32 | 180R9288_AQ109686503100en-001301 © Danfoss | 2023.12
Operation guide Installation, Operation and Maintenance Manual for PAHT 20-90 pumps
6. Motor
requirements
The required motor power can be calculated by
using the following equation:
n x V x p
P =
600.000 x η
From the ow curves in item 5, you can deter-
mine the rpm of the pump at the desired ow.
The required torque is calculated as follows:
V x p
M =
62.8 x η
To determine the correct motor size, both the
power and torque requirement must be veried.
The mechanical eciency of the pump, at max
pressure, is as follows:
PAHT 2, 3.2, 4, 6.3 0.8
PAHT 10, 12.5 0.9
PAHT 20, 25, 32, 50, 63, 70, 80, 90 0.95
PAHT 256, 308 0.95
P: Power (kW)
M: Torque (Nm)
η: Mechanical eciency
p: Pressure (barg)
n: Motor speed (rpm)
V: Displacement (cm
3
/rev.)