How Many Amps Does a 5HP Submersible Pump Draw, and What Are the Key Factors to Consider?

When it comes to the electrical requirements for a submersible pump, understanding the current draw in amps is crucial for proper electrical system design and safety. This article will guide you through the formula to calculate the amps drawn by a 5HP submersible pump and explore the key factors that influence this value.

Calculating Amps Drawn

To calculate the current in amps drawn by a 5HP submersible pump, we use the following formula:

Amps (Horsepower times; 746) / (Voltage times; Efficiency)

Where:

746 is the number of watts in one horsepower. Voltage is the operating voltage of the pump, commonly 230V or 460V. Efficiency is the efficiency of the pump, typically between 0.7 and 0.9 for submersible pumps.

Example Calculation

Let's assume a 5HP submersible pump with the following specifications:

Voltage: 230V Efficiency: 0.85

First, convert horsepower to watts:

5 HP times; 746 W/HP 3730 W

Then, calculate the current:

Amps 3730 W / (230 V times; 0.85) ≈ 23.6 amps

The Answer Is Dependent on Supply Voltage

The current draw for a 5HP submersible pump is dependent on the supply voltage and can vary. Here's how it breaks down:

Single Phase 230V

Since 1 HP equals 735.5 Watts, for 5 HP, we have:

5 HP times; 735.5 W/HP 3677.5 Watts

This assumes 100% efficiency:

Amps 3677.5 W / 230 V 15.989 Amps

Three Phase 415V

For a three-phase system with a rated voltage of 415V, the current:

Amps 3677.5 W / 415 V 8.861 Amps

Main Factors Determining Current Draw

The main factors that influence the current draw of a 5HP submersible pump are the service voltage and the number of phases (single or three).

Three Phase 230VAC Motor by Franklin

Full Load Amps: 15.9A Max. SF Amps: 17.8A Service Factor SF: 1.15

Similar Pump on Single Phase 230VAC

Full Load: 23 A Maximum SF: 27.5 A

These are running currents; starting currents are usually 2-3x higher for across the line starts but much lower if a soft or reduced voltage starter is used.

Conclusion

For a 5HP submersible pump operating at 230V and 85% efficiency, the current draw would be approximately 23.6 amps. However, the actual current draw may vary based on specific pump ratings and operating conditions.

Properly calculating the current draw is essential for ensuring that your electrical system can safely handle the load. Always refer to the manufacturer's specifications for accurate ratings and consult an electrician if you have any uncertainties.