1. What is the Motor Power Formula?

The motor power formula calculates horsepower (HP) from torque and rotational speed. This fundamental equation is essential for proper electric motor selection and sizing in mechanical applications.

2. How Does the Calculator Work?

The calculator uses the motor power formula:

Where:

• \( P \) — Motor power in horsepower (HP)
• \( Torque \) — Rotational force in pound-feet (lb-ft)
• \( Speed \) — Rotational speed in revolutions per minute (RPM)
• \( 5252 \) — Conversion constant (derived from unit conversions)

Explanation: The constant 5252 comes from the conversion between different units of power and rotational speed, making this formula specific to the HP, lb-ft, and RPM units.

3. Importance of Motor Sizing

Details: Proper motor sizing is crucial for efficient operation, preventing motor burnout, ensuring adequate torque for startup and operation, and optimizing energy consumption in industrial and mechanical applications.

4. Using the Calculator

Tips: Enter torque in lb-ft and speed in RPM. Both values must be positive numbers. The calculator will compute the required motor power in horsepower.

5. Frequently Asked Questions (FAQ)

Q1: Why is the constant 5252 used in this formula?
A: The constant 5252 comes from unit conversions: 1 horsepower = 550 foot-pounds per second, and there are 60 seconds in a minute (550 × 60 ÷ 2π ≈ 5252).

Q2: What is a typical torque range for electric motors?
A: Torque ranges vary widely by motor size and type, from less than 1 lb-ft for small motors to over 1000 lb-ft for large industrial motors.

Q3: How does motor speed affect power requirements?
A: Higher speeds generally require more power for the same torque, as power is directly proportional to both torque and speed in this relationship.

Q4: What safety factor should I use when selecting a motor?
A: Typically, a 15-25% safety margin is recommended to account for startup torque, load variations, and potential overload conditions.

Q5: Can this formula be used for all types of motors?
A: This formula applies to rotational mechanical power calculations and can be used for various motor types including AC, DC, and induction motors when calculating mechanical output power.