About the Capacitor Selection Calculator

This calculator determines the appropriate running and starting capacitor values for single-phase utility pumps, such as submersible pumps, to ensure optimal performance and motor starting torque. It adheres to general electrical engineering practices for capacitor sizing in single-phase motors, aligned with IEEE Std 141-1993 (IEEE Recommended Practice for Electric Power Distribution for Industrial Plants).

The calculations are based on the following formulas:

• Power in Watts: P = Motor Power (HP) × 746 or P = Motor Power (kW) × 1000
• Current: I = P / (V × cos φ)
• Running Capacitor: C_run = I / (2 × π × f × V) × 10^6 (in µF)
• Starting Capacitor: C_start = C_run × 2.5 (approximate, rounded to standard values)

Where:

• P: Power in Watts
• I: Current in Amperes
• V: Supply Voltage in Volts
• cos φ: Power Factor
• f: Frequency in Hertz
• C_run: Running Capacitor in Microfarads (µF)
• C_start: Starting Capacitor in Microfarads (µF)