1. What is Electrical Power?

Electrical power is the rate at which electrical energy is transferred by an electric circuit. In AC circuits, the actual power consumed depends on the power factor, which represents the phase difference between voltage and current.

2. How Does the Calculator Work?

The calculator uses the electrical power formula:

For three-phase systems, the formula becomes:

Where:

• \( P \) — Power in watts (W)
• \( V \) — Voltage in volts (V)
• \( I \) — Current in amperes (A)
• \( PF \) — Power factor (unitless, between 0 and 1)
• \( \sqrt{3} \) — Approximately 1.732 (three-phase multiplier)

Explanation: The power factor accounts for the phase difference between voltage and current in AC circuits. For purely resistive loads, PF = 1.

3. Importance of Power Calculation

Details: Accurate power calculation is essential for circuit design, energy consumption estimation, electrical system sizing, and determining operating costs.

4. Using the Calculator

Tips: Enter voltage in volts, current in amperes, and power factor (0 to 1). Select single-phase or three-phase system. All values must be valid (voltage > 0, current > 0, 0 ≤ PF ≤ 1).

5. Frequently Asked Questions (FAQ)

Q1: What is power factor?
A: Power factor is the ratio of real power (watts) to apparent power (volt-amperes). It ranges from 0 to 1, with 1 being most efficient.

Q2: When should I use the three-phase calculation?
A: Use three-phase for commercial/industrial power systems, large motors, and any equipment specifically designed for three-phase power.

Q3: What's a typical power factor value?
A: Resistive loads (heaters, incandescent lights) have PF=1. Motors typically 0.8-0.9. Electronic devices often 0.6-0.7.

Q4: How does power factor affect energy consumption?
A: Lower power factor means more current is needed for the same real power, increasing line losses and possibly utility charges.

Q5: Can I use this for DC circuits?
A: Yes, for DC set PF=1 (no phase difference in DC). The three-phase option doesn't apply to DC.