another rpc question.

wow, we are talking about running an idler motor at 27.5% less voltage than nameplate.
i can't imagine a very long service life
we generally stay within 10% in my industry
the start up amps are sure to be huge to compensate for the 525v motor on single phase input.
but the delta hook up may help the current flow.
i'll be very interested to see how the experiment works out
 
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You should have no trouble at all running the 575V motor on 380V. The issue that you need to watch out for is that you do not exceed the FLA (current) as shown on the motor name plate. You certainly will not get 15kW - but to run this uncoupled and test it - not an issue. Motor repair shops do this all the time on much more expensive motors (for example 13.8kV motors run tested at 4160V and the reason is that 13.8kV test gear and equipment is very expensive). The motor will still run at close to the name plate speed (3 phase motor speed is determined by the # of poles, the line frequency and the "slip" of the transformer action - voltage and current are a lesser influence).

I have run 575V motors on 460V even with substantial load (talking 100HP motor loaded to 60HP) with no problem. Whether this will work for your RPC application depends on how much load you will have on the RPC. If you are only pulling 5HP, then you should be fine, and can easily confirm this with a current clamp.

Let us know how you make out. David

Sounds like this is quickly swirling down the drain - given that a the RPC motor/generator is running on only two legs to derive three phase power, so at best, you can expect maybe 57% of RPC motor loading (at rated voltage), and then on top of that reduce the voltage another 30%. If you were in the jungle somewhere and had nothing else and you absolutely needed a few turns of the lathe -- this could maybe work.
 
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