1. What is 3-Phase Motor FLA?

Full Load Amps (FLA) represents the current a 3-phase motor draws when operating at its rated power under full load. It's crucial for proper circuit breaker sizing, wire selection, and motor protection.

2. How Does the Calculator Work?

The calculator uses the 3-phase power formula:

Where:

• \( I \) — Full load current (amps)
• \( P \) — Motor power (watts)
• \( V \) — Line voltage (volts)
• \( PF \) — Power factor (0-1)
• \( \eta \) — Motor efficiency (0-1)

Explanation: The formula accounts for real power (P), apparent power (V×I), and motor efficiency to calculate the actual current draw.

3. Importance of FLA Calculation

Details: Accurate FLA calculation ensures proper sizing of motor starters, overload protection, and conductors, preventing equipment damage and fire hazards.

4. Using the Calculator

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

5. Frequently Asked Questions (FAQ)

Q1: What's typical power factor for motors?
A: Induction motors typically have 0.85 PF at full load, lower at partial loads. Synchronous motors can achieve 1.0 PF.

Q2: How does voltage affect FLA?
A: For constant power, lower voltage increases current proportionally (and vice versa).

Q3: What if I know horsepower instead of watts?
A: Convert HP to watts (1 HP = 746 watts) before using this calculator.

Q4: Why include efficiency?
A: Motors convert electrical to mechanical power. Efficiency accounts for losses (heat, friction).

Q5: How accurate is this calculation?
A: It provides theoretical FLA. Actual values may vary due to manufacturing tolerances, operating conditions.