Motor Efficiency
Definition
The ratio of mechanical output power to electrical input power, expressed as a percentage. Losses include copper (I²R), iron (core), mechanical (friction), and stray load losses.
Practical Note
Standard motors: 85-90%, High efficiency (IE2): 90-93%, Premium (IE3): 92-95%, Super premium (IE4): 94-97%. Higher efficiency costs more but saves energy over motor lifetime.