Chuck Yung
EASA Technical Support Specialist 

Occasionally, someone asks how much current a squirrel cage rotor bar carries. That’s an interesting question, and the answer depends on several factors. The rotor kVA* of a wound rotor motor is typically about 0.8 times the stator kVA. 

The rotor rated voltage is open circuit—a condition than cannot exist in a functional squirrel cage rotor— and the amps are at rated-load; the two don’t “coincide,” thus the 0.8 factor. For a squirrel-cage induction rotor, a multiplier of 0.96 is used because the magnetizing current comes from the stator rather than from the rotor. 

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