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.
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.
[This message has been edited by Trumpy (edited 02-15-2006).]
Re: Non standard voltages#145013 02/15/0606:54 AM02/15/0606:54 AM
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.
Re: Non standard voltages#145018 02/15/0602:32 PM02/15/0602:32 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.
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.
The product of rotation, excitation and flux produces electricty.
Re: Non standard voltages#145019 02/17/0610:13 AM02/17/0610:13 AM
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.