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#142397 - 01/10/05 08:56 AM New supply -- Awkward location
pauluk Offline
Member

Registered: 08/11/01
Posts: 7693
Loc: Norfolk, England
Just been called upon to examine this one.

The property is located out of town on a country back road, about 3 to 4 acres of land. The land is longer than it is wide, going back a long way from the road, with woods down one side and to the rear.

There is no power on site at present, and the owner (who runs a small log business there) just has a small mobile home on the site with a generator and small wind turbine/inverter setup.

He's going to build a house up near the road, and to run power from that direction would mean new poles and cabling back along the road about 1/4 mile, to where there is already a large (probably 100kVA or more) 3-ph pole-mount xfmr feeding a farm on the other side of the road. Apparently he's been told "Something in the region of £20,000"

However, just behind the far corner of his land is another house, accessed by a road from a different direction, which has its own pole-mount single-phase xfmr at the end of a single-phase 11kV spur line which comes in from a different direction.

It would mean upgrading the transformer (couldn't see the rating, but clearly small), but it's only about 50 ft. from the corner of his land.

So, if he could build a suitable enclosure for cut-out and meter, and then take over responsibility for getting power from there up to where the house will be, I reckon he should be able to save a substantial amount of money. Cable will be costly for this sort of run obviously, but as he already has mechanical diggers etc. he would be able to provide all the heavy labor himself (hey, you think I'm going to dig a 200 yard trench! ). As I see it, it's got to come out less than 20 grand!

I've never had a job in this sort of position before, so before we get the engineers out to assess, do you think the PoCo would have any objections?

It would mean the meter being 200 yards back of the road at the bottom of the land, but there are houses with long private drives which would involve a trek from the road just as long, so I can't see why there would be any problem.

Any of you had a similar job and run into any difficulties?

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#142398 - 01/10/05 02:54 PM Re: New supply -- Awkward location
lyledunn Offline
Member

Registered: 06/30/02
Posts: 159
Loc: N.Ireland
Paul,
I worked for the power company in N.Ireland (NIE). Dont assume rational, logical determinations. Do assume nebulus obfuscation!
_________________________
regards

lyle dunn

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#142399 - 01/10/05 03:31 PM Re: New supply -- Awkward location
Trumpy Offline

Member

Registered: 07/05/02
Posts: 8540
Loc: SI,New Zealand
Hmmm, that's a real tough one Paul!.
Just a couple of questions spring to mind.
Is the HV line system at the front of the property actually passing the front?, or is it a Spur that ends before your customers property?.
I'd go with the rear supply idea, if it were possible, but at the end of the day, it will be the PoCo that has the final say.
Rural supplies are never the easiest systems to design and even the simplest system can cost a bundle.
Another thing to consider, is the fact that the Spur line to the rear of the property may have been installed with only enough capacity for the single load on it, as strange as it seems, PoCo's do silly things like this, especially where profit is concerned.
_________________________
Let's face it, these days if you're not young, you're old - Red Green grin

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#142400 - 01/10/05 03:46 PM Re: New supply -- Awkward location
aland Offline
Member

Registered: 05/20/04
Posts: 187
Loc: United Kingdom
Paul, It all sounds feasiable, but you can rest assured the PoCo will have a thousand good reasons why you should spend 20K. Seriosly though it all sounds OK to me, But the sub main's gona be a mother to allow for volt drop on 200 yards, might have to restrict him to one light at a time!! Go for it get the PoCo engineers down I have always found them quite helpfull.BY the way, You wont forget to hsve a word with building control as well will you though. ONLY JOKING. Good Luck Mate.

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#142401 - 01/10/05 04:39 PM Re: New supply -- Awkward location
Trumpy Offline

Member

Registered: 07/05/02
Posts: 8540
Loc: SI,New Zealand
LOL Alan!.
 Quote:
It all sounds feasiable, but you can rest assured the PoCo will have a thousand good reasons why you should spend 20K.

I'm hearin' ya loud and clear there!.
Yes and Voltage drop will be a concern, either way.
_________________________
Let's face it, these days if you're not young, you're old - Red Green grin

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#142402 - 01/10/05 05:31 PM Re: New supply -- Awkward location
uksparky Offline
Member

Registered: 07/06/04
Posts: 199
Loc: UK
Paul, there should be no problem with this at all - at least in my experience up here...

