Scott writes: >On Wed, 16 Mar 2005, Phil Howard wrote: >> On Wed, Mar 16, 2005 at 07:23:24AM -0500, shogunx wrote: >> | On Wed, 16 Mar 2005, Phil Howard wrote: >> | > | That part I have. What I do not have is 3-phase power to run it. >> | > >> | > What voltage and amperage does it need? >> | >> | 3-phase 440V most likely about 20-30 amps. >> >> You'll need at least 25 kVA. That's as much power as a small house. Then >> add air conditioning. Not sure whether upgrading electric service or buying >> a generator would cost more. Maybe renting one long enough to see if it >> will power up could be done. What are your goals for it? >> >> Is it literally 440 volts, or is that just a figure of speech for what is >> officially 480 volts (if you are in the US)? > >Well, according to ohms law, it should work at 440, though with a higher >current draw. You are correct. 3-phase each phase 120 degrees out of >phase from the others at 120V per phase yields 3 discrete 240V circuits >(actually about 208V after phase shift, but for all practical purposes its >the same thing, and depends on whether you use a wye or delta >configuration in your transformer). So figure of speech it is. In an >electic company FUD kind of way.
Even if 208 (derived from 3 phase service) and 220/240 (the normal single phase service found in homes and small businesses) are all not-too-far-apart, so that many times one can ignore the difference and some kinds of equipment will still run fine, it is not always the case - especially for equipment with motors. (It is my impression that switching power supplies are extremely tolerant of variations in input voltage.) I've been involved in situations where equipment which was specified for 220-240V required a "boost transformer" to run properly. --henry schaffer > ... P.S. the nominal single phase voltage in the US is 120V (or maybe 115V - or maybe even 110V :-) It is half of the hot-to-hot voltage (nominally 240V), and my local power company specifies +/- 5% for residential use and +/- 10% for other retail. ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
