Motor FLA Chart: Full Load Amps by HP

What Is Motor FLA (Full Load Amps)?

Motor FLA (Full Load Amps) is the amount of current an electric motor draws when operating at its rated full-load torque and horsepower at rated voltage and frequency. This value is specified on the motor nameplate and is essential for proper electrical system design.

The FLA rating is used as the baseline for:

Branch-circuit conductor sizing — NEC 430.22 requires conductors rated at 125% of FLA
Overcurrent protection — fuses and circuit breakers sized per NEC 430.52
Motor starter selection — NEMA starter sizes based on FLA and voltage
Overload relay sizing — typically set at 115–125% of FLA
Voltage drop calculations — ensuring adequate voltage at motor terminals

                    💡 Important: Always use the nameplate FLA for final equipment sizing. The values in this chart represent typical NEMA-rated motors and may vary slightly by manufacturer, efficiency class, and design type.
                

Single-Phase Motor FLA Chart

Single-phase motors are commonly used in residential HVAC systems, small pumps, compressors, and fans. The following table shows typical FLA values at 230V single-phase for standard NEMA motors:

HP	kW	FLA at 230V	Min Wire (125%)	Typical Application
1/4	0.19	3.1 A	3.9 A	Small fans, blowers
1/3	0.25	4.1 A	5.1 A	Condensate pumps
1/2	0.37	5.6 A	7.0 A	Exhaust fans, small pumps
3/4	0.56	7.1 A	8.9 A	Booster pumps
1	0.75	10.0 A	12.5 A	AC compressors (small)
1-1/2	1.12	13.2 A	16.5 A	AC compressors
2	1.49	16.0 A	20.0 A	AC compressors, pumps
3	2.24	24.0 A	30.0 A	Large compressors
5	3.73	34.0 A	42.5 A	Commercial equipment

Values at 230V for NEMA Design B motors. At 115V, multiply FLA by approximately 2.

Three-Phase Motor FLA Chart

Three-phase motors are the standard for commercial and industrial HVAC equipment due to their higher efficiency and lower current draw per conductor. The following table shows typical FLA values at 460V three-phase:

HP	kW	FLA at 460V	Min Wire (125%)	Typical Application
1/2	0.37	1.7 A	2.1 A	Small fans
3/4	0.56	2.4 A	3.0 A	Ventilation fans
1	0.75	3.1 A	3.9 A	Supply fans, pumps
1-1/2	1.12	4.7 A	5.9 A	AHU fans
2	1.49	6.2 A	7.8 A	Air handlers
3	2.24	9.2 A	11.5 A	Compressor motors
5	3.73	15.2 A	19.0 A	Chiller compressors
7-1/2	5.59	22.0 A	27.5 A	Commercial compressors
10	7.46	28.0 A	35.0 A	Industrial equipment

Values at 460V for NEMA Design B motors. At 230V three-phase, multiply FLA by approximately 2.

FLA vs LRA vs RLA: Understanding Motor Current Terms

Motor current ratings can be confusing because multiple abbreviations are used. Here's a clear breakdown:

Term	Full Name	Meaning	Typical Magnitude
FLA	Full Load Amps	Current at rated full load	1× (baseline)
RLA	Rated Load Amps	Compressor rated current (AHRI)	≈ FLA
LRA	Locked Rotor Amps	Starting current at standstill	5–8× FLA
FLC	Full Load Current	Same as FLA (NEC terminology)	1× FLA

Why does this matter? When selecting circuit breakers or fuses, you must account for LRA to prevent nuisance tripping on motor startup. The NEC provides specific tables (Table 430.251, 430.248, 430.250) for FLC values used in conductor and overcurrent protection sizing.

How to Use the Motor FLA Chart

Follow these steps to properly use the FLA chart for electrical design:

Step 1: Identify Motor Specifications

Determine your motor's HP rating, voltage, and phase type (single-phase or three-phase). Check the equipment nameplate or manufacturer data sheets.

