Reverse Wired Step Down Transformer

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electriciansnet

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Hello all. I have an old client who is in the business of repairing high-end auto wheels and, although exhibiting bad planning and bad engineering, has just purchased this "oh so great" wheel polisher for tens of thousands of dollars. This equipment- originating in Germany is 60 Hz but its straight 460 at 1.5 kw nominal. The buildings service is 3 phase 240 delta (high leg present)



This is too big for a buck/boost so in order to achieve the 460/480 I need to reverse wire a step drown transformer. I have the freedom to install a 3,5 or whatever kva transformer I want at the panel but I need the secondary, which would be primary in this case to be 240 Delta. I tried hooking up an old 25 kva that was on hand with no load on it but most of the data was illegible except that the primary was multi-tap and the secondary was actually 230v. Needless to say it was a dirty, unbalanced voltage.

What is the most accessible; most used solution for this in the field? I have found a 3kva, 480v with a 240v 3 phase secondary for about a grand but I would like to know if this would provide the desired output or is there an easier "off the shelf" solution.
 
electriciansnet said:
Hello all. I have an old client who is in the business of repairing high-end auto wheels and, although exhibiting bad planning and bad engineering, has just purchased this "oh so great" wheel polisher for tens of thousands of dollars. This equipment- originating in Germany is 60 Hz but its straight 460 at 1.5 kw nominal. The buildings service is 3 phase 240 delta (high leg present)
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Germany, like the rest of EU land is 50Hz 230/400V. Was the equipment made for export?
Can it be tapped for different voltages?
 
First your primary will be 240
Second your secondary will be 460.
Third DIRTY POWER? Or you just had the connections wrong.


Call your supply house and order the transformer you need. Order a 240 Delta to 460 Wye,

Check out Hevi Duty's web site (see link below)

Look at Group G and make sure the transformer you order has taps so you can adjust for 460. And verify all the voltages for the new equipment.

http://www.solahevidutysales.com/general_purpose_distribution_transformers.htm


Or you can possibly do what you are attempting, get the name plate data and change taps and see if you can achieve 460 secondary. Off the top of my head it may be tough to get to 460 with a 480 Delta to 208/120 wye transformer. You will not need the neutral on the Primary (208), you will need to lift any factory grounds/bonds, you will need to corner ground the secondary (480), or if ungrounded you will need to install ground alarms.
 
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Yes the equipment was made for the states. Why straight 460, I do no know. Seems like it would substantially limit potential clients.

Grounding (to primary with service)should not be an issue . Not needing neutral.

I think I may have just tracked down a 3 kva 480 to 240 delta which should do the trick. It's supposed to be like new for a couple hundred.

Finally, I used the term dirty for lack of a better term. With the xfrmr that was on hand we has up to a 200v diff between 2 of the taps but that's a non issue on this thread since that xfrmr will not come into play

Thanks, for all of your replies. Much respect
 
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