Fault Finding; Disposal 13 0.37 - Grundfos CR Series Installation And Operating Instructions Manual

12. Fault finding

Warning
Before removing the terminal box cover and before removing/dismantling the pump, make sure that the power
supply has been switched off and that it cannot be accidentally switched on.
Fault Cause
1. Motor does not run a) Supply failure.
when started.
b) Fuses are blown.
c) Motor-protective circuit breaker has tripped.
d) Thermal protection has tripped.
e) Main contacts in motor-protective circuit breaker
f)
g) Motor is defective.
2. Motor-protective circuit a) One fuse/automatic circuit breaker is blown.
breaker trips
b) Contacts in motor-protective circuit breaker are
immediately when
power supply is
c) Cable connection is loose or faulty.
switched on.
d) Motor winding is defective.
e) Pump mechanically blocked.
f)
3. Motor-protective circuit a) Motor-protective circuit breaker setting is too
breaker trips
occasionally.
b) Low voltage at peak times.
4. Motor-protective circuit a) Check 1 a), b), d), e) and f).
breaker has not tripped
but the pump does not
run.
5. Pump performance not a) Pump inlet pressure is too low (cavitation).
constant.
b) Suction pipe/pump partly blocked by impurities.
c) Pump draws in air.
6. Pump runs but gives no a) Suction pipe/pump blocked by impurities.
water.
b) Foot or non-return valve blocked in closed
c) Leakage in suction pipe.
d) Air in suction pipe or pump.
e) Motor runs in the wrong direction of rotation.
7. Pump runs backwards a) Leakage in suction pipe.
when switched off.
b) Foot or non-return valve defective.
8. Leakage in shaft seal. a) Shaft seal is defective.
9. Noise. a) Cavitation.
b) Pump does not rotate freely (frictional
c) Frequency converter operation.
13. Disposal
This product or parts of it must be disposed of in an
environmentally sound way:
1. Use the public or private waste collection service.
2. If this is not possible, contact the nearest Grundfos company
or service workshop.
are not making contact or the coil is faulty.
Control circuit is defective.
faulty.
Motor-protective circuit breaker setting is too
low.
low.
position.
resistance) because of incorrect pump shaft
position.
Subject to alterations.
Remedy
Connect the power supply.
Replace fuses.
Reactivate the motor-protective circuit breaker.
Reactivate the thermal protection.
Replace contacts or magnetic coil.
Repair the control circuit.
Replace the motor.
Replace the fuse/cut in the circuit breaker.
Replace motor-protective circuit breaker contacts.
Fasten or replace the cable connection.
Replace the motor.
Remove the mechanical blocking of the pump.
Set the motor-protective circuit breaker correctly.
Set the motor-protective circuit breaker correctly.
Check the power supply.
Check the suction conditions.
Clean the suction pipe/pump.
Check the suction conditions.
Clean the suction pipe/pump.
Repair the foot or non-return valve.
Repair the suction pipe.
Check the suction conditions.
Change the direction of rotation of the motor.
Repair the suction pipe.
Repair the foot or non-return valve.
Replace the shaft seal.
Check the suction conditions.
Adjust the pump shaft.
Follow the procedure in fig. F, G or H at the end of
these instructions.
See section
7.5 Frequency converter operation.
13