High Torque On Electric Motor - Danfoss APP Series Installation, Operation And Maintenance Manual

Operation guide
3.

High torque on electric motor

Cause
3.1 Too high outlet pressure from pump
3.2 Pump starts against pressure
3.3 Constant torque
106 | 180R9346 | AQ240486503020en-001702
Installation, Operation and Maintenance APP 53-92 pumps
Remedy
3.1.1 Check fluid salinity.
3.1.2 Check temperature.
3.1.3 Check pressure drop across RO membrane.
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.
3.3.1 Please contact Danfoss High Pressure
Pumps sales office.
Comments
Pump conditions may change (more salt, lower
water temperature or scaling of RO membrane)
causing higher pressure, resulting in higher
motor torque.
Pumps run in parallel with cascade start, may
switch off the motor relay due to too high
torque caused by high outlet pressure.
If the electric motor is too small for the APP, APP S
or APP S 674 pump, it cannot provide sufficient
torque.
© Danfoss | 2023.03