1. What is Motor Horsepower Calculation from Amps?

Definition: This calculator estimates the horsepower of an electric motor based on its electrical characteristics.

Purpose: It helps engineers and technicians determine motor power output when only electrical measurements are available.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( HP \) — Horsepower output
• \( V \) — Voltage (volts)
• \( I \) — Current (amps)
• \( \eta \) — Motor efficiency (0-1)
• \( PF \) — Power factor (0-1)

Explanation: The formula converts electrical power (considering efficiency and power factor) to mechanical horsepower.

3. Importance of Horsepower Calculation

Details: Accurate horsepower estimation ensures proper motor sizing, energy efficiency, and system compatibility.

4. Using the Calculator

Tips: Enter voltage, current, efficiency (default 0.9), and power factor (default 0.85). Efficiency and power factor must be between 0 and 1.

5. Frequently Asked Questions (FAQ)

Q1: Why divide by 746 in the formula?
A: 1 horsepower equals 746 watts, so we convert watts to HP by dividing.

Q2: What's a typical motor efficiency value?
A: Most electric motors have 85-95% efficiency (0.85-0.95), but check manufacturer specs.

Q3: How do I find the power factor?
A: Use a power meter or check motor specifications (typically 0.8-0.95 for AC motors).

Q4: Does this work for both AC and DC motors?
A: Yes, but for DC motors, set power factor to 1 (no phase difference).

Q5: Can I use this for three-phase motors?
A: For three-phase, multiply voltage by √3 (1.732) first.