1. What is the Pump Power Equation?

The pump power equation calculates the required horsepower for a submersible well pump based on flow rate, total head, specific gravity of the fluid, and pump efficiency. It's essential for selecting the right pump size for your well system.

2. How Does the Calculator Work?

The calculator uses the pump power formula:

Where:

• \( HP \) — Required horsepower
• \( Q \) — Flow rate in gallons per minute (GPM)
• \( H \) — Total dynamic head in feet
• \( SG \) — Specific gravity of fluid (1.0 for water)
• \( \eta \) — Pump efficiency (typically 0.7-0.9)
• 3960 — Conversion factor

Explanation: The equation calculates the power needed to move a specific volume of fluid against a certain head pressure, accounting for the pump's efficiency.

3. Importance of Proper Pump Sizing

Details: Correct pump sizing ensures efficient operation, prevents premature failure, and matches your water demand. Oversized pumps waste energy while undersized pumps can't meet demand.

4. Using the Calculator

Tips:

• Measure flow rate based on your water usage needs
• Calculate total head as static head plus friction losses
• Use 1.0 for specific gravity unless pumping other fluids
• Typical pump efficiency ranges from 70-90% (0.7-0.9)

5. Frequently Asked Questions (FAQ)

Q1: What is total dynamic head?
A: It's the vertical distance from water level to discharge point plus friction losses in pipes and fittings.

Q2: How do I determine my flow rate needs?
A: Calculate based on peak water demand - typically 5-10 GPM for households, more for irrigation.

Q3: What's a typical pump efficiency?
A: Good submersible pumps have 70-85% efficiency. Check manufacturer specifications.

Q4: Should I round up the calculated HP?
A: Yes, select the next available pump size to ensure adequate capacity.

Q5: Does this account for starting torque?
A: No, for motors with high starting loads, additional capacity may be needed.