1. What is a Pump Motor Power Calculator?

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)
• \( H \) — Total head (feet)
• \( \rho \) — Fluid density (pounds per gallon)
• \( \eta \) — Pump efficiency (decimal)

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

3. Importance of Pump Power Calculation

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

4. Using the Calculator

Tips: Enter flow rate (GPM), total head (ft), 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?
A: Total head is the sum of static head, friction head, and pressure head that the pump must overcome.

Q2: Why 0.746 in the formula?
A: This converts horsepower to kilowatts (1 HP = 0.746 kW).

Q3: What's a typical pump efficiency?
A: Centrifugal pumps typically range from 70-90% efficiency (0.7-0.9).

Q4: How do I find fluid density?
A: Water is 8.34 lb/gal. For other fluids, consult material safety data sheets or density tables.

Q5: Should I add a safety factor?
A: Yes, engineers often add 10-20% to the calculated power for safety margins and future needs.