1. What is 3 Phase Motor Current?

The 3-phase motor current is the amount of electrical current required by a three-phase motor to produce a certain mechanical power output. It's essential for proper motor sizing, circuit protection, and electrical system design.

2. How Does the Calculator Work?

The calculator uses the 3-phase current formula:

Where:

• \( I \) — Current in amps
• \( P \) — Power in watts
• \( V \) — Line voltage in volts
• \( PF \) — Power factor (0.1-1.0)
• \( \eta \) — Motor efficiency (0.1-1.0)

Explanation: The formula accounts for the three-phase power system (√3 factor) and the motor's power factor and efficiency.

3. Importance of Current Calculation

Details: Accurate current calculation is crucial for selecting proper wire sizes, circuit breakers, overload protection, and ensuring the motor operates within its design parameters.

4. Using the Calculator

Tips: Enter power in watts, voltage in volts, power factor (typically 0.8-0.95 for motors), and motor efficiency (typically 0.85-0.95). All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between line and phase voltage?
A: Line voltage is between any two phases, while phase voltage is between a phase and neutral. In balanced systems, line voltage = √3 × phase voltage.

Q2: How do I find my motor's power factor?
A: Check motor specifications or nameplate. Typical values are 0.8-0.95 for AC motors at full load.

Q3: What if my motor power is in horsepower?
A: Convert horsepower to watts (1 HP ≈ 746 watts) before using the calculator.

Q4: Why does efficiency affect current?
A: Less efficient motors require more input current to produce the same output power.

Q5: Is this calculation valid for single-phase motors?
A: No, single-phase motors use a different formula without the √3 factor.