1. What is Single Phase Motor Power Calculation?

Definition: This calculator computes the real power (in kilowatts) consumed by a single-phase AC motor based on voltage, current, and power factor.

Purpose: It helps electricians and engineers determine the actual power consumption of single-phase motors for proper sizing and energy efficiency analysis.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( P_{kW} \) — Real power (kilowatts)
• \( V \) — Voltage (volts)
• \( I \) — Current (amps)
• \( PF \) — Power factor (unitless, 0-1)

Explanation: The product of voltage and current gives apparent power, which is then multiplied by the power factor to get real power, divided by 1000 to convert to kilowatts.

3. Importance of Power Factor

Details: Power factor represents the ratio of real power to apparent power. Motors typically have power factors between 0.7 and 0.95. Lower power factors indicate more reactive power and less efficient energy usage.

4. Using the Calculator

Tips: Enter the voltage in volts, current in amps, and power factor (default 0.85). All values must be > 0, and power factor must be ≤ 1.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical power factor for single-phase motors?
A: Most single-phase motors have power factors between 0.75 and 0.90 when fully loaded.

Q2: How do I measure voltage and current?
A: Use a multimeter to measure voltage across the motor terminals and current through one of the power wires.

Q3: Why convert to kilowatts?
A: Kilowatts are the standard unit for real power measurements and utility billing.

Q4: Does this include motor efficiency?
A: No, this calculates input power. For output power, multiply by the motor's efficiency.

Q5: What if I know horsepower instead of current?
A: First convert horsepower to watts (1 HP ≈ 746W), then divide by voltage and power factor to estimate current.