Why do NEMA Premium™ motors tend to run hotter and not last as long as standard motors that they replace?
A. A motor meeting “NEMA Premium” standards should run cooler, quieter and last longer. A consideration many times overlooked when replacing an existing motor, is that more efficient motors tend to be higher performing and may run a little faster. If the motor your replacing is running less than fully loaded and your process can utilize the new faster motor you’ll probably get the results and energy savings expected. However, motors applied to pumps, fans and blowers or variable torque loads, are many times affected by speed more profoundly than constant torque loads. For example: On a closed impeller centrifugal water pump, by replacing a 10 Hp, 1725 RPM with a motor at 1760 RPM you may now need 10.6 Hp. By making this change and disregarding the higher speed the motor may run hotter, use more energy and not last as long. Electric Motor Service Company may be able to help you by trimming the impeller or supplying appropriate sheaves and recommending other changes that will provide the
