1. What is a 3 Phase Ampere Calculator?

Definition: This calculator determines the current (amperage) in a three-phase electrical system based on power, voltage, and power factor.

Purpose: It helps electricians, engineers, and technicians properly size electrical components and ensure safe system operation.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( I \) — Current in amperes (A)
• \( P_{kW} \) — Power in kilowatts (kW)
• \( V \) — Line-to-line voltage (V)
• \( PF \) — Power factor (unitless, between 0 and 1)

Explanation: The formula converts kW to watts (×1000), then divides by the product of voltage, power factor, and √3 (approximately 1.732) which accounts for the three-phase configuration.

3. Importance of 3 Phase Current Calculation

Details: Accurate current calculation is critical for selecting proper wire sizes, circuit breakers, and other electrical components to prevent overheating and ensure system safety.

4. Using the Calculator

Tips: Enter the power in kW, line-to-line voltage (default 400V), and power factor (default 0.8). All values must be > 0, with PF between 0.01 and 1.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical power factor value?
A: For motors, PF is typically 0.8-0.9. Resistive loads have PF=1. Always check equipment specifications.

Q2: Why use line-to-line voltage?
A: In 3-phase systems, this is the standard measurement between any two phases (often 400V, 480V, etc.).

Q3: What if I know power in HP instead of kW?
A: First convert HP to kW (1 HP ≈ 0.746 kW) before using this calculator.

Q4: Does this work for single-phase systems?
A: No, use I = P×1000/(V×PF) for single-phase (omit the √3 factor).

Q5: How accurate is this calculation?
A: It provides theoretical current. Actual current may vary due to efficiency losses, harmonics, etc.