1. What is Pump Motor Power Calculation?

The motor power calculation determines the required power for a pump to move a fluid at a specified flow rate against a given head, considering fluid properties and system efficiency. It's essential for proper pump selection and energy-efficient operation.

2. How Does the Calculator Work?

The calculator uses the motor power formula:

Where:

• \( P \) — Motor power (kW)
• \( Q \) — Flow rate (m³/h)
• \( H \) — Head (m)
• \( \rho \) — Fluid density (kg/m³)
• \( g \) — Gravitational acceleration (9.81 m/s²)
• \( \eta \) — Pump efficiency (0-1)

Explanation: The formula calculates the hydraulic power needed to move the fluid and divides it by the pump efficiency to determine the required motor power.

3. Importance of Proper Pump Sizing

Details: Correct motor sizing ensures energy efficiency, prevents motor overload, extends equipment life, and reduces operating costs. Oversized motors waste energy while undersized motors may fail prematurely.

4. Using the Calculator

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

5. Frequently Asked Questions (FAQ)

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

Q2: How do I account for system losses?
A: Include safety factors (10-20%) or calculate total dynamic head that includes pipe friction losses.

Q3: What density should I use for other fluids?
A: For fluids other than water, use their specific density (e.g., oil ~800-900 kg/m³, seawater ~1025 kg/m³).

Q4: Should I consider motor efficiency too?
A: This calculation gives hydraulic power. For electrical input power, divide by motor efficiency (typically 0.85-0.95).

Q5: How does viscosity affect the calculation?
A: High viscosity fluids require more power and reduce pump efficiency. Special corrections may be needed.