Danfoss PAH 2, Installation, Operation And Maintenance Manual

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Guideline Trouble shooting guide for PAH, PAHT, PAHT C , PAHT G pumps
64 180R9379 | AQ188686503004en-000801 | PAH 2-12.5 } 07.2022
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