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Posted By: RODALCO Non standard voltages - 02/15/06 09:48 AM
Today I had to install a datalogger on the network transformer at the tunnel drilling site for the Puhoi tunnel, north of Auckland on SHwy 1 to monitor for voltage dips on the 11 kV supply line which is at the end of a long rural line.

Also I had to load the fuses and do the 11 kV switching on the network switchgear as well as livening up the two mining transformers on site for the soak test, polarity, phase sequence and voltage checks.

The total consists of 4 transformers.

Network TF.3Ø 500 kVA. 11 kV / 240-415 Volts. 26.5 / 696 Amps.

Customers transformers.

Local site supply TF. 3Ø 750 kVA. 11 kV / 240-415 volts. 39.4 / 1042 Amps.

Machinery TF. 3Ø 600 kVA. 11 kV / 433 Volts.
31.5 / 800 Amps. ( 250 Volts P - N ) Dyn 11. impedance 4.41%.

Drill TF. 1000 kVA. 11 kV / 1050 Volts. 52.5 / 550 Amps. ( 606 Volts P - Screen ) Dyn11. impedance 3.92%.

The drill is driven from 3 x single core neutral screened cables.

Anyone else has some non standard voltages?
I can sent photo's of the TF. nameplates if anyone is interested.
Posted By: kiwi Re: Non standard voltages - 02/15/06 10:31 AM
Thats a helluva big drill Rodalco ! Why the 1050 volt transformer ? Is that the drills working voltage ?
Posted By: Trumpy Re: Non standard voltages - 02/15/06 10:50 AM
Maybe this is an NZ thing?
I remember working at Pareora Freezing Works.
We had a 355VAC screw-feed Auger.
In one of the worst smelling places of the plant I wound, by hand a 23kW Cuprothal and fin element for the entrial cooker.
I had to sleep by myself that night after I got home, that was in the 500V Cooker Plant.
On the other side of the Plant there was a 35V ELV sensor system, for the well sensors.
Everything was really screwed away from us.
We had a rep from Rockwell Automation come out there, he ran away.
I think it was our 98.5V control Bus that scared him.
They train too many reps in uni's these days. [Linked Image]

[This message has been edited by Trumpy (edited 02-15-2006).]
Posted By: Trumpy Re: Non standard voltages - 02/15/06 10:54 AM
Oh and by the way we wound our own motors at Pareora.
Posted By: pauluk Re: Non standard voltages - 02/15/06 12:31 PM
The 250/433V spec was common in Britain before standardization at 240V. In fact there are still xfmrs around here so marked, just set a little lower on the taps.

Although 250 x SQRT(3) = 433V, it was also quite common for it to be referred to as 250/440V nominal.

No idea about the 1050V though. That's a strange one!
Posted By: C-H Re: Non standard voltages - 02/15/06 03:29 PM
I recently sold some equipment in a special version for a customer with a 525V system.
Posted By: IanR Re: Non standard voltages - 02/15/06 05:01 PM
While on the subject of nonstandard stuff, has anyone come across any DC mains still in operation?
Posted By: Texas_Ranger Re: Non standard voltages - 02/15/06 05:44 PM
Hmmm... not so special, but a big technical school in Vienna (a real old one) ran on their own 127/220V transformer until the early 90s!
Think I already told you about the 150V receptacle at the rural substation.
Posted By: RODALCO Re: Non standard voltages - 02/15/06 06:32 PM
The drill is brought in from Australia for the crew who does the actual drilling for the tunnel.
So are the special transformers, all been M.A.F. cleaned and certified.

Quote
Thats a helluva big drill Rodalco ! Why the 1050 volt transformer ? Is that the drills working voltage ?
That's correct kiwi. That drill is fed through 3 x single srceened cables at 1050 Volts ac.

I'm not sure if the 1050 Volts is a mining voltage, perhaps one of our Australian members knows, I'm actually back on this site again in the next couple of days and will ask the drilling crew if I get a chance.

Trumpy, I can see that for those odd voltages too you have to wind your own motors, they are not off the shelve items.

Texas Ranger, that was an interesting topic too, was in the 127 thread I remember.
Posted By: pauluk Re: Non standard voltages - 02/17/06 02:13 PM
Just a thought, but in round figures 1050V would be the phase-to-phase voltage on a wye system with 600V phase-to-neutral -- 600 x SQRT(3) = 1039V. 600V is a standard voltage in a few places -- Canada for a start, so perhaps there's a link?

