I came across this power pole on a tiny rural back lane some weeks ago, but didn't have my camera with me at the time.

I was out that way again yesterday so I took a slight detour to get some pics:



It's a standard 11kV distribution line, but it sure looked a little different which is what made me take a closer look.

On top of the cross-arm are fairly standard-looking air-break switches, with an operating rod and padlocked handle mounted near the bottom of the pole, such as might be found anywhere:



But what's that other equipment? A round unit with six HV terminals connected to each side of the lines:



To the right of that is a small transformer tapped across two phases and feeding down to a steel equipment cabinet near the bottom of the pole.

Just to the left of the pole and slightly above the barbed-wire you can see a small radio antenna.

Could this be a radio-controlled system to allow remote switching?

Paul,
You are quite right actually.
This sort of thing is used for Automatic Sectionalising of the HV lines during Faults, so that the whole peocedure can be done from the Control room.
And it saves us Faultsmen, rushing around opening and closing Air Break Switches, and allows us to do useful things like checking the Drop-out fuses along a given road.

A techno-buzzword for this arrangement is SCADA, “supervisory control and data acquisition.” The 6-bushing round can is typically a sectionalizing switch. Many out west are standalone, with local controls to “test” the line by a recloser, for often overhead-line faults are temporary; caused by lightening, tree or bird contact.

Earlier radio was single direction, in that the control room could transmit an open/close command with only indirect indication of switch operation—i.e., the neighborhood lights came on. More recent is fully duplex/bidirectional radio, so when a close command is sent, in a few seconds it sends back a confirmation from a mechanical auxiliary contact buried in the sectionalizer. If there is low-voltage AC closeby, {less than a few spans away} the switch auxiliary power is derived from that, but in more remote situations a local control-power transformer is installed.

It is expensive to install this type of switching, but if there is a history of temporary faults in an area, they are worth the money. Besides, having to get out in the middle of a windy night to manually operative a switch is not too “convenient.” Especially in bad weather, troublemen can be very opinionated about when and where the next one is needed.

Thanks guys. I figured that this had to be some kind of remote sectionalizing arrangement, but hadn't come across one before. Of course, in England we don't have places anything like as remote as out West, or even NZ, and everything tends to be on a much more compact scale.

This pole, however, is located in what could be termed a remote location by English standards: Two or three road miles out of town, down some of the narrowest and twistiest back lanes in the area.

The line going off to the right in the first photo feeds across an area known as High Hill. This being Norfolk and fairly flat on the whole, high is a relative term, but it is certainly higher and more open, exposed ground that much of the surrounding area, so maybe this line is more susceptible to damage in winter.

Couple that with the "remote" location and it makes sense.

P.S. For those with a UK road atlas, this is the area between Stalham and East Ruston, Norfolk.


[This message has been edited by pauluk (edited 06-19-2004).]

Well what d'ya know? I found another one!

After this set-up and the 3-wire 240/480 I've been looking a little more closely at overhead wiring to see if I've just been missing things that were right under my nose!

This remote switch is about 15 miles from home, but you can see the whole setup with equipment cabinet and antenna a little more clearly:

A couple of notes… The concept of automatic reclosing applies only to overhead distribution and transmission lines, with mostly short-lived faults from lightning and tree-branch exposure. Temporary faults are just about unheard of in underground systems, as is obviously the case for premises {inside} wiring.

Depending on age, sectionalizers may use mineral oil, sulfur hexafluoride gas or vacuum for insulation around the 11kV contacts.

The custom "squirrel fence" in the third pic looks handy.

Those little barbed wire fences are fairly common. Here's a transformer you've seen before which has them on the poles:

Hello

As this is my first post allow me to introduce myself. I am an electrical engineer working for the distribution company on the Isle of Man ( a small island in the Irish sea between the UK and Ireland ). I deal with all voltages from 230V to 90kV and work on maintenance and faults. I've been following the forum for a while now, and have found some useful information on it, and loads of very useful photographs!

Back to the images - on the island we use reclosers as shown in the photos together with smart links or sectionalisers. These can be programmed to drop out after a set number of trips in a certain timespan.

In most rural areas auto reclosers are fitted at the primary susbstations where the 11kV leaves the substation. They will also be fitted as bjarney says in areas which are prone to overhead line faults, together with the sectionalisers. This allows the fault to be cleared quickly, and means the power is restored to the majority of people before they can even start dialling the fault numbers.

We have numerous reclosers and sectionalisers on our system, even though the island is only 30 miles long by 15 wide. It keeps the CML down a treat and allows you to pinpoint the area of the fault much more easily by only getting calls from the vicinity of the fault.

Have a nice day

Ian

Hello Ian, and welcome to the forum.

Your description of your local network set me wondering whether the island has a higher than average incidence of thunderstorms and strong winds, given your location in the Irish Sea.

I remember several years ago seeing a whole page of storm instructions in the front pages of a Manx telephone directory, which seems to support that.

For those not too familiar with the British Isles, here's a map which shows the island's location:

Hi and welcome Ian!

I'll instantly take the chance to verify the information I have my database: Does Isle of Man use 230/400V with BS1363 plugs?

pauluk - the island has its fair share of thunderstorms, most of them tend to stay just offshore thankfully. Wind is plentiful here, which is nice when you have a traction kite! The map is slightly inaccurate in that it shows the island as being part of the UK, which it is not. The island has its own government (the oldest democracy in the world) and is classed as being part of Great Britain, not the UK, or the European Union come to think of it.

