1. What is Three Phase Motor Power Calculation?

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

Purpose: It helps electrical engineers, technicians, and maintenance personnel determine motor power consumption for energy monitoring and system design.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

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

Explanation: The formula accounts for all three phases in the system and converts the result to kilowatts by dividing by 1000.

3. Importance of Motor Power Calculation

Details: Accurate power calculation ensures proper sizing of electrical components, energy efficiency monitoring, and cost analysis for industrial operations.

4. Using the Calculator

Tips: Enter the line-to-line voltage in volts, line current in amps, 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: Should I use line or phase voltage?
A: Use line-to-line voltage (typically 208V, 400V, 480V, etc. depending on your system).

Q3: What's a typical power factor for motors?
A: Most three-phase induction motors have a PF of 0.85 at full load, but this varies with motor size and load conditions.

Q4: How does this differ from single-phase calculation?
A: Single-phase uses P=VI×PF without the √3 factor, as it only considers one phase.

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