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 flow curves in item 5, you can deter-
mine the rpm of the pump at the desired flow.
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 verified.
The mechanical efficiency 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 efficiency
p: Pressure (barg)
n: Motor speed (rpm)
V: Displacement (cm
3
/rev.)
