1. What is Full Load Amps (FLA)?

Full Load Amps (FLA) is the current a motor draws while operating at its rated load, voltage, and frequency. It's a crucial parameter for selecting proper wire sizes, circuit breakers, and overload protection devices.

2. How Does the Calculator Work?

The calculator uses the 3-phase power formula:

Where:

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

Explanation: The formula accounts for the three-phase power system (√3 factor) and adjusts for real power (PF) and energy losses (efficiency).

3. Importance of FLA Calculation

Details: Accurate FLA calculation is essential for proper motor protection, preventing overheating, and ensuring electrical system safety. It helps in selecting appropriate circuit breakers, fuses, and overload relays.

4. Using the Calculator

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

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between FLA and LRA?
A: FLA is full load amps during normal operation, while LRA (locked rotor amps) is the current during startup (typically 5-7 times FLA).

Q2: How does voltage affect FLA?
A: FLA is inversely proportional to voltage. Lower voltage increases current draw for the same power output.

Q3: What's a typical power factor for motors?
A: Induction motors typically have 0.8-0.9 PF at full load, lower at partial loads. Synchronous motors can achieve 1.0 PF.

Q4: How accurate is this calculation?
A: It provides theoretical FLA. Actual values may vary due to manufacturing tolerances, operating conditions, and power quality.

Q5: Can I use this for single-phase motors?
A: No, single-phase motors use a different formula (I = P / (V × PF × η)).