How To Calculate Amps From Watts Three Phase

Three Phase Power Formula:

\[ I = \frac{W}{V \times \sqrt{3} \times PF} \]

Current (I):

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is the Three Phase Power Formula?

The three phase power formula calculates electrical current (amps) from power (watts) in a three phase AC system. It accounts for the phase relationship between voltage and current through the power factor, and the three-phase configuration through the √3 factor.

2. How Does the Calculator Work?

The calculator uses the three phase power formula:

\[ I = \frac{W}{V \times \sqrt{3} \times PF} \]

Where:

\( I \) — Current in amperes (amps)
\( W \) — Power in watts
\( V \) — Voltage in volts
\( PF \) — Power factor (dimensionless, 0-1)
\( \sqrt{3} \) — Approximately 1.732 (dimensionless)

Explanation: The formula accounts for the three-phase power system where the total power is distributed across three phases, requiring the √3 factor for accurate current calculation.

3. Importance of Three Phase Current Calculation

Details: Accurate current calculation is crucial for proper electrical system design, circuit protection, equipment sizing, and energy efficiency in three-phase industrial and commercial applications.

4. Using the Calculator

Tips: Enter power in watts, voltage in volts, and power factor (0-1). All values must be valid (watts > 0, volts > 0, 0 < PF ≤ 1).

5. Frequently Asked Questions (FAQ)

Q1: Why is √3 used in three-phase calculations?
A: √3 accounts for the phase difference between the three phases in a balanced three-phase system, converting line-to-line voltage to phase voltage.

Q2: What is power factor and why is it important?
A: Power factor represents the ratio of real power to apparent power. It's crucial because it affects the actual current drawn and system efficiency.

Q3: When is this formula applicable?
A: This formula applies to balanced three-phase AC systems with sinusoidal waveforms. It's commonly used in industrial and commercial electrical systems.

Q4: What are typical power factor values?
A: Power factor typically ranges from 0.7 to 1.0. Industrial motors often have PF around 0.8-0.9, while purely resistive loads have PF = 1.0.

Q5: How does this differ from single-phase calculation?
A: Single-phase formula is I = W/(V × PF) without the √3 factor. Three-phase systems are more efficient for power distribution.