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Full Load Current Formula (3-Phase):
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Full Load Current is the maximum current an electrical device or system draws when operating at its rated capacity. For three-phase systems, it's calculated using power, voltage, power factor, and the √3 constant for three-phase systems.
The calculator uses the 3-phase full load current formula:
Where:
Explanation: This formula calculates the current required by a three-phase electrical system operating at full capacity, accounting for the phase relationship in three-phase power systems.
Details: Accurate full load current calculation is essential for proper circuit breaker sizing, wire gauge selection, transformer sizing, and ensuring electrical system safety and efficiency.
Tips: Enter power in watts, voltage in volts, and power factor (0-1). All values must be valid (power > 0, voltage > 0, 0 < PF ≤ 1).
Q1: What is power factor and why is it important?
A: Power factor represents the ratio of real power to apparent power. It's important because lower power factors require higher currents to deliver the same amount of real power.
Q2: How does this differ from single-phase current calculation?
A: Single-phase systems don't use the √3 factor. The formula for single-phase is: I = P / (V × PF).
Q3: What are typical power factor values?
A: Power factor typically ranges from 0.7 to 1.0. Resistive loads have PF=1, while inductive loads (motors, transformers) have lower power factors.
Q4: When should I use this calculation?
A: Use this for sizing electrical components, circuit protection, and verifying that electrical systems can handle the expected load without overheating.
Q5: Can this calculator be used for DC systems?
A: No, this is specifically for 3-phase AC systems. For DC systems, use I = P / V (no power factor or √3 needed).