3 Phase Motor Power Calculator with Current

3-Phase Power Formula:

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

Power (P):

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1. What is 3-Phase Power Calculation?

The 3-phase power calculation determines the real power (in watts) consumed by a 3-phase motor or electrical system using voltage, current, and power factor. It's essential for sizing electrical components and assessing motor performance.

2. How Does the Calculator Work?

The calculator uses the 3-phase power formula:

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

Where:

\( P \) — Real power in watts
\( V \) — Line-to-line voltage in volts
\( I \) — Current in amps
\( PF \) — Power factor (unitless, between 0-1)
\( \sqrt{3} \) — Constant for 3-phase systems (≈1.732)

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

3. Importance of Power Calculation

Details: Accurate power calculation is crucial for proper motor selection, electrical system design, energy efficiency assessment, and circuit protection sizing.

4. Using the Calculator

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

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between line and phase voltage?
A: In 3-phase systems, line voltage is between any two lines, while phase voltage is between any line and neutral. For delta connections, they're equal; for wye, line voltage is √3 × phase voltage.

Q2: What is a typical power factor for motors?
A: Induction motors typically have power factors between 0.8-0.95 when fully loaded. It decreases with lighter loads.

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

Q4: Why is the power factor important?
A: It indicates how effectively current is being converted to useful work. Lower PF means more current is needed for the same real power.

Q5: How does this relate to motor horsepower?
A: To convert watts to HP, divide by 746 (1 HP = 746 watts). Remember this gives electrical input power, not necessarily mechanical output.