1. What is the Motor Power Equation?

The motor power equation (P = V × I) calculates the electrical power consumed by a motor based on voltage and current. It's a fundamental equation in electrical engineering for determining power requirements and efficiency.

2. How Does the Calculator Work?

The calculator uses the basic power equation:

Where:

• \( P \) — Power in watts (W)
• \( V \) — Voltage in volts (V)
• \( I \) — Current in amperes (A)

Explanation: This equation represents the instantaneous electrical power being consumed by the motor. For AC systems, this would be the apparent power.

3. Importance of Power Calculation

Details: Calculating motor power is essential for proper circuit design, selecting appropriate wiring and protection devices, and determining energy consumption and operating costs.

4. Using the Calculator

Tips: Enter voltage in volts and current in amps. Both values must be positive numbers. For three-phase systems, additional calculations would be needed.

5. Frequently Asked Questions (FAQ)

Q1: Is this calculation the same for AC and DC motors?
A: For DC motors, this gives true power. For AC motors, this gives apparent power (VA) - you would need power factor for true power.

Q2: How does efficiency factor into this?
A: The calculated power is electrical input power. Mechanical output power would be less due to efficiency losses.

Q3: What about three-phase motors?
A: Three-phase power calculation requires multiplying by √3 (1.732) and power factor: P = √3 × V × I × PF.

Q4: Can I use this for motor sizing?
A: This gives input power. For motor sizing, you need to consider mechanical load requirements and efficiency.

Q5: What are typical voltage and current ranges for motors?
A: Small motors might use 12-24V, while industrial motors often use 240V, 480V or higher. Current varies with power.