Paper: Pumping Unit Effect on Motor Efficiency

Electric motors are operated with cyclical loading on beam pumping units. However, motors are rated for steady loads. The performance of the motor changes when applied to a varying torque load, The motor efficiency, energy consumption and available torque are reduced, A method of calculating the effective ratings is presented. A comparison of operations on both conventional and unconventional pumping units is outlined, Economics of optimum motor sizing are discussed.