74 | 180R9288_AQ109686503100en-001301
© Danfoss | 2023.12
Operation guide
Installation, Operation and Maintenance Manual for PAHT 20-90 pumps
Cause
Remedy
Comments
3.1 Too high outlet pressure from pump
3.1.1 Check for blocked nozzles or a faulty
adjusted relief valve.
Pressure changes due to flow restrictions. This
will also cause high motor torque.
3.2 Pump starts against pressure
3.2.1 Check that electric motor is correctly sized.
3.2.2 Check internal parts (see item 2.1).
3.2.3 Systems with more than one electric motor
installed:
Start motors simultaneously.
Pumps run in parallel with cascade start, may
switch off the motor relay due to too high
torque caused by high outlet pressure.
3.3 Constant torque
3.3.1 Please contact Danfoss High Pressure
Pumps sales office.
If the electric motor is too small for the pump, it
cannot provide sufficient torque.
3.4 Water pump damage
3.4.1 Dismantle pump and check for wear.
Too heavy damage in the pump will increase
friction causing a high torque (see item 6,
Typical signs of wear).
3.
High torque on electric motor
