Variable Speed / VFD

Scale the pump curve by speed or frequency, find the new operating point, power and energy savings.

Input Parameters

Speed scale by

Rated speed / frequency

Set speed / frequency

Rated flow Q1

m³/h

Rated head H1

Drive power at rated speed

System static head (geometric + back pressure)

System friction coefficient k

m·h²/m⁶

Running hours per year

h/yr

Electricity price

Currency per kWh

Use the affinity laws for speed change. Discharge varies linearly, head as the square and power as the cube of the speed ratio.