1. What is a Three Phase Motor Power Calculator?

Definition: This calculator estimates the power consumption of a three-phase electric motor based on voltage, current, and power factor.

Purpose: It helps electrical engineers, technicians, and maintenance personnel determine motor power requirements and energy consumption.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( P_{kW} \) — Power in kilowatts (kW)
• \( V \) — Line voltage (volts)
• \( I \) — Line current (amps)
• \( PF \) — Power factor (0 to 1)
• \( \sqrt{3} \) — Constant for three-phase systems (≈1.732)

Explanation: The formula accounts for all three phases in the system and converts the result to kilowatts.

3. Importance of Three Phase Power Calculation

Details: Accurate power calculation ensures proper motor sizing, circuit protection, and energy efficiency analysis.

4. Using the Calculator

Tips: Enter the line voltage, line current, and power factor (default 0.85). All values must be > 0, with PF between 0 and 1.

5. Frequently Asked Questions (FAQ)

Q1: What is power factor?
A: Power factor is the ratio of real power to apparent power, representing how effectively current is converted to useful work (typically 0.8-0.95 for motors).

Q2: Why use √3 in the calculation?
A: The √3 accounts for the phase difference in three-phase systems, converting line-to-line measurements to per-phase values.

Q3: How do I measure line current?
A: Use a clamp meter on any one of the three phase conductors while the motor is running under load.

Q4: What's typical voltage for industrial motors?
A: Common voltages include 208V, 230V, 460V, or 575V, depending on regional standards and motor size.

Q5: Can I calculate horsepower from this?
A: Yes, 1 HP ≈ 0.746 kW, so divide the kW result by 0.746 to get horsepower.