1. What is a HP to kW Calculator (3-Phase)?

Definition: This calculator converts horsepower (HP) to kilowatts (kW) for 3-phase electric motors, accounting for motor efficiency and power factor.

Purpose: It helps electrical engineers, technicians, and maintenance professionals accurately size electrical systems and understand power requirements.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( kW \) — Power in kilowatts
• \( HP \) — Horsepower rating
• \( Efficiency \) — Motor efficiency percentage
• \( Power\ Factor \) — Ratio of real power to apparent power (0-1)

Explanation: The formula converts mechanical horsepower to electrical power, adjusting for energy losses (efficiency) and phase characteristics (power factor).

3. Importance of Accurate Conversion

Details: Proper conversion ensures correct electrical system sizing, prevents overloads, and helps with energy efficiency calculations.

4. Using the Calculator

Tips: Enter the motor's horsepower rating, efficiency (default 90%), and power factor (default 0.85). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: Why is 0.746 used in the formula?
A: 1 HP equals 746 watts (0.746 kW), which is the conversion factor between mechanical and electrical power.

Q2: What's a typical motor efficiency?
A: Standard motors range from 85-95% efficiency, with premium motors reaching up to 97%.

Q3: What power factor should I use?
A: Most industrial motors operate at 0.8-0.9 power factor. Check motor nameplate for exact value.

Q4: Does this work for single-phase motors?
A: The formula is similar, but 3-phase motors typically have better power factors and efficiency.

Q5: How do I find my motor's efficiency?
A: Check the motor nameplate or manufacturer specifications. Older motors may need testing.