1. What is the Power Formula?

The power formula (P = V × I × PF) calculates the real power in an AC circuit by multiplying voltage (V), current (I), and power factor (PF). It provides the actual power being consumed in watts.

2. How Does the Calculator Work?

The calculator uses the power formula:

Where:

• \( P \) — Real power in watts (W)
• \( V \) — Voltage in volts (V)
• \( I \) — Current in amperes (A)
• \( PF \) — Power factor (unitless, 0 to 1)

Explanation: For DC circuits or purely resistive AC loads, the power factor is 1. For AC circuits with reactive components, the power factor accounts for phase difference between voltage and current.

3. Importance of Power Calculation

Details: Accurate power calculation is crucial for electrical system design, energy consumption estimation, circuit protection sizing, and efficiency calculations.

4. Using the Calculator

Tips: Enter voltage in volts, current in amps, and power factor (1 for DC or resistive AC circuits). All values must be valid (voltage > 0, current > 0, 0 ≤ PF ≤ 1).

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between real power and apparent power?
A: Real power (watts) is the actual power consumed, while apparent power (VA) is the product of voltage and current without considering power factor.

Q2: When should I use a power factor less than 1?
A: For AC circuits with inductive or capacitive loads (motors, transformers, etc.) where current and voltage are not in phase.

Q3: What is a typical power factor value?
A: Residential: 0.95-1.0, Industrial: 0.8-0.9. Power factors below 0.8 may require correction.

Q4: How does this differ from three-phase power calculation?
A: Three-phase power uses P = √3 × V × I × PF (line-to-line voltage) or P = 3 × V × I × PF (line-to-neutral).

Q5: Why is power factor important?
A: Low power factor means higher current is needed for the same real power, increasing energy losses and infrastructure costs.