Motors and blowers are frequently the single largest electricity consumers at a treatment plant or major pump station — which means the choices you make about how they're operated have a direct, measurable effect on your utility's operating budget. This guide covers motor efficiency standards, how variable frequency drives (VFDs) actually save energy (not just that they do), a deeper look at blower and compressor technology, and the basics of designing a reliable instrument air system.
Motor Efficiency and NEMA Premium
A motor's efficiency is the ratio of useful mechanical power output to electrical power input:
η=PinPout×100% The difference between input and output power isn't lost — it's converted to heat through winding resistance (I²R losses), core losses in the iron laminations, friction, and windage. Federal minimum efficiency standards fo