What this tool does
Separate useful hydraulic power from pump-shaft and motor input power so efficiency assumptions are visible.
When to use it
Use it after flow and total head are defined and when a pump or scenario efficiency can be read from a manufacturer curve or measured.
Inputs and supported units
Each labelled field explains the quantity it expects. Unit-system changes convert existing numeric entries once and keep calculations on a single SI internal basis. Supported shared units include L/min and GPM, metres and feet, kPa and psi, millimetres and inches, kW and hp, and °C and °F as relevant.
Calculation or decision method
Pshaft = Phydraulic/ηpump
Pelectrical = Pshaft/ηmotor
How to interpret the result
Read the primary result with the supporting breakdown and warning. A plausible number is not evidence that every input, operating case or design constraint has been included.
Worked example
At 120 L/min and 50 m head with 70% pump efficiency and 90% motor efficiency, estimated electrical input is about 1.56 kW.
Assumptions
Steady water flow; entered efficiencies apply at the duty point; direct drive with no additional drive loss.
Limitations
No motor part-load curve, service factor, starting current, drive loss or variable-speed map is included.
Sources
- U.S. Department of Energy — Pumping System Assessment Tool User’s Manual
- U.S. Department of Energy — Pump Systems
- Hydraulic Institute — Pump FAQs