Fault Finding Chart - Grundfos S1 Bedienungsanleitung

8. Fault finding chart

Before attempting to diagnose any fault, make sure that the fuses have been removed or the mains switch has been switched
off. It must be ensured that the electricity supply cannot be accidentally switched on. All rotating parts must have stopped
moving.
The safety instructions in section 2. Safety must be read and observed.
Fault
1. Pump does not start or
stops without visible cause.
2. Pump does not start or
stops. The control panel of
the controller indicates that
the motor starter or protec-
tion equipment has tripped
out.
3. Pump runs but does not
deliver the rated flow.
4. Pump starts, but stops
immediately.
5. Pump vibrating or emitting
excessive noise.
6. Oil watery or emulsified.
7. Low oil level.
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Cause
a) No electricity supply.
a) Missing phase.
b) Pump momentarily overloaded.
c) Impeller blocked by impurities.
d) Motor starter not set correctly.
e) Thermal switches tripped out. Insufficient
