Question 2.8: Power-Factor-Correcting Capacitor for a Motor What size capa......

Renewable and Efficient Electric Power Systems [1073600]

Power-Factor-Correcting Capacitor for a Motor What size capacitor would be needed to correct the power factor of the 230-V, 60-Hz, 5-hp motor in Example 2.6?

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The capacitor must provide 4.40 kVAR of capacitive reactance to correct for the motor’s 4.40 kVAR of inductive reactance. Since this is a 230-V motor operating at 60 Hz, (2.46) indicates that the capacitor should be

C \ = \ \frac{VARs}{\omega V^{2}} \ = \ \frac{4400}{2 \pi \ \times \ 60 \ \times \ \left(230\right)^{2}} \ = \ 0.000221 \ F \ = \ 221 \ \mu F

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