ECN Forum Forums General Topics of the Trade General Discussion Area Power lines

Hi Elektroinstalacje, and welcome to the forum.

There are many different voltage levels used throughout the U.S., more than in most countries due to the sheer size of the nation and the various electricity companies there.

Even at the low-voltage end of the scale there are several different systems: 120/240V 3-wire, 120/208V 3-phase, 277/480V 3-phase, 240V delta, etc.

I remember somebody posted a link to a document from Cooper Transformers a year or two ago which provided a pretty good explanation of some of the different HV systems in use. Can anyone remember the link?

Over here in Britain, our most common voltage levels are 240V 1-ph or 240/415V 3-phase, 11kV, 33kV, 66kV, 132kV, 275kV, and 400kV. There are still a few local distribution systems using 6.6kV, but these are quite rare now. There are other levels used for specific purposes, such as a high-voltage D.C. interconnection with France, 25kV A.C. for long-distance railways, etc.

Here are a few photos:

Typical 33kV line

Typical 11kV line

More 11kV local distribution

Overhead to underground transition with switch, also 11kV

Small pole xfmr on single-phase spur line

Typical 3-phase pole transformer

Same pole, showing secondary fuses

Typical pad-mount xfmr in wooden enclosure

All above transformers are 11kV primary, 240V or 240/415V secondary.

Typical 240/415V overhead distribution lines

(Poles in that last photo also have telephone lines lower down.)

Single-phase xfmr feeding 240/480V 3-wire distribution in rural area

All of the above are my own pics. Feel free to copy and use if you wish.

For the larger transmission lines (132kV and upward), have a look at some of the photos on this site:
http://users.tinyonline.co.uk/bigh/bigh/photoarchive.htm

This is 124kv on top. I think it is 50kv or so on the bottom
FPL Florida
http://members.aol.com/gfretwell/124kv.jpg

Hey pauluk1
I notice in your distribution pics there are only three conductors. Is your system a 3 wire delta rather than a 4 wire wye?

In most European countries anything above 230/400V is 3w delta. Saves a lot of copper.
The transformers have a delta primary and wye secondary with grounded star point. (class DYN)

And Pauluk supplied some pictures of a System that only exists in the UK, NZ aud Australia (or maybe not even NZ) - 230/460V single phase AC.

Yes, as TR says we don't distribute a neutral on any of our HV lines. They can be wye connected at source, but the neutral goes no farther than that. Thus even a single-phase spur line has to be run as two phases, as you can see in a couple of those photos.

The 1-ph 3-wire 240/480V arrangement (O.K., its 230/460 officially now) is found in rural areas where the xfmr has to serve a relatively small group of homes. All neighborhoods of any size are wired with 4-wire 240/415 (230/400) wye LV.

As Texas_Ranger says not being sure we use 1 Phase 230 / 460 Volts in New Zealand.

Yes we use it at the 2 phase 11 kV supplies and the 1 phase 11 kV SWER system.

I will post some piccies later

Elektroinstalacje search under Photos' , SWER in this forum and there are some SWER lines and transformers from NZ.
https://www.electrical-contractor.net/ubb/Forum5/HTML/001143.html

edited to insert link



[This message has been edited by RODALCO (edited 02-06-2007).]

Gidday there Elektroinstalacje,
Welcome to ECN, mate!.
Ray (RODALCO),
I would add to that list of voltages, the now defunct, but still in use in some areas, 1.1kV system.
It was used here in both Mid and South Canterbury, in particular in South Canterbury, when the old MED (Municipal Electricity Department) had the function of a utility in Timaru and places like that.
400/230V has all but super-ceded, this system, but remnants of it still do exist.
It came about before the 400/230 system and was used as a means of a distribution system for light commercial/industrial, the primary side of the tranny being 1.1kV, the secondary being 3 phase 230 + neutral.
Ray, I thought that the DC link was 500kV, has this been bumped up as well?.
If you do get the chance Ray, go to Benmore and see the rectifier banks that supply this link, I was down there a few years ago, it is an absolutely amazing experience.
I would have taken pictures but I didn't own a digital camera at the time.
The hum from that place is like being next to a humungous welder.

The list of voltage is as long as my shopping list today

Thanks everyone for answer.
If you have some interesting pictures about this and want to share it witch electricians in Poland please write to me. I'll put them to my web album.

Mike, interesting, didn't know about the 1.1 kV system but great it is still about in the South.

Elektroinstalacje,
A few more pics taken at local 33 / 11 kV substations in West Auckland while doing maintenance work.
https://i123.photobucket.com/albums/o298/RODALCO/DSC02276.jpg

33 kV OCB sabulite road
https://i123.photobucket.com/albums/o298/RODALCO/DSC02275.jpg

33 / 11 TF sabulite road
https://i123.photobucket.com/albums/o298/RODALCO/DSC02279.jpg

33 over 11 kV sabulite road
https://i123.photobucket.com/albums/o298/RODALCO/DSC02281.jpg

T 2, 11 kV bank sabulite
https://i123.photobucket.com/albums/o298/RODALCO/DSC00421.jpg

Triangle 11 kV bank
https://i123.photobucket.com/albums/o298/RODALCO/DSC00421.jpg

33 kV Bush rd tilted powerpole. 11 kV and 400 Volts were live. The 33 kV tripped.
https://i123.photobucket.com/albums/o298/RODALCO/DSC00208.jpg

sectionaliser 11 kV near Kaitaia
https://i123.photobucket.com/albums/o298/RODALCO/DSC01005Hsn.jpg

Henderson valley sub.

hope they work, had problems with spacing (RF)

[This message has been edited by RODALCO (edited 02-10-2007).]

[This message has been edited by RODALCO (edited 02-10-2007).]

Mike
http://www.transpower.co.nz/?id=4798

It runs at 270 and 350 kV each leg.

between two phases it is 620 kV dc.