Calculate motor efficiency and the annual cost of its losses.
Motor efficiency looks high in percentage terms but the losses are continuous. Over 6,000 hours a year even a 1.5 kW loss costs more than the motor, which is why efficiency classes are regulated. The lifetime energy cost of an industrial motor is typically 50 to 100 times its purchase price, so two points of efficiency dominate the buying decision.
Motor Efficiency
η = output ÷ input × 100
η = output ÷ input × 100 Motor efficiency looks high in percentage terms but the losses are continuous. Over 6,000 hours a year even a 1.5 kW loss costs more than the motor, which is why efficiency classes are regulated.
The lifetime energy cost of an industrial motor is typically 50 to 100 times its purchase price, so two points of efficiency dominate the buying decision.
This calculator takes 4 inputs: Shaft output power, Electrical input power, Operating hours per year, Energy price per kWh. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.