1. What is 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 motor selection, circuit protection, and wiring design.

2. How Does the Calculator Work?

The calculator uses the FLA formula for three-phase motors:

Where:

• \( Power \) — Motor power rating in kilowatts (kW)
• \( Voltage \) — Line voltage in volts (V)
• \( Power\ Factor \) — Ratio of real power to apparent power (0-1)
• \( Efficiency \) — Motor efficiency (0-1)

Explanation: The formula converts kW to watts (×1000), accounts for three-phase power (√3), and adjusts for power factor and motor efficiency losses.

3. Importance of FLA Calculation

Details: Knowing FLA is essential for proper circuit breaker sizing, conductor selection, overload protection, and ensuring motor performance within specifications.

4. Using the Calculator

Tips: Enter motor power in kW, line voltage in volts, power factor (typically 0.8-0.95), and efficiency (typically 0.85-0.95 for most motors). All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What's typical power factor for motors?
A: Induction motors typically have 0.85-0.90 PF at full load, lower at partial loads. Synchronous motors can achieve 1.0 or leading PF.

Q2: How does voltage affect FLA?
A: FLA is inversely proportional to voltage. A motor running at lower voltage will draw higher current to deliver the same power.

Q3: What's the difference between FLA and LRA?
A: FLA is full load current, while LRA (Locked Rotor Amps) is the initial current surge during startup, typically 5-7 times FLA.

Q4: Does this work for single-phase motors?
A: No, single-phase formula is different (FLA = (Power × 1000)/(Voltage × PF × Efficiency)).

Q5: Where can I find motor efficiency?
A: Check motor nameplate or manufacturer specs. Premium efficiency motors are typically 90-95% efficient.