Grundfos SL1 Serie Instrucciones De Instalación Y Funcionamiento página 22

11. Fault finding
Warning
Before attempting to diagnose any fault, make sure
that the fuses have been removed or the mains
switch has been switched off. Make sure that the
power supply cannot be accidentally switched on.
All rotating parts must have stopped moving.
Fault
1. Motor does not start.
Fuses blow or motor-
protective circuit breaker trips
immediately.
Caution: Do not start again!
2. Pump operates, but motor-
protective circuit breaker trips
after a short while.
3. The thermal switch of the
pump trips after a short while.
4. Pump operates at below-
standard performance and
power consumption.
5. Pump operates, but gives no
liquid.
6. High power consumption
(SLV).
7. Noisy operation and excessive
vibrations (SL1).
8. Pump clogged.
* Applies only to pumps with sensor and with IO 113.
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Cause
a) Supply failure; short circuit; earth-leakage
fault in cable or motor winding.
b) Fuses blow due to use of wrong type of
fuse.
c) Impeller blocked by impurities.
d) Air bells, float switches or electrodes out of
adjustment or defective.
e) Moisture in the stator housing (alarm).
The IO 113 interrupts the supply voltage.*
f) The WIO sensor is not covered by oil
(alarm). The IO 113 interrupts the supply
voltage.*
g) Stator insulation resistance too low.*
a) Low setting of thermal relay in motor-
protective circuit breaker.
b) Increased current consumption due to
large voltage drop.
c) Impeller blocked by impurities.
Increased current consumption in all three
phases.
d) Wrong direction of rotation.
a) Too high liquid temperature.
b) Too high viscosity of the pumped liquid.
c) Wrong electrical connection. (If the pump
is star-connected to a delta connection,
the result will be very low undervoltage).
a) Impeller blocked by impurities.
b) Wrong direction of rotation.
a) Discharge valve closed or blocked.
b) Non-return valve blocked.
c) Air in pump.
a) Wrong direction of rotation.
b) Impeller blocked by impurities.
a) Wrong direction of rotation.
b) Impeller blocked by impurities.
a) The liquid contains large particles.
b) A float layer has formed on the surface of
the liquid.
Warning
All regulations applying to pumps installed in
potentially explosive environments must be
observed.
Make sure that no work is carried out in potentially
explosive atmosphere.
For pumps with sensor, start fault finding by checking
the status on the IO 113 front panel.
Note
See installation and operating instructions for IO 113.
Remedy
Have the cable and motor checked and repaired by
a qualified electrician.
Fit fuses of the correct type.
Clean the impeller.
Readjust or replace the air bells, float switches or
electrodes.
Replace the O-rings, the shaft seal and moisture
switch.
Check, and possibly replace, the shaft seal, fill up
with oil and reset the IO 113.
Reset alarm on IO 113, see installation and
operating instructions for IO 113.
Set the relay in accordance with the specifications
on the nameplate.
Measure the voltage between two motor phases.
Tolerance: - 10 %/+ 6 %. Reestablish correct
voltage supply.
Clean the impeller.
Check the direction of rotation and possibly
interchange any two of the phases in the incoming
supply cable. See section
Reduce the liquid temperature.
Dilute the pumped liquid.
Check and correct the electrical installation.
Clean the impeller.
Check the direction of rotation and possibly
interchange any two of the phases in the incoming
supply cable. See section
Check the discharge valve and possibly open and/
or clean it.
Clean the non-return valve.
Vent the pump.
Check the direction of rotation and possibly
interchange any two of the phases in the incoming
supply cable. See section
Clean the impeller.
Check the direction of rotation and possibly
interchange any two of the phases in the incoming
supply cable. See section
Clean the impeller.
Select a pump with a larger size of passage.
Install a mixer in the tank.
9.3 Direction of rotation.
9.3 Direction of rotation.
9.3 Direction of rotation.
9.3 Direction of rotation.