Calculate 3 Phase kW from Amps and Current

3-Phase Power Formula:

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

Power Output:

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is 3-Phase Power Calculation?

The 3-phase power calculation determines the real power (kW) in a three-phase electrical system using voltage, current, and power factor. It's essential for sizing electrical equipment and assessing power consumption in industrial and commercial settings.

2. How Does the Calculator Work?

The calculator uses the 3-phase power formula:

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

Where:

\( V \) — Line-to-line voltage (volts)
\( I \) — Current (amperes)
\( PF \) — Power factor (unitless, 0 to 1)
\( \sqrt{3} \) — Constant for 3-phase systems (≈1.732)
1000 — Conversion factor from watts to kilowatts

Explanation: The formula accounts for the phase relationship in 3-phase systems and the power factor which represents the ratio of real power to apparent power.

3. Importance of Power Factor

Details: Power factor (PF) indicates how effectively electrical power is converted to useful work. A PF of 1 means all power is real power (kW), while lower PF values indicate reactive power components.

4. Using the Calculator

Tips: Enter line-to-line voltage in volts, current in amperes, and power factor (typically 0.8-0.95 for motors). All values must be positive with PF between 0 and 1.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between line-to-line and line-to-neutral voltage?
A: In 3-phase systems, line-to-line voltage is between any two phases, while line-to-neutral is between a phase and neutral. The calculator uses line-to-line voltage.

Q2: What is a typical power factor value?
A: Induction motors typically have 0.8-0.9 PF at full load. Resistive loads have PF=1. The default 0.8 is a common assumption for motor loads.

Q3: Why is √3 used in the formula?
A: The √3 accounts for the 120° phase shift between the three phases in a balanced 3-phase system.

Q4: Can this be used for single-phase calculations?
A: No, single-phase power uses P = V × I × PF (without the √3 factor).

Q5: How does this relate to kVA (apparent power)?
A: kVA = (√3 × V × I)/1000. Real power (kW) = kVA × PF. The calculator gives real power in kW.