Question

An electric motor operates with an efficiency of 90 % the pump operated by the motor has an efficiency of 80% the overall efficiency of the system is

Answer 1

Most electric motors are designed to run at 50% to 100% of rated load. Maximum efficiency is usually near 75% of rated load. Thus, a 10-horsepower (hp) motor has an acceptable load range of 5 to 10 hp; peak efficiency is at 7.5 hp.