Motor Efficiency Calculator
Energy auditing, comparing standard vs premium efficiency motors for ROI. Calculates percentage energy efficiency comparing mechanical shaft output power to input electrical power.
Step-by-Step Derivation ▼ Show Steps
Calculations adhere to standard electrical engineering physics and National Electrical Code (NFPA 70) regulations.
Engineering Principles & Calculations
This calculator uses the exact mathematical relationships between Output Horsepower (HP), Input Voltage (V), Input Current (A), Power Factor (PF) to determine Efficiency Percentage (η %), Waste Heat Dissipation (Watts & BTU/hr), IE Standard Class Rating (IE1, IE2, IE3, IE4). In practical installations, factors such as ambient raceway temperature, harmonic distortion, duty cycle continuous operation, and conductor impedance must be accounted for by a certified electrician.
Calculates percentage energy efficiency comparing mechanical shaft output power to input electrical power.
Typical Application & Industry Guidelines
Energy auditing, comparing standard vs premium efficiency motors for ROI.
Motor Efficiency Calculator Benchmark Lookup Table
| Motor HP | NEMA Energy Efficient | NEMA Premium Efficiency | Annual Dollar Savings @ .15/kWh |
|---|---|---|---|
| 5 HP | 87.5% | 89.5% | / year |
| 10 HP | 89.5% | 91.7% | / year |
| 25 HP | 92.4% | 93.6% | / year |
| 50 HP | 93.0% | 94.5% | / year |
| 100 HP | 94.1% | 95.4% | ,380 / year |