Motor Drive System Homework

Calculate the simple paybacks of replacing a failed 75%-loaded, 15-hp, standard-efficiency motor with an energy-efficient motor rather than rewinding it, if the motor runs 2,000, 5,000 and 8,000 hours per year. A 20-hp motor runs 5,000 hours per year, produces 4 hp of shaft work, and operates at 50% efficiency with a power factor of 0.60 kW/kVA. ................
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