1. What is Motor Torque?

Torque is the rotational force produced by a motor. In single-phase motors, torque is crucial for determining the motor's ability to perform work and overcome load resistance.

2. How Does the Calculator Work?

The calculator uses the torque formula:

Where:

• \( Power \) — Motor power in kilowatts (kW)
• \( RPM \) — Rotational speed in revolutions per minute
• 9550 — Conversion constant (derived from unit conversions)

Explanation: The formula relates the motor's power output to its rotational speed, showing that torque decreases as speed increases for a given power.

3. Importance of Torque Calculation

Details: Knowing the torque helps in selecting the right motor for an application, ensuring it can handle the starting and running loads without stalling.

4. Using the Calculator

Tips: Enter the motor's rated power in kW and its operating speed in RPM. Both values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: Why is 9550 used in the formula?
A: 9550 comes from unit conversions: (60 sec/min × 1000 W/kW) / (2π rad/rev) ≈ 9549.3, rounded to 9550 for practical calculations.

Q2: What is typical torque for single-phase motors?
A: Torque varies by motor size and design, but common single-phase motors (0.5-2 kW) might produce 3-15 Nm at rated speed.

Q3: Does this work for three-phase motors?
A: Yes, the basic torque formula applies to all AC motors, but three-phase motors typically have better starting torque characteristics.

Q4: How does voltage affect torque?
A: Torque is proportional to the square of the voltage. A 10% voltage drop results in about 19% torque reduction.

Q5: What about starting torque vs running torque?
A: This calculator gives running torque at rated speed. Starting torque (at zero speed) is typically higher but depends on motor design.