Home
Back
Full Load Current Equation:
Where time is not directly in the equation but affects the current measurement over time.
| From: | To: |
Full Load Current (FLC) is the current drawn by an electric motor when operating at its rated power and voltage. It's an important parameter for sizing circuit protection devices and conductors.
The calculator uses the basic electrical power equation:
Where:
Time Factor: While time isn't in the FLC equation directly, the calculator also computes energy consumption over time (watt-hours) to show how current affects power usage over time.
Details: Knowing the full load current is essential for proper motor protection, preventing overheating, and ensuring efficient operation. It helps in selecting appropriate circuit breakers, fuses, and wire sizes.
Tips: Enter the motor's rated power in watts, operating voltage in volts, and the duration of operation in hours. All values must be positive numbers.
Q1: How does FLC differ from starting current?
A: Starting current (inrush current) is typically 5-7 times higher than FLC but lasts only briefly during motor startup.
Q2: Why is time included if it's not in the FLC equation?
A: Time is included to calculate energy consumption (watt-hours), which helps estimate operating costs and thermal effects over time.
Q3: What's a typical FLC for common motors?
A: For a 1 HP motor at 120V, FLC is about 16 amps. At 240V, it's about 8 amps. Actual values depend on motor efficiency and power factor.
Q4: How does power factor affect FLC?
A: This calculator assumes unity power factor. For motors, actual current may be higher due to power factor less than 1.
Q5: Should I size protection devices at FLC?
A: No, protection devices should be sized higher than FLC (typically 125-250% of FLC) to allow for normal operation and startup.