdb, sub main from ryfield unit /msdb direct to individual meter positions with a solid link cut out (red head) below the meter for easier isolation by the mop.(or they may Install another standard cutout unit with a fuse)

It gets more complicated (in relation to who owns and is responsible for what) if icp's idno's or bno's get involved but for this general topic you don't need to go into that
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