Film-Tech Forum ARCHIVE: Xetron/IREM G3 power supplies

This is topic Xetron/IREM G3 power supplies in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Michael Schaffer (Member # 1204) on 06-15-2003, 09:26 PM:

I have a couple of these and they are designed for an input of 230VAC. The supplies I have are fed with 120VAC however. Which modifications to the unit not documented in the manual would this involve?

Posted by Jon Bartow (Member # 241) on 06-15-2003, 10:11 PM:

Michael,
In the US a single phase line is 120v to ground (a.k.a. a common receptical) 220v (or 230v, or 240v) lines have two more-or-less opposite phase lines that are each 120v to ground but 220v relative to each other (or 230v or 240v). A standard 3-phase setup is 208-230v phase-to-phase with each leg ~120v to ground. All US power runs at 60hz.
The IREM G3 power supply wants 208-230v 3-phase power. Sorry, you can't modify the unit to work on 120v single phase.
(sorry if I repeated info about US power that you already knew, just covering the bases)
Jonathan

Posted by Michael Schaffer (Member # 1204) on 06-15-2003, 10:20 PM:

Thanks very much for your input. I read about this before I came here, but too be honest, I forgot in the meantime! My head is swimming a little bit because in the US, everything is just a little bit different. Miles, ounces, pounds, inches...It takes a while to get used to all the differences!
Still, I measured the 120VAC at the power supply input and it is fed through a single 3 phase breaker. What am I overlooking?

Posted by Dave Macaulay (Member # 813) on 06-15-2003, 11:09 PM:

If you have a 3-phase panel and you can get 120V from it, in the USA it's almost certainly a 208VAC 3 phase supply. You should get 120V to neutral/ground on any of the 3 line wires and get 208V between any 2 of the line wires.
If you really get 120V between 2 line wires in a 3 phase panel, something is fishy.

Posted by Michael Schaffer (Member # 1204) on 06-16-2003, 05:29 AM:

Everything seems to be fine. I get 120V (+/-2V) on each phase and 208V between each of the phase combinations.
I was just confused by the terminology because in Germany, standard voltage is 230V 50Hz and the phases for this type of input are 120 degrees apart. The manual actually says 208/230VAC 60Hz and I had misinterpreted that as the type of input I am used to (even more so because IREM is an Italian manufacturer). That confused me even more since I had of course informed myself about American power standards.
The manual has the part lists for European and American variations on the same page and I let myself be confused when speed-reading it rather than looking carefully.
My original question: what modification would the unit have for American standards can also be answered by comparing the parts used for either input.
I seem to have confused the usage of the terms line and leg. A 230V line that has actually 120V on each of the two combined LEGS makes sense, but I thought Jon meant a single physical connection...

Thanks for clearing that up!