3 Phase Motor Power Calculator

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 three-phase electrical system. It's essential for sizing electrical equipment, determining energy consumption, and analyzing 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 (W)
\( V \) — Line-to-line voltage in volts (V)
\( I \) — Current in amperes (A)
\( PF \) — Power factor (unitless, between 0 and 1)

Explanation: The √3 factor accounts for the phase difference in three-phase systems. Power factor represents the ratio of real power to apparent power.

3. Importance of Power Factor

Details: Power factor is crucial in electrical systems. A low power factor (typically < 0.85) indicates poor utilization of electrical power and may result in additional charges from utility companies.

4. Using the Calculator

Tips: Enter line-to-line voltage in volts, current in amps, and power factor (typically between 0.8-1.0 for motors). All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between line and phase voltage?
A: In a 3-phase system, line voltage is between any two lines, while phase voltage is between any line and neutral. For star connections, line voltage = √3 × phase voltage.

Q2: What is a typical power factor for motors?
A: Induction motors typically have power factors between 0.85-0.90 at full load, decreasing at lower loads.

Q3: How does this differ from single-phase power calculation?
A: Single-phase power is P = V × I × PF (no √3 factor). Three-phase systems are more efficient for power transmission.

Q4: Can I use this for generator sizing?
A: Yes, this calculates real power which is essential for proper generator sizing, though you should also consider apparent power (VA).

Q5: What if I only know phase voltage?
A: For star-connected systems, multiply phase voltage by √3 to get line voltage. For delta connections, line and phase voltages are equal.