3 Phase Motor Power Calculator with Current

3 Phase Motor Power Formula:

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

Line-to-Line Voltage (V):

volts

Current (I):

amperes

Power Factor (PF):

(0 to 1)

Efficiency (Eff):

(0 to 1)

Motor Power (P):

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1. What is 3-Phase Motor Power Calculation?

The 3-phase motor power calculation determines the real power consumed by a three-phase electric motor, accounting for voltage, current, power factor, and efficiency. This is essential for proper motor sizing, energy consumption analysis, and electrical system design.

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)
\( Eff \) — Motor efficiency (unitless, 0 to 1)

Explanation: The √3 factor accounts for the phase difference in three-phase systems. The formula calculates real power by considering both the power factor (ratio of real to apparent power) and motor efficiency.

3. Importance of Power Calculation

Details: Accurate power calculation helps in selecting proper motor sizes, determining electrical load requirements, calculating energy costs, and ensuring system protection devices are appropriately sized.

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 motor efficiency (typically 0.85-0.95 for standard 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 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: Why include power factor and efficiency?
A: Power factor accounts for phase difference between voltage and current. Efficiency accounts for energy lost as heat. Both are needed for accurate real power calculation.

Q3: What's a typical power factor for motors?
A: Induction motors typically have 0.85-0.90 PF at full load, lower at partial loads. Synchronous motors can achieve unity (1.0) PF.

Q4: How does motor size affect efficiency?
A: Larger motors (e.g., >100HP) typically have higher efficiencies (90-95%) than small motors (80-85%).

Q5: Can I use this for generator power calculation?
A: Yes, the same formula applies for 3-phase generators, using generator output voltage and current.