1. What is Power Factor?

Power factor (PF) is the ratio of real power (measured in watts) to apparent power (measured in volt-amperes) in an AC electrical system. For electric motors, it indicates how effectively the motor converts electrical power into mechanical power.

2. How Does the Calculator Work?

The calculator uses the power factor formula:

Where:

• \( PF \) — Power factor (unitless, range 0-1)
• \( P \) — Real power in watts
• \( V \) — Voltage in volts
• \( I \) — Current in amps

Explanation: This formula calculates the power factor for single-phase AC systems. The result is always between 0 (worst) and 1 (ideal).

3. Importance of Power Factor

Details: A high power factor (close to 1) indicates efficient power usage. Low power factor means the motor draws more current to deliver the same power, increasing energy losses and potentially causing voltage drops.

4. Using the Calculator

Tips: Enter the motor's rated power in watts, operating voltage in volts, and current draw in amps. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is a good power factor for electric motors?
A: Most AC induction motors have a power factor between 0.85-0.90 at full load. Power factor decreases at partial loads.

Q2: How can I improve power factor?
A: Power factor correction capacitors can be installed near motors to reduce reactive power demand.

Q3: Does this calculator work for three-phase motors?
A: No, for three-phase systems you need to include the √3 (1.732) factor in the calculation.

Q4: Why does power factor matter for utilities?
A: Utilities often charge penalties for low power factor because it increases transmission losses.

Q5: What causes low power factor?
A: Induction motors running at partial load, transformers with low load, and other inductive loads can cause low power factor.