1. What is the Power Equation?

The power equation (P = V × I × PF) calculates the real power in an AC electrical system. It accounts for voltage (V), current (I), and power factor (PF) which represents the phase difference between voltage and current.

2. How Does the Calculator Work?

The calculator uses the power equation:

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: The calculator can determine any one missing value when the other three are known. It automatically calculates the missing parameter.

3. Importance of Power Factor

Details: Power factor is crucial in AC circuits as it represents the efficiency of power usage. A lower power factor means more current is required to deliver the same amount of real power to the load.

4. Using the Calculator

Tips: Enter any three known values and leave the field you want to calculate empty. The power factor defaults to 0.8 (typical for many industrial loads) but can be adjusted.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical power factor value?
A: Residential: 0.95-1.0, Industrial: 0.8-0.9, Motors at full load: ~0.85. Power factor varies with load type and conditions.

Q2: Why is power factor important for generators?
A: Generators must supply both real power (watts) and reactive power (VARs). Low power factor reduces a generator's effective capacity.

Q3: How can I improve power factor?
A: Power factor correction capacitors can be added to offset inductive loads (like motors) that cause lagging power factor.

Q4: What's the difference between real, apparent, and reactive power?
A: Real power (W) does work, apparent power (VA) is V×I, reactive power (VAR) sustains electromagnetic fields. Power factor = Real/Apparent power.

Q5: Can this calculator be used for DC circuits?
A: Yes, for DC set PF=1 (DC has no phase difference between V and I). The equation simplifies to P = V × I.