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AC Motor

AC Motor

AC Motor

(OP)
If I run an AC motor without a load, and the voltage drops current drops too.in what situation if the voltage drops ,current goes up. I guess when I have a load on the shaft and motor tries to compensate for that load right?
Please refer me to articles on this subject.

Thanks

RE: AC Motor

I think the condensed MG-1 standard (it's free) has an explanation of the impact of variations in voltage and frequency on motor performance.  

http://www.nema.org/stds/mg1condensed.cfm

A motor under load will draw more current when voltage goes down.  Think of it this way:  Power out of the motor needs to stay the same, so when voltage goes down, the current must increase to provide the same amount of output power.  

As a first approximation, you can model an ac motor as a constant kVA device for power flow analysis.  

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