Power loss in the field and its percentage of total power
Mechanical Engineering
A 50-hp, 230-V shunt motor has a field resistance of 17.7 Q and operates at full load when the line current is 181 A at 1,350 r/min. To increase the speed of the motor to 1,600 r/min, a resistance of 5.3 Q is “cut in” via the field rheostat; the line current then increases to 190
A. Calculate
a. The power loss in the field and its percentage of the total power input for the 1,350 r/min speed.
b. The power losses in the field and the field rheostat for the 1,600 r/min speed.
c. The percent losses in the field and in the field rheostat at 1,600 r/min.
