1. What is Pump Motor Power Calculation?

Definition: This calculator estimates the required motor power for a pump based on flow rate, total head, fluid density, and pump efficiency.

Purpose: It helps engineers and technicians properly size pump motors for various fluid transfer applications.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( P_e \) — Motor power (kW)
• \( Q \) — Flow rate (gallons per minute, GPM)
• \( H \) — Total head (feet, ft)
• \( \rho \) — Fluid density (pounds per gallon, lb/gal)
• \( \eta \) — Pump efficiency (decimal, 0-1)

Explanation: The formula calculates the hydraulic power and converts it to motor power in kilowatts, accounting for pump efficiency.

3. Importance of Pump Power Calculation

Details: Proper pump motor sizing ensures efficient operation, prevents motor overload, and reduces energy costs.

4. Using the Calculator

Tips: Enter the flow rate in GPM, total head in feet, fluid density (default 8.34 lb/gal for water), and pump efficiency (default 0.85). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is total head (H)?
A: Total head is the sum of static head, friction head, and pressure head that the pump must overcome.

Q2: What's a typical pump efficiency value?
A: Centrifugal pumps typically range from 0.7 to 0.9 (70-90%) efficiency depending on size and design.

Q3: Why is density important?
A: Denser fluids require more power to pump at the same flow rate and head.

Q4: How do I convert the result to horsepower?
A: Divide the kW result by 0.746 to get horsepower (HP).

Q5: Should I add a safety factor?
A: Yes, it's common practice to add 10-20% to the calculated power for safety margin.