Re D.C. mains, I believe that some parts of India still use D.C.
Posted By: aussie240 Re: Non standard voltages - 02/18/06 11:19 AM
The last World Radio TV Handbook I have, which is mid 80's I think, mentions India having DC mains. In this day and age I find that impossible to believe, but I would be fascinated to know what sort of things are being run off it, if it really does still exist. It would be more believable if it was an industrial supply only and not for residential consumers.
Sydney had DC mains up until 1988 or thereabouts; 480V centretapped. BUT it was only in part of the CBD and by 1988 was only being used for lift motors. The general consumer mains in this area had been connected to AC in the 1950's.
Those charts showing world voltages and TV standards often have mistakes; I can recall Fiji having 220V 60 cycles and NTSC televsion in one of them. Nothing could be further from the truth; it's 240V 50c/s & PAL..I know I've been there...even the electrical fittings are Australian. Some travel websites are incredibly innacurate for this sort of information.
Posted By: pauluk Re: Non standard voltages - 02/18/06 12:00 PM
Quote
Those charts showing world voltages and TV standards often have mistakes;

Some of them are of dubious value, to put it mildly, although in their defense it seems to be surprisingly difficult to obtain reliable information about some of the more out-of-the-way places. I know that our very own C-H has had difficulties in that respect.

In fact I just checked his site and he has Fiji listed as 240V 50Hz, but NTSC TV standard. Perhaps a correction is in order?




[This message has been edited by pauluk (edited 02-18-2006).]
Posted By: TeesdaleSparkUK Re: Non standard voltages - 02/18/06 04:45 PM
I used to work in a mine in the UK. The equipment was from UK, USA and South Africa. Voltages used were 6.6kV for distribution, 3.3kV for Heliminers and 1100V for other mining machinery.



[This message has been edited by TeesdaleSparkUK (edited 02-18-2006).]
Posted By: djk Re: Non standard voltages - 02/19/06 01:17 PM
Paul,

Also many of those lists are extremely out of date. Many countries have standardised on 220-230V 50Hz or 110-120V 60Hz while they're still listed as using odd obsolete systems e.g. 127V 50Hz.

If you're using EU or US setup you've got access to a vast array of appliances. If you're on something weird, you're kinda limited.

Although, that being said, I'm sure there are still one or two far flung places with odd voltages out there.

127V 50/60Hz can cause damage to some US appliances and 250V 50Hz can damage some EU appliances.

If travelling to far flung non-listed type places, it's worth buying a cheap plug in voltage/freq meter and checking the local conditions before plugging anything valuable in!

If you're travelling to W. Europe or N. America, Aus/NZ, most of S.E asia etc you'll be fine. You'll get what it says on the tin. I'd check in parts of Africa, south america, less developed parts of asia and definitley on small island-nations where older systems could still be in existance.

It's often far better to ask for local advice, e.g. the local electrical retailer, than relying on these guides.

Also, I'd suggest wiring a trailing socket (of your choice) to an IEC plug. Then you can bring a US plug and an EU plug.. and any other types can be easily purchased and connected locally... just buy (local plug) to IEC cable.. standard PC lead. It's a very workable sollution if you're ever backpacking across S.E asia etc

[This message has been edited by djk (edited 02-19-2006).]
Posted By: RODALCO Re: Non standard voltages - 02/21/06 02:43 AM
Have a look under " photo's for discussion"
PUHOI drill 1 & 2.

There are some piccies from the drill as well as some of the transformers and nameplate details.

Like the 1050 Volts AC.

Regards Ray
Posted By: pauluk Re: Non standard voltages - 02/21/06 04:13 PM
Links to Photos:

Puhoi Drill No. 1

Puhoi Drill No. 2
Posted By: Trumpy Re: Non standard voltages - 02/24/06 02:30 AM
Ahh thanks guys,
I'd forgotten to put that link in.
Time has been at a premium lately. [Linked Image]
Posted By: kiwi Re: Non standard voltages - 02/26/06 09:08 AM
Rodalco, I saw the Puhoi tunnel on the news the other night and there was footage of the big main drill in action. Awesome !
Posted By: RODALCO Re: Non standard voltages - 02/27/06 09:40 AM
kiwi
Cool!! what a pity, I missed it.
But ? ? it did trip the Waiwera feeder.
Auchh !
Posted By: Trumpy Re: Non standard voltages - 02/27/06 10:51 AM
Kiwi,
What channel was it on?.
I'm seeing if I can find some video on it. [Linked Image]
Posted By: kiwi Re: Non standard voltages - 03/02/06 09:35 AM
It was on 3 news last Monday night. An article on Transit NZ and the controversy surrounding their roading projects. I guess Transit NZ was showcasing their largest project to prove they are doing something to relieve the traffic congestion around Auckland.
Posted By: RODALCO Re: Non standard voltages - 03/02/06 09:50 AM
Thanks Kiwi,
I will try to get hold of a copy from TV 3, or a digital file.
I saw the machine at work yesterday, in very dusty and arduous conditions.
Cheers Ray
Posted By: granam Re: Non standard voltages - 03/10/06 04:30 AM
[i]Just a thought, but in round figures 1050V would be the phase-to-phase voltage on a wye system with 600V phase-to-neutral -- 600 x SQRT(3) = 1039V. 600V is a standard voltage in a few places -- Canada for a start, so perhaps there's a link?[/]

600V is a standard voltage in Canada, but it's a phase-to-phase voltage. The phase-to-neutral voltage on these systems in 347V. We also have 480/277V systems, but these tend to be older systems or equipment imported from the U.S.
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