Grundfos CR Serie Instrucciones De Instalación Y Funcionamiento página 20

Fault
5. The pump performance
is not constant.
6. The pump runs, but
gives no water.
7. The pump runs
backwards when
switched off.
8. Leakage in shaft seal.
9. Noise.
20
Cause
a) The pump inlet pressure is too
low (cavitation).
b) The inlet pipe or pump is partly
blocked by impurities.
c) The pump draws in air.
a) The inlet pipe or pump is blocked
by impurities.
b) The foot or non-return valve is
blocked in closed position.
c) There is a leakage in the inlet
pipe.
d) There is air in the inlet pipe or
pump.
e) The motor runs in the wrong
direction of rotation.
a) There is a leakage in the inlet
pipe.
b) The foot or non-return valve is
defective.
a) The shaft seal is defective.
a) Cavitation.
b) The pump does not rotate freely
due to frictional resistance as a
result of incorrect pump shaft
position.
c) Frequency converter operation.
Remedy
Check the inlet conditions.
Clean the inlet pipe or pump.
Check the inlet conditions.
Clean the inlet pipe or pump.
Repair the foot or non-return valve.
Repair the inlet pipe.
Check the inlet conditions.
Change the direction of rotation of the
motor.
Repair the inlet pipe.
Repair the foot or non-return valve.
Replace the shaft seal.
Check the inlet conditions.
Adjust the pump shaft.
Follow the procedure in fig. 6, 7,
9 in the appendix.
See section 3.2.4 Frequency
converter operation.
8 or