1. What is the Shaft Power to Motor Power Formula?

The shaft power to motor power formula calculates the input power required by a motor to deliver a specified amount of mechanical power at its shaft, accounting for efficiency losses in the system.

2. How Does the Calculator Work?

The calculator uses the motor power formula:

Where:

• \( P_{motor} \) — Motor input power (watts)
• \( P_{shaft} \) — Shaft output power (watts)
• \( \eta \) — System efficiency (decimal between 0 and 1)

Explanation: The formula accounts for energy losses in the motor and drive system, showing that more input power is required than the actual mechanical power delivered at the shaft.

3. Importance of Motor Power Calculation

Details: Accurate motor power calculation is crucial for proper motor selection, energy efficiency assessment, and electrical system design.

4. Using the Calculator

Tips: Enter shaft power in watts and efficiency as a decimal between 0 and 1 (e.g., 0.85 for 85% efficiency). Both values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is typical motor efficiency?
A: Typical AC motor efficiency ranges from 70% for small motors to over 95% for large premium efficiency motors.

Q2: How does this relate to horsepower?
A: 1 HP = 746 watts. You can convert the result to HP by dividing watts by 746.

Q3: Should I include gearbox efficiency?
A: If calculating total system input power, multiply all efficiencies together (motor × gearbox × other components).

Q4: What affects motor efficiency?
A: Efficiency depends on motor size, type, load percentage, quality, and operating conditions.

Q5: How to measure shaft power?
A: Shaft power can be measured using torque sensors or calculated from torque and rotational speed (P = τ × ω).