1. What is the Three-Phase Amp Draw Calculation?

The Three-Phase Amp Draw calculation determines the current (in amperes) drawn by a three-phase electrical system based on power, voltage, and power factor. This is essential for electrical system design, load balancing, and equipment selection.

2. How Does the Calculator Work?

The calculator uses the three-phase amp draw formula:

Where:

• \( Power \) — Power in kilowatts (kW)
• \( Voltage \) — Line-to-line voltage in volts (V)
• \( PF \) — Power Factor (dimensionless, between 0 and 1)
• \( \sqrt{3} \) — Mathematical constant (approximately 1.732)

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

3. Importance of Three-Phase Amp Calculation

Details: Accurate amp draw calculation is crucial for proper circuit breaker sizing, wire gauge selection, transformer specification, and ensuring electrical system safety and efficiency.

4. Using the Calculator

Tips: Enter power in kilowatts, voltage in volts, and power factor (typically between 0.8-1.0). All values must be valid (power > 0, voltage > 0, 0 < PF ≤ 1).

5. Frequently Asked Questions (FAQ)

Q1: Why is the square root of 3 used in three-phase calculations?
A: The square root of 3 (approximately 1.732) accounts for the phase relationship between line-to-line and line-to-neutral voltages in balanced three-phase systems.

Q2: What is power factor and why is it important?
A: Power factor represents the ratio of real power to apparent power. It's important because lower power factors result in higher current draw for the same real power.

Q3: When should I use this calculation?
A: Use this calculation when designing or analyzing three-phase electrical systems, selecting circuit protection devices, or determining conductor sizes.

Q4: Are there limitations to this equation?
A: This equation assumes a balanced three-phase system with sinusoidal waveforms. It may not be accurate for unbalanced systems or systems with significant harmonic distortion.

Q5: How does voltage affect amp draw?
A: Higher voltages result in lower amp draw for the same power, which is why high-voltage transmission is used for long-distance power distribution.