Pentair PVM 1 Instructions page 16

EN
ORIGINAL INSTRUCTION
THE PUMP ROTATES IN THE WRONG DIRECTION WHEN SWITCHED OFF.
• The foot or the check valve has failed =
Check and replace check valve.
THE FREQUENCY OF PUMP START-UP IS TOO HIGH.
• Leakage in the foot valve, check valve
or system =
Repair or replace the components.
VIBRATION AND NOISE.
• Cavitation = Reduce the required flow
or improve the operating conditions of
the pump (suction conditions, head,
flow resistance, liquid temperature,
viscosity, etc.).
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• Leakage in the suction pipe =
Repair or replace the suction pipe.
• Ruptured membrane or no air pre-
charge in surge tank =
See relevant instructions in surge
tank' s manual.
• Make sure that pump and motor shafts
are properly aligned = Adjust the pump
and/or motor shafts.
• Worn motor bearings = Replace the
bearings or the motor.
• Operation with frequency converter =
Consult a qualified engineer from the
supplier of the frequency converter.
• Check vibration and noise damping
devices = Replace vibration & noise
dampers, if worn.