Step 2: Find the FLA Value

Locate the intersection of your motor's HP and voltage in the appropriate table above. For motors at voltages not shown, use the scaling factors noted.

Step 3: Apply NEC 430.22 Multiplier

Multiply the FLA by 1.25 (125%) to determine the minimum conductor ampacity. Select wire from NEC Table 310.16 that meets or exceeds this value.

Step 4: Size Overcurrent Protection

Per NEC 430.52, use time-delay fuses (175% FLA) or inverse-time breakers (250% FLA) for branch-circuit protection. Overload relays provide the primary overload protection at 115–125% FLA.

                    ⚠️ Safety Note: The FLA chart values are for standard motors. Always verify with the actual motor nameplate. Motors with high efficiency ratings, special designs, or non-standard speeds may have different FLA values.
                

Factors That Affect Motor FLA

Several factors can cause the actual motor current to differ from the chart values:

Voltage variation: Low voltage increases current draw proportionally. A 5% voltage drop can increase current by 5–10%.
Motor efficiency: Higher efficiency motors (NEMA Premium) may have slightly different FLA ratings due to optimized winding designs.
Motor speed: The chart assumes standard 2-pole (3600 RPM) and 4-pole (1800 RPM) motors. Slower speed motors (6-pole, 8-pole) draw more current.
Ambient temperature: Motors in high-temperature environments may be derated, affecting allowable continuous current.
Service factor: Motors with a service factor of 1.15 can operate at 115% of rated load, but NEC conductor sizing still uses nameplate FLA.
Load type: Constant-torque loads (conveyors, compressors) maintain FLA throughout the speed range, while variable-torque loads (fans, pumps) draw less at reduced speeds.

NEC Requirements for Motor Circuits

The National Electrical Code (NEC) has specific requirements for motor circuits that reference FLA values:

NEC 430.22 — Branch-Circuit Conductors

Conductors supplying a single motor must have an ampacity of not less than 125% of the motor FLC (full-load current) as given in NEC Tables 430.248 (single-phase) and 430.250 (three-phase).

NEC 430.32 — Overload Protection

Overload devices must be sized at 115% of motor FLC for motors with a service factor of 1.15 or greater, or 125% of FLC for motors with a temperature rise not over 40°C.

NEC 430.52 — Branch-Circuit Short-Circuit and Ground-Fault Protection

Maximum ratings for fuses and circuit breakers based on motor type and starting characteristics:

Non-time-delay fuses: 300% of FLC
Time-delay fuses: 175% of FLC
Inverse-time circuit breakers: 250% of FLC

Need to Calculate Motor Current?

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Frequently Asked Questions

FLA stands for Full Load Amps, which is the amount of current a motor draws when operating at its rated full-load torque and horsepower at rated voltage and frequency. It is the baseline current value used for sizing conductors, overcurrent protection, and motor starters per NEC requirements.

FLA (Full Load Amps) is the rated current at full load conditions for a motor. RLA (Rated Load Amps) is commonly used for hermetic compressors and represents the current draw under specific rated conditions. FLA is the standard term for general-purpose motors, while RLA is specific to refrigeration and HVAC compressor applications.

Three-phase motors distribute power across three conductors with 120° phase separation, providing more efficient power delivery. For the same horsepower rating, a three-phase motor draws significantly less current per conductor because the total power is split across three phases. This results in smaller wire sizes, lower voltage drop, and more efficient operation.

Per NEC 430.22, you must size motor branch-circuit conductors at 125% of the motor FLA. Find your motor's FLA from the chart based on HP and voltage, then multiply by 1.25. Select a wire size from NEC Table 310.16 that has an ampacity equal to or greater than the calculated value.

Yes, motor FLA is inversely proportional to voltage. A motor connected to a lower voltage will draw more current to produce the same power output. For example, a 1HP single-phase motor draws approximately 10A at 120V but only about 5A at 240V. Always check the motor nameplate for the exact rated FLA at your specific voltage.

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