Will this transformer work?

Folks,
I have a line on this three phase transformer. I want to step up 220V
three phase out of my 15 HP RPC to 480V so that I could power up my
recently acquired Brown & Sharpe #2 vertical mill made in the 50's.
There are many here who are in the know on industrial electrics. Can
I please have a quick review on the specs of this transformer in the
link below and verify for me that if wired 220V 3 phase on the
secondary, I could get 480V 3 phase out of the primary? Thanks.
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Reply to
trg-s338
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Yes & no. 1st - if you actually have 220 & not 240, then no. But you probably have 240 (most single phase is 240, I dunno about 3 phase). If so, then you could use the 504v taps & get 450 - 475v out. This is because of core losses. I'm assuming 5 - 10%, but that's a guess.
Good luck, Bob
Reply to
Bob Engelhardt
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Looks like it sure would work. You have plenty of taps to choose from. Probably, assuming you really have 240 V service, the 480 V tap would give you 480 V out, +/- a percent or two. Why not set up the idler motor to run off 480, and use a single-phase step-down transformer to feed it 480 from your 240 mains. Note that a 15 Hp idler would draw about 50 A reactive from 3-phase mains all the time it is running. I don't know how much worse that gets running it from single phase, but it almost certainly goes up. Without a big capacitor bank, the bad power factor might put out your lights unless you have a 400 A service, or have very little other load on a 200 A service. If you have to buy this transformer new, you really should look at a used 480 V VFD on eBay. The 480 V units go cheap. Then, get a 240:480 single-phase step-up and you are set. No loud noise, no horrible power factor, no energy waste, and you get variable speed, too!
Jon
Reply to
Jon Elson
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Good answer both gents.
Where does the OP live? I have some transformers available....
Gunner
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Reply to
Gunner Asch

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