3-Phase Test Rig, with step-up

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Not too much "electronics" here, more "electrics" ... ;)

 

We need to make a test fixture for 3-phase motors that will be run no load.  So the current draw will be a few amps per phase.

 

Input power is the standard industrial for our area:  460VAC (nominal), 60Hz, 3-phase.

 

The motors to be tested will be (all 60Hz 3-phase) 460V, 208V, and occasionally 575V for our friends in Canada.

 

None of us here are electrical "power" engineers.  So when I start looking generically for 3-phase transformers for this, I really don't find any with step-up+step-down taps.

 

I saw some references about running step-down (from e.g. 575V) "backwards" with appropriate derating.  Is that the way to go, as the current draws are modest?

 

As it is a one-off test rig, we'd rather be spending hundreds vs. thousands of dollars.

 

Any ideas?  TIA

You can put lipstick on a pig, but it is still a pig.

I've never met a pig I didn't like, as long as you have some salt and pepper.

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Why not use a three-phase inverter - maybe a Danfoss or something similar that has a wider voltage range than the less expensive models.  Even Allan Bradley, say, a 1305 or 1336  might meet all of your requirements.

 

Using a 3-pahse inverter, most of the instrumentation is built in - voltage, current HP, frequency, etc...

 

Just a thought...

 

You can avoid reality, for a while.  But you can't avoid the consequences of reality! - C.W. Livingston

Last Edited: Wed. Aug 19, 2015 - 09:29 PM
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Visit your local transformer manufacturer and have him wind you three multi tapped transformers. Or maybe your local motor rewinder has something you could rent/borrow.

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Letting the smoke out since 1978

 

 

 

 

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I once worked in a production setting and we had squarish boost transformers mounted on machines that either had a voltage drop or odd voltages. Google "boost transformer" to see if that is something you could use.