Power Calculation 3 Phase Motor Wiring Diagram

3-Phase Power Formula:

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

Voltage (V):

Current (I):

Power Factor (PF):

(0-1)

Efficiency (Eff):

(0-1)

Power (P):

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1. What is 3-Phase Power Calculation?

The 3-phase power calculation determines the real power consumed by a three-phase motor or electrical system. It accounts for line-to-line voltage, current, power factor, and efficiency to provide accurate power measurement.

2. How Does the Calculator Work?

The calculator uses the 3-phase power formula:

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

Where:

\( P \) — Real power in watts (W)
\( V \) — Line-to-line voltage in volts (V)
\( I \) — Current in amperes (A)
\( PF \) — Power factor (unitless, 0 to 1)
\( Eff \) — Efficiency (unitless, 0 to 1)

Explanation: The square root of 3 (≈1.732) accounts for the phase difference in three-phase systems. The formula calculates real power by considering both the power factor and motor efficiency.

3. Importance of Power Calculation

Details: Accurate power calculation is essential for proper motor sizing, electrical system design, energy consumption analysis, and determining operational costs.

4. Using the Calculator

Tips: Enter line-to-line voltage in volts, current in amps, power factor (typically 0.8-0.95 for motors), and efficiency (typically 0.85-0.95 for motors). All values must be positive.

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 one phase and neutral. The calculator uses line-to-line voltage.

Q2: Why include efficiency in the calculation?
A: Motors convert electrical power to mechanical power with some losses. Efficiency accounts for these losses to determine actual electrical power input.

Q3: What is a typical power factor for motors?
A: Induction motors typically have power factors between 0.8-0.9 at full load, lower at partial loads. Synchronous motors can achieve unity (1.0) power factor.

Q4: How does this differ from single-phase power calculation?
A: Single-phase uses P = V × I × PF, without the √3 factor or efficiency (unless specifically calculating input power).

Q5: Can I use this for generator output calculation?
A: Yes, the same formula applies for generator output power calculation, using generator output voltage and current.