1. What is Full Load Amps (FLA)?

Full Load Amps (FLA) is the current a motor draws while operating at its rated horsepower and voltage. It's used for sizing motor protection devices, conductors, and other electrical components according to NEC standards.

2. How Does the Calculator Work?

The calculator uses values from NEC Table 430.250:

Where:

• FLA — Full load current in amperes
• Values are based on motor horsepower, voltage, and phase
• Table values assume Design B motors at 60Hz

Explanation: The NEC tables provide standardized values that account for typical motor characteristics and efficiency.

3. Importance of FLA Calculation

Details: Correct FLA determination is crucial for proper circuit protection (fuses, breakers), conductor sizing, and overload protection to prevent motor damage and ensure safe operation.

4. Using the Calculator

Tips: Enter motor horsepower, voltage, select phase and motor type. The calculator will provide the NEC table value with adjustments for motor type.

5. Frequently Asked Questions (FAQ)

Q1: Why use NEC tables instead of nameplate FLA?
A: NEC tables provide standardized values for circuit design, while nameplate values are specific to that motor. NEC requires using table values for conductor sizing.

Q2: What's the difference between FLA and LRA?
A: FLA is full load current during normal operation. LRA (Locked Rotor Amps) is the current during startup (typically 5-7 times FLA).

Q3: How does voltage affect FLA?
A: Higher voltage means lower current for the same power. A 10HP motor at 230V draws more current than at 460V.

Q4: What if my motor isn't listed in the tables?
A: For motors not listed, use the next higher HP value or consult the manufacturer's data.

Q5: How do I account for different service factors?
A: Service factor affects motor capacity but not the NEC table FLA values used for circuit design.