1. What is the Pump Motor Power Formula?

The pump motor power formula calculates the required power for a pump to move fluid at a specified flow rate against a given head, accounting for fluid density and pump efficiency.

2. How Does the Calculator Work?

The calculator uses the pump power equation:

Where:

• \( P \) — Power (kW)
• \( Q \) — Flow rate (m³/h)
• \( H \) — Head (meters)
• \( \rho \) — Density (kg/m³)
• \( g \) — Gravity (9.81 m/s²)
• \( \eta \) — Pump efficiency (0-1)

Explanation: The equation calculates the theoretical power required to move the fluid, then divides by pump efficiency to get actual motor power requirement.

3. Importance of Power Calculation

Details: Proper power calculation ensures correct pump selection, prevents motor overload, and optimizes energy consumption in pumping systems.

4. Using the Calculator

Tips: Enter flow rate in m³/h, head in meters, density in kg/m³ (1000 for water), and pump efficiency as decimal (0.7-0.9 typical). All values must be positive.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical pump efficiency value?
A: Centrifugal pumps typically range 0.7-0.9 (70-90%), but check manufacturer specifications for exact values.

Q2: How does density affect power requirements?
A: Power is directly proportional to density. More dense fluids require more power for the same flow and head.

Q3: Why is gravity in the equation?
A: Gravity accounts for the weight of the fluid being pumped, which determines the work needed to lift it.

Q4: Should I add a safety factor?
A: Yes, it's common practice to add 10-20% safety margin to the calculated power for operational variations.

Q5: What if my flow is in L/s instead of m³/h?
A: Convert L/s to m³/h by multiplying by 3.6 (1 L/s = 3.6 m³/h).