1. What is 3-Phase Voltage Calculation?

The 3-phase voltage calculation determines the required voltage for a three-phase AC motor based on its power rating, full load amperage, power factor, and efficiency. This is essential for proper motor selection and electrical system design.

2. How Does the Calculator Work?

The calculator uses the 3-phase voltage formula:

Where:

• \( Power \) — Motor power rating in kilowatts (kW)
• \( FLA \) — Full load amperage in amps (A)
• \( Power\ Factor \) — Ratio of real power to apparent power (typically 0.8-0.95)
• \( Efficiency \) — Motor efficiency as a decimal (typically 0.85-0.95)
• \( \sqrt{3} \) — Constant for 3-phase systems (approximately 1.732)

Explanation: The formula converts power from kW to watts (×1000), then divides by the product of current, power factor, efficiency, and the square root of 3 for three-phase systems.

3. Importance of Voltage Calculation

Details: Accurate voltage calculation ensures proper motor operation, prevents overheating, and helps select correct electrical components like circuit breakers and wiring.

4. Using the Calculator

Tips: Enter motor power in kW, full load amperage in amps, power factor (typically 0.85), and efficiency (typically 0.90). All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical power factor for motors?
A: Most AC motors have power factors between 0.8 and 0.95, with 0.85 being a common default value.

Q2: How do I find my motor's efficiency?
A: Check motor nameplate or manufacturer specifications. Standard efficiency motors are typically 85-95% efficient.

Q3: Why multiply power by 1000?
A: The formula converts kilowatts (input) to watts (1000 watts = 1 kW) for consistent units in the calculation.

Q4: What if I only know horsepower?
A: Convert horsepower to kW (1 HP ≈ 0.746 kW) before using the calculator.

Q5: Does this work for single-phase motors?
A: No, this is specifically for three-phase motors. Single-phase calculations use a different formula.