1. What is a Motor Input Power Calculator?

Definition: This calculator determines the electrical input power required by a motor based on voltage, current, and power factor.

Purpose: It helps electrical engineers, technicians, and DIYers properly size electrical systems and understand motor power requirements.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( P_w \) — Input power (watts)
• \( V \) — Voltage (volts)
• \( I \) — Current (amps)
• \( PF \) — Power factor (unitless, 0-1)

Explanation: The product of voltage and current gives apparent power, which is then multiplied by the power factor to get real power.

3. Importance of Motor Power Calculation

Details: Accurate power calculations ensure proper circuit sizing, prevent overloads, and help estimate energy consumption.

4. Using the Calculator

Tips: Enter the voltage in volts, current in amps, and power factor (default 0.8). Power factor must be between 0 and 1.

5. Frequently Asked Questions (FAQ)

Q1: What is power factor?
A: Power factor is the ratio of real power to apparent power, representing how effectively current is converted to useful work.

Q2: What's a typical power factor value?
A: Induction motors typically have 0.8-0.9 PF at full load, but this varies with motor type and load conditions.

Q3: How do I measure voltage and current?
A: Use a multimeter - measure voltage across motor terminals and current through one power lead.

Q4: Does this calculate input or output power?
A: This calculates electrical input power. Output mechanical power would be less due to efficiency losses.

Q5: What about three-phase motors?
A: For three-phase, multiply by √3 (1.732) and use line-to-line voltage.