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Single-Phase Current Formula:
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The single-phase current formula calculates electrical current from power and voltage in single-phase AC or DC systems. This fundamental electrical engineering equation is essential for circuit design, load calculations, and electrical safety assessments.
The calculator uses the single-phase current formula:
Where:
Explanation: This formula represents the direct relationship between power, voltage, and current in electrical systems. For AC systems, this applies when power factor is 1 (resistive loads).
Details: Accurate current calculation is crucial for proper wire sizing, circuit breaker selection, electrical equipment specification, and ensuring electrical system safety and efficiency.
Tips: Enter power in watts and voltage in volts. Both values must be positive numbers. The calculator will compute the current in amperes.
Q1: Does this formula work for both AC and DC systems?
A: Yes, for DC systems and AC systems with unity power factor (resistive loads). For AC with reactive loads, use I = P / (V × PF).
Q2: What is the difference between single-phase and three-phase current calculation?
A: Three-phase systems use different formulas that account for phase relationships and typically include a √3 factor for balanced systems.
Q3: Can I use this for motor current calculations?
A: For motors, additional factors like efficiency and power factor must be considered: I = P / (V × PF × Efficiency).
Q4: What are typical current values in residential applications?
A: Residential circuits typically range from 15A to 50A, with common values being 15A and 20A for general lighting and receptacle circuits.
Q5: How does wire size relate to current calculation?
A: Wire size must be selected based on calculated current to prevent overheating. National Electrical Code (NEC) provides ampacity tables for proper wire sizing.