Three Phase Motor Power Calculator

Three 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 Output (P):

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1. What is Three Phase Power?

Three-phase power is a common method of alternating current electric power generation, transmission, and distribution. It is widely used in industrial and commercial applications because it provides more power density than single-phase systems at the same amperage.

2. How Does the Calculator Work?

The calculator uses the three-phase power formula:

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

Where:

\( P \) — Power in watts (W)
\( V \) — Line-to-line voltage (V)
\( I \) — Current in amperes (A)
\( PF \) — Power factor (unitless, 0 to 1)
\( Eff \) — Efficiency (unitless, 0 to 1)
\( \sqrt{3} \) — Constant for three-phase systems (≈1.732)

Explanation: The formula accounts for all three phases in the system, with power factor and efficiency adjustments for real-world conditions.

3. Importance of Power Calculation

Details: Accurate power calculation is essential for sizing electrical equipment, determining energy consumption, calculating operating costs, and ensuring system safety and efficiency.

4. Using the Calculator

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

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between line-to-line and line-to-neutral voltage?
A: In three-phase systems, line-to-line voltage is √3 times the line-to-neutral voltage. This calculator uses line-to-line voltage.

Q2: Why include power factor and efficiency?
A: Power factor accounts for reactive power, while efficiency accounts for energy losses in the motor. Both reduce the actual usable power.

Q3: What are typical power factor values?
A: Induction motors typically have 0.85 PF at full load, dropping at partial loads. Synchronous motors can achieve 1.0 PF.

Q4: How does voltage variation affect power?
A: Power is directly proportional to voltage. A 10% voltage drop results in approximately 10% power reduction.

Q5: Can this be used for single-phase systems?
A: No, single-phase power is calculated as P = V × I × PF × Eff (without the √3 factor).