1. What is Motor Input Power?

Definition: Motor input power is the electrical power consumed by an electric motor, calculated using voltage, current, and power factor.

Purpose: This calculation helps in determining motor efficiency, sizing electrical components, and estimating energy consumption.

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, between 0 and 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 Power Factor

Details: Power factor represents the ratio of real power to apparent power. Motors typically have power factors between 0.7 and 0.9.

4. Using the Calculator

Tips: Enter the voltage in volts, current in amps, and power factor (default 0.8). All values must be > 0, with PF ≤ 1.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical power factor for motors?
A: Induction motors typically have power factors between 0.7-0.9 at full load, lower at partial loads.

Q2: How is this different from output power?
A: Input power is electrical power consumed; output power is mechanical power delivered. The difference represents losses.

Q3: Why measure input power?
A: It helps evaluate motor efficiency, size electrical systems, and calculate operating costs.

Q4: What if I have three-phase power?
A: For three-phase, multiply by √3 (1.732). Use our Three-Phase Power Calculator for this calculation.

Q5: Does this account for motor efficiency?
A: No, this calculates input power only. For output power, multiply by the motor's efficiency factor.