1. What is 3-Phase Motor HP Calculation?

The 3-phase motor horsepower calculation determines the mechanical power output of an electric motor based on its electrical characteristics. It accounts for voltage, current, power factor, and efficiency to estimate the actual horsepower delivered to the load.

2. How Does the Calculator Work?

The calculator uses the 3-phase HP formula:

Where:

• \( Voltage \) — Line-to-line voltage (V)
• \( Current \) — Phase current (A)
• \( Power\ Factor \) — Ratio of real power to apparent power (0-1)
• \( Efficiency \) — Motor efficiency (0-1)
• 746 — Conversion factor from watts to horsepower

Explanation: The formula calculates the real power (accounting for power factor) and then converts watts to horsepower, while considering motor efficiency.

3. Importance of Motor HP Calculation

Details: Accurate HP calculation helps in motor selection, sizing electrical components, evaluating performance, and energy efficiency assessments.

4. Using the Calculator

Tips: Enter line voltage in volts, current in amps, power factor (typically 0.8-0.95), and efficiency (typically 0.85-0.95 for most motors). All values must be positive.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between input and output HP?
A: Input HP is electrical power, output HP is mechanical power after accounting for efficiency losses in the motor.

Q2: Why use √3 in the formula?
A: √3 accounts for the phase difference in 3-phase power systems when calculating total power from line-to-line measurements.

Q3: What's a typical power factor for motors?
A: Induction motors typically have 0.85-0.9 PF at full load, lower at partial loads. Synchronous motors can achieve 1.0 PF.

Q4: How accurate is this calculation?
A: It provides a good estimate but actual HP may vary due to factors like temperature, voltage variations, and motor condition.

Q5: Can I use this for single-phase motors?
A: No, single-phase motors use a different formula without the √3 factor.