kW to Amps 3 Phase Calculator by Tons of Concrete

3 Phase Current Formula:

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

Current (I): amps

Definition: This calculator converts kilowatts (kW) to amperes (amps) for three-phase electrical systems.

Purpose: It helps electricians, engineers, and technicians determine the current draw of three-phase equipment based on power rating.

The calculator uses the formula:

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

Where:

Explanation: The formula accounts for three-phase power characteristics including the √3 factor and power factor.

Details: Accurate current calculation ensures proper wire sizing, circuit protection, and equipment compatibility in three-phase systems.

Tips: Enter the power in kW, line voltage (default 400V), and power factor (default 0.8). All values must be > 0 (PF between 0.01 and 1).

Q1: Why is √3 used in the formula?
A: The √3 factor accounts for the phase difference in three-phase systems (120° between phases).

Q2: What's a typical power factor value?

A: Motors typically have PF of 0.8-0.9, while resistive loads have PF of 1.0.

Q3: Is this for line-to-line or line-to-neutral voltage?
A: The formula uses line-to-line voltage (common in three-phase systems).

Q4: How do I find the power factor?
A: Check equipment specifications or use a power factor meter. For unknown values, 0.8 is a safe estimate.

Q5: Does this work for single-phase systems?
A: No, use a different formula (I = P × 1000 / (V × PF)) for single-phase calculations.