C-H - yes we use the same standards as the UK, but as our Electricity Supply Regs are yet to be updated we officially still use 240/415V although we aim for 230/400V. It gets a little confusing sometimes.....

I figured it might be something like that.

And yes, I noticed the slightly inaccurate labeling on the map. Isn't the IoM officially classed as a British Crown Dependency?

By the way, that map is also inaccurate with the U.K. tags applied to Jersey and Guernsey. They share a similar status in being British territory, but not part of the U.K. or the E.U.

Hi there Ian, welcome to ECN!.
Did you guys know, that those little fences that they put aroud poles are not to prevent animals climbing the poles.
It's people they try and keep out, as well.
Over here, we use a single band of 500mm Stainless sheet around the poles to stop the possums and other wildlife climbing our poles.
The band is mounted at 3 metres from the ground.

Known affectionately as ARSS 's!! Auto reclosure section shunts.

They are the replacement of automatic break-makes found all over the OH system in remote areas which would reset themselves a preset number of times (usually 3) under fault conditions before locking out until manually reset. Usual cause was trees/conductor clash, so if the fault was clear ( ie the branch fell to the ground ) the shunt stayed in and everyone was happy!

Ours, in the Lakes, can be remotely switched from Manchester Control ( used to be Carlisle ) and are used to divert/isolate for linework, but they still drop out in fault conditions with the autoreset function.

Typical of this country though; if a crew requests a dead line, Manchester switches it, but a man still has to go and visual the unit to check it's open!! :roll eyes Same applies at 3.00am in fault condition - the lights might be out and the signal red in Manchester, but someone still has to check even if the ARSS is 10 miles from the tree branch hanging in the lines...

Oh well...better safe than fricaseed. Hope that helps a little

[This message has been edited by uksparky (edited 07-07-2004).]

Interesting. I knew that we'd had the auto-reclosers for a long time, and they seemed to be especially useful when I lived in Cornwall in the 1980s as outages were quite frequent.

Having somebody go out to the unit to check that it's opened the line seems to defeat the whole point of having remote-control. As you say though, how typically British!

What would be wrong with the following? Crew requests dead line, control center sends command to open the remote switch, crew at work point tests line to check it's now dead. Too simple?

By the way, is this still 11kV circuits you're referring to which are controlled from Manchester? Higher voltage transmission lines I could understand, but it seems rather a long way away for the control of local distribution circuits.


[This message has been edited by pauluk (edited 07-08-2004).]

Like Ian mentioned, you can add sectionalisers downstreams the reclosers. It senses overcurrents but doesn't do anything about it until the recloser opens. When the power is off, it opens. When the recloser closes, the rest of the line gets the power back but the section downstreams the sectionaliser stays off. The idea is that these things are simpler and cheaper than the ARSS's/reclosers.

I'm sure Ian can tell us more

The recloser in these pictures is a Whipp & Bourne GVR (made in UK by FKI) with a Panacea control (made in USA by SEL).

The GVR uses vacuum bottles insulated in an SF6 tank as someone mentioned in their post. Very nice device, but very unique in its apearence.

I think in one of the pictures you can see an antenna, so they must have this one fitted with a radio for SCADA comms.

These controls store all of the same data whether they have radios or not, but the radio allows remote retrieval of the data, polus remote metering and control.

Very useful devices, they can give you a very accurate distance to the fault that helps a lot in systems without a lot of lateral. On transmission (high voltage) systems, these types of devices can locate the fault within a line span or less. Lots better than driving the whole line to look for a problem.

QUOTE

Lots better than driving the whole line to look for a problem.

END QUOTE


Not on double time it isn't.

Ian

The rural networks in the Republic of Ireland are currently undergoing a pretty massive upgrade project. Infact, the single biggest electrical project since rural electrification took place originally!

I'm not 100% sure what kind of sectionalising arrangements are being put into the newly upgraded parts of the network.

The ability to automatically reset after faults has been around for quite some time.

The massive network investment's being driven by huge growth in power consumption in Ireland over the past decade the economy's booming and the population's growing quite fast too. (more than doubled since 1988!)

E.g. there were 90,000 new customers connected to the network last year! (Ireland's total population's only 4 million. so that's a hell of a lot of extra connections in a year)

There has been very signifigant growth outside of the major urban areas, particularly as Dublin's commuter belt's expanded but a smaller towns have also seen their own organic growth. All of this is pushing the capacity of the existing infrastructure to its limits.

They've also replaced over 65,000km of the MV network in the space of 5 years.. so quite a busy time if you're a linesman over here

I'll try and find out what kind of stuff they're using in terms of automation in remote areas and post when I do

Actually speaking of pictures.
I'm doing a fair bit of pre-Winter patrolling/Inspection of the lines in our district at the moment, should be able to get at least a few pics of the stuff we use here to carry the buzzing Ergs through.
I'll see what I can come up with.

Paul,
Just looking at the 3rd and 4th picture you posted above.
That's a rather strange way of connecting the tails to the overhead lines.
Usually we just put a line tap over the whole line and then slide the tail in and tighten.
Your method over there looks a lot neater though!.
Ian,
How many people live on the Isle of Mann?.
Must get cold there in the winter. BRRRR!.