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Electrical Power Formula:
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Electrical power (measured in watts) is the rate at which electrical energy is transferred by an electric circuit. The basic formula for calculating power in DC circuits or AC circuits with resistive loads is P = V × I. For AC circuits with reactive components, the power factor must be considered.
The calculator uses the electrical power formula:
Where:
Explanation: This formula calculates real power in an electrical circuit. For DC circuits or purely resistive AC circuits, the power factor is 1. For AC circuits with inductive or capacitive loads, the power factor is less than 1.
Details: Calculating electrical power is essential for designing electrical systems, sizing components, determining energy consumption, and ensuring electrical safety. It helps in selecting appropriate wire sizes, circuit breakers, and power supplies.
Tips: Enter voltage in volts, current in amperes, and power factor (1 for DC or resistive AC circuits). All values must be valid (voltage > 0, current > 0, power factor between 0-1).
Q1: What's the difference between real power and apparent power?
A: Real power (watts) is the actual power consumed by the circuit. Apparent power (VA) is the product of voltage and current. The ratio between them is the power factor.
Q2: When should I use a power factor less than 1?
A: Use PF < 1 for AC circuits with inductive (motors, transformers) or capacitive loads where current and voltage are out of phase.
Q3: What's a typical power factor value?
A: For residential homes, PF is typically 0.95-1. Industrial loads with motors might have PF of 0.7-0.9.
Q4: How does this relate to energy consumption?
A: Energy (kWh) = Power (kW) × Time (hours). This calculator gives you the power component of that equation.
Q5: Can I use this for three-phase power calculations?
A: For balanced three-phase systems, use P = √3 × V × I × PF where V is line-to-line voltage.