Expert ForumsMotors and Drives

Topic: Re: High efficiency motor ratings

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The input power to an ac motor is determined by volts, amps, efficiency and power factor. The formula for three-phase power is: watts = 1.732 x volts x amperes x power factor. Applying the formula, the reason for the higher current of the more efficient motor is that its power factor is lower than the standard motor. The premium motor power factor is 0.827 and the standard motor's is 0.895.