1. What is the 3-Phase kWh Formula?

Definition: This calculator estimates the energy consumption of a 3-phase motor in kilowatt-hours (kWh) based on voltage, current, power factor, and operating time.

Purpose: It helps electrical engineers, technicians, and facility managers calculate energy usage for 3-phase motors and equipment.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( E_{kWh} \) — Energy consumption (kilowatt-hours)
• \( V \) — Voltage (volts)
• \( I \) — Current (amps)
• \( PF \) — Power factor (0 to 1)
• \( t \) — Time (hours)
• \( \sqrt{3} \) — Constant for 3-phase power (≈1.732)

Explanation: The formula calculates real power consumption by accounting for the phase relationship in 3-phase systems.

3. Importance of 3-Phase Energy Calculation

Details: Accurate energy calculation helps in:

• Predicting electricity costs
• Evaluating motor efficiency
• Sizing electrical systems
• Energy conservation planning

4. Using the Calculator

Tips: Enter the voltage (line-to-line), current (per phase), power factor (default 0.85), and operating time in hours. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is power factor and why is it important?
A: Power factor (0-1) represents the phase difference between voltage and current. Lower PF means more apparent power is needed for the same real power.

Q2: How do I find the current (I) value?
A: Measure with a clamp meter or check motor nameplate ratings under full load conditions.

Q3: What's a typical power factor for motors?
A: Induction motors typically have 0.85 PF at full load, but this varies with load and motor design.

Q4: Does this work for single-phase systems?
A: No, for single-phase use \( E_{kWh} = \frac{V \times I \times PF \times t}{1000} \) (without √3).

Q5: How accurate is this calculation?
A: It provides theoretical consumption. Actual usage may vary due to voltage fluctuations, load changes, and motor efficiency.