Permanent Magnet AC (PMAC) Motors

Lab testing was conducted to evaluate the efficiency at various loads for PMAC motors at the 3 and 5 HP sizes compared with Premium Efficiency Induction Motor (PEIM) technology. Lab testing found efficiency increases to be between 2% and 24% for the 3 HP motor and 4% to 24% for the 5 HP motor, linearly increasing with increased motor speed. The PMAC motors tested in this study all required Variable Frequency Drives (VFD) to be bundled with their products. While these motors offer significant efficiency increases over PEIM products, it was found that cost effectiveness may suffer due to the additional costs associated with the VFD requirement. Additional study for motors in various sizes and configurations that might offer efficient alternatives is suggested.