Get them to assess the site. Suggest u/g supply to the new property and get the owner to dig the trench and fill it back in. Up here they will change the tranny FOC if it's old enough to warrant it - or a nominal charge if not.

Labour aside, the only expense they will incur is the tranny and cable - no poles. I doubt if they will go for the 'remote cut-out' idea + private cable; but they might.

I recently did a job where the owner got the PMT and the last two 3-wire spans moved from in front of his house ( an old farm ). The 11Kv PMT was reused back 2 spans, they used one new pole, and the last span to the buildings was dropped u/g. It was self-dug. I'm told the total invoice was £5,200.00.
_________________________
If hindsight were foresight, we'd all be millionaires!

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#142403 - 01/11/05 02:52 AM Re: New supply -- Awkward location
pauluk Offline
Member

Registered: 08/11/01
Posts: 7693
Loc: Norfolk, England
Thanks for all the replies. More or less what I expected: Fine from a practical point-of-view, but the utility may have other ideas!

 Quote:
Is the HV line system at the front of the property actually passing the front?, or is it a Spur that ends before your customers property?

It's a spur line to the big xfmr for the farm which comes in from the opposite direction, so nothing running past the front of the land at all. On the other side of his land, beyond the wood, is a large manor-house type place. It looks as though that takes its power from an HV line coming in from the far side. It's quite infuriating, because there's power all round, just nothing in the little stretch where he's located.


 Quote:
Another thing to consider, is the fact that the Spur line to the rear of the property may have been installed with only enough capacity for the single load on it,

We did drive around the lanes and trace the line back. This 2-wire spur runs about a half mile from where its tapped from the 3-phase lines, and as near as I could make out, has about three houses on it, each with its own small pole-top xfmr.

Even if you put a full 24kW load on, it would only add an extra 2 amps or so to the HV current, so I can't see that being a problem. I'm not familiar with the guidelines used for our 11kV distribution system though, so the PoCo might have an objection I suppose.

 Quote:
But the sub main's gona be a mother to allow for volt drop on 200 yards, might have to restrict him to one light at a time!!

Yep, that's something I was concerned about. I did point out that when it comes to design it might be an idea not to count on electric for cooking and heat, but he was already planning on gas and oil heating anyway.

As a matter of interest, what size conductors are normally installed on overheads for local 240/415 distribution? I'd never really stopped to think about that before.

 Quote:
It was self-dug. I'm told the total invoice was £5,200.00

That's encouraging.

As you've all said, and as I told the owner, ultimately it's down to the PoCo playing ball. He needs power there one way or another, so we'll have to get them out and discuss the options. Might be worth asking about the option of the utility providing the feed right up to the front from the rear xfmr but the owner providing labor on the trenching.

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#142404 - 01/11/05 03:02 AM Re: New supply -- Awkward location
Trumpy Offline

Member

Registered: 07/05/02
Posts: 8540
Loc: SI,New Zealand
And another thing, voltage drop aside, no doubt the PoCo should be looking out for this, is the PSCC at the Main Switchboard, that will decide the Category of Duty of the MCB's used in the Consumer Unit.
_________________________
Let's face it, these days if you're not young, you're old - Red Green grin

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#142405 - 01/18/05 12:22 PM Re: New supply -- Awkward location
pauluk Offline
Member

Registered: 08/11/01
Posts: 7693
Loc: Norfolk, England
I doubt there will be a problem with MCB breaking capacities. I envisage a simple switch-fuse at the intake with a BS1361 cartridge fuse to the feeder.

By the time we get to the far end of the 200-yard subfeeder I suspect the PSCC will not be all that great.

Anyway, he's going to contact the PoCo and arrange an inspection visit at a suitable time for all of us to be there.

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#142406 - 01/22/05 09:13 PM Re: New supply -- Awkward location
Trumpy Offline

Member

Registered: 07/05/02
Posts: 8540
Loc: SI,New Zealand
Any news Paul?.
_________________________
Let's face it, these days if you're not young, you're old - Red Green grin

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