Fault Finding; Warning; Disposing Of The Product; Frequency Converter - Grundfos CR Serie Instrucciones De Instalación Y Funcionamiento

12. Fault finding

Warning

Before removing the terminal box cover and before
removing or 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) The fuses are blown.
c) The motor-protective circuit breaker has tripped. Reactivate the motor-protective circuit breaker.
d) The thermal protection has tripped.
e) The main contacts in the motor-protective circuit
f)
g) The motor is defective.
2. Motor-protective circuit a) One fuse is blown or the automatic circuit
breaker trips
immediately when
b) The contacts in the motor-protective circuit
power supply is
switched on.
c) The cable connection is loose or faulty.
d) The motor winding is defective.
e) The pump is mechanically blocked.
f)
3. Motor-protective circuit a) The motor-protective circuit breaker setting is
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) The pump inlet pressure is too low (cavitation).
constant.
b) The inlet pipe or pump is partly blocked by
c) The pump draws in air.
6. Pump runs but gives no a) The inlet pipe or pump is blocked by impurities.
water.
b) The foot or non-return valve is blocked in closed
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
7. Pump runs backwards a) There is a leakage in the inlet pipe.
when switched off.
b) The foot or non-return valve is defective.
8. Leakage in shaft seal. a) The shaft seal is defective.
9. Noise. a) Cavitation.
b) The pump does not rotate freely due to frictional
c) Frequency converter operation.

13. Disposing of the product

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.
16
breaker are not making contact or the coil is
faulty.
The control circuit is defective.
breaker is tripped.
breaker are faulty.
The motor-protective circuit breaker setting is
too low.
too low.
impurities.
position.
rotation.
resistance, as a result of incorrect pump shaft
position.
Subject to alterations.
Remedy
Connect the power supply.
Replace fuses.
Reactivate the thermal protection.
Replace contacts or magnetic coil.
Repair the control circuit.
Replace the motor.
Replace the fuse or 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 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. F, G or H at the end of
these instructions.
See section

7.5 Frequency converter

operation.