I've noticed several new pole-mount transformers in my area of a type rather different to those we've been used to seeing over the years, so it looks as though the PoCo has switched to this type for replacements.

Can anyone identify the make?

Paul,

We've had xformers like that for quite a long time.

I'll see if i can get a picture of an old weather beaten one somewhere.

I think they're made by ABB.

...

They're used for remote small industrial 3-phase drops and also for providing power to small villages (bends in the road with a few houses, a pub, a police station and a post office)

paul or dave

is the transformer connection like delta primary and wye secondary ???


merci , marc

Marc,

Yes, it's 11kV delta primary, 240/415V wye secondary (or as this is a new xfmr, it may well be that the secondary is designed for the new nominal standard of 230/400V).

There is never a neutral on HV distribution lines in Britain, so all primaries are wired delta.

Paul,
Dave is in fact right about the brand of the transformer.
It is indeed an ABB Oil-filled 317 Series Distribution transformer.
We've actually got a few of these over here, used on Industrial sites.
Just a little note on the use of Star and Delta configurations in Distribution Systems, over here Star is used on the Primary winding in some places in the Network where the Transformer is required to be referenced to Earth.
The Earth is taken from the normal Star-point of the Transformer.

At school we were told 10 and 20kV distribution networks in Austria usually have a delta configuration, whereas systems with voltages exceeding 20kV (usually 110kV or 220kv) always have a star configuration. 230/400V supplies are usually star.

Presumably you mean that the originating windings on the higher voltages are wye (star) configuration but loads are still delta connected. If so, then I wonder if the lower-voltage lines are referenced to ground in any way.

The Cahier Technique paper on MV Distribution Systems has a table showing some of the grouding/neutral methods used, but doesn't include an entry for Austria.

Just an addendum to my original post.
It's interesting to see them spark gaps on the bushing insulators.
We don't use them here on our trannies for some wierd reason.
A very worth-while accessory in my opinion.
And there's more of that funny green wire.
BTW Paul, what is that wire heading downward at an angle from under the base of the transformer?.
It looks like a stay wire, but it's point of attachment looks too "flimsy" for it to be one.

Yes, it's a fairly common stay arrangement. You can't actually see the point of attachment in the first photo.

The part of the bracket just visible to the left of the xfmr is a loop through which the wire passes. It's anchored higher up the pole.

That arrangement is also fairly common in the States and Canada if I remember correctly. The general idea seems to be to allow the stay to be anchored into the ground closer than would otherwise be practical.

Ahh,
Thanks for the answer guys,
Over here, the stay wire is wrapped around the pole twice and then wrapped into the stay wire itself.

Mike,

Here's a picture which gives a better view of this type of guy-wire arrangement:

Over here the guy wire comes out a bit lower down the pole and goes out at a much wider angle than that.

In some mountainous areas it may be more than one wire too.

It's very rare to see a crooked electricity pole, however, the old wooden telephone poles here are being very badly maintained by eircom since privatisation.

They've their multicore distribution cables strung along them in rural areas and in some remote spots the poles are quite litterally falling apart.

Back in the 1970s & 1980s (pre-privatisation) they dug trenches and layed ducts along the edges of fields (i.e. beside the "ditch") and these carry optic fibers as well as bundles of phonelines. The overhead stuff generally only carrys smaller bundles of pairs out to customers and to be fair, despite the fact that it's strung along rather loosely, it doesn't seem to cause any faults.

I just think it's a pity to see the old poles deteroriate and be replaced by steel. The wooden ones look much nicer and are more sympathetic to their sorroundings.

Talking of Irish telephone poles. You probably didn't realise it but it was the Irish Post Office that discovered the very large Lisheen zinc deposit.

They were replacing a badly leaning telephone pole and on pulling the old one out found lots of orangy-black crystals coating the rotton wood. It turned out to be sphalerite - zinc sulphide - and an important ore of the metal. Oh the luck of the Irish!

It's alloy weight to Tipperary!

P&T (Post and Telegraphs) were possibly one of the most useless organisations in history.

It's a good thing they discovered something !

They were abolished in the early 1980s due to their complete inability to do either of their core functions. The mail was always late and the phones never worked.

Despite their tens of thousands of employees (there were only a few people who didn't work for P&T) they were taking up to 2 years to install a phoneline. Businesses were going bust because they couldn't get access to decent telecommunications infrastructure. Phone charges were astronomically high and they were on strike most of the time.

It reached a national crisis level by the early 1980s and the whole organisation was scrapped. Telecom Eireann (now eircom) established and the whole network digitalised in a very short space of time.

So, obviously "the lads" were out digging holes in the ground and doing amature geology when they were suppoed to be putting up a phoneline!



Apparently a team of at least 3 guys would arrive to install an extension socket.

There was a theory in the late 1970s that P&T actually had more employees than working telephone lines!

[This message has been edited by djk (edited 05-14-2005).]

Interesting picture Paul.
Reason I say that is, because any force on the guy wire would be borne by the end of that bracket, not by the guy-wire as it should be.
Just my opinion.

Trumpy, you're right. As the anchor point gets closer to the pole, the force the staywire has to apply to check pole-top movement increases exponentially. I think this is done simply to get a better fix on the stay-to-pole top by making the angle more acute, while keeping the base area of pole and stay in as small an 'envelope' as practical. This is ok, as long as the wire is stressed within its elastic limit and the anchor is firm enough to take the load.
The 'bracket' simply gets a compressive load, and is stressed-out as a strut.
Alan