kW to Amps Three Phase Formula

Three Phase Current Formula:

\[ I = \frac{P_{kW} \times 1000}{V \times PF \times \sqrt{3}} \]

Current (I): amps

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1. What is kW to Amps Three Phase Calculator?

Definition: This calculator converts electrical power in kilowatts (kW) to current in amps (A) for three-phase AC systems.

Purpose: It helps electricians, engineers, and technicians determine the current draw of three-phase electrical equipment.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ I = \frac{P_{kW} \times 1000}{V \times PF \times \sqrt{3}} \]

Where:

\( I \) — Current in amps (A)
\( P_{kW} \) — Power in kilowatts (kW)
\( V \) — Line-to-line voltage (V)
\( PF \) — Power factor (unitless, between 0 and 1)

Explanation: The formula converts kW to watts (×1000), then divides by the product of voltage, power factor, and √3 (approximately 1.732) for three-phase systems.

3. Importance of Three Phase Current Calculation

Details: Accurate current calculation ensures proper wire sizing, circuit breaker selection, and prevents equipment damage from overload.

4. Using the Calculator

Tips: Enter the power in kW, line voltage (default 480V), and power factor (default 0.85). All values must be > 0, with PF between 0.01 and 1.

5. Frequently Asked Questions (FAQ)

Q1: Why is √3 used in the formula?
A: √3 accounts for the phase difference in three-phase systems, converting between line-to-line and phase quantities.

Q2: What's a typical power factor value?
A: Motors typically have PF of 0.85, resistive loads 1.0, and poor power factor loads may be 0.6 or lower.

Q3: Does this work for single-phase systems?
A: No, for single-phase use: I = P × 1000 / (V × PF) without the √3 factor.

Q4: What voltage should I use?
A: Use the line-to-line voltage: 208V, 480V, or 600V are common in North America.

Q5: How do I find the power factor?
A: Check equipment specifications or use a power factor meter. Estimate 0.85 if unknown.