Motor Power Calculator For Pump

Pump Power Equation:

\[ P = \frac{Q \times \rho \times g \times H}{3600 \times \eta} \]

Flow Rate (Q):

m³/h

Density (ρ):

kg/m³

Head (H):

Efficiency (η):

(0-1)

Motor Power (P):

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1. What is Pump Motor Power Calculation?

The pump motor power calculation determines the required power for a pump motor based on flow rate, fluid density, head, and pump efficiency. This is essential for proper pump selection and energy efficiency optimization.

2. How Does the Calculator Work?

The calculator uses the pump power equation:

\[ P = \frac{Q \times \rho \times g \times H}{3600 \times \eta} \]

Where:

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

Explanation: The equation calculates the hydraulic power required to move fluid against gravity and system resistance, then accounts for pump efficiency to determine actual motor power.

3. Importance of Motor Power Calculation

Details: Accurate motor power calculation ensures proper pump sizing, prevents motor overload, optimizes energy consumption, and extends equipment lifespan. Undersized motors can burn out, while oversized motors waste energy and increase costs.

4. Using the Calculator

Tips: Enter flow rate in m³/h, density in kg/m³ (water ≈ 1000 kg/m³), head in meters, and efficiency as decimal (e.g., 0.85 for 85%). All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is typical pump efficiency?
A: Pump efficiency typically ranges from 60% to 85%, depending on pump type, size, and operating conditions. Centrifugal pumps usually have 70-85% efficiency.

Q2: How do I account for motor efficiency?
A: This calculation gives hydraulic power. For electrical input power, divide the result by motor efficiency (typically 85-95%).

Q3: What density should I use for water?
A: Pure water at 4°C has density of 1000 kg/m³. For other temperatures, use 998 kg/m³ (20°C) or consult density tables.

Q4: Does this include safety factors?
A: No, this is theoretical calculation. Always apply appropriate safety factors (typically 10-20%) for practical applications.

Q5: Can this be used for all pump types?
A: This formula works for centrifugal and positive displacement pumps, but head calculation may vary for different pump types and system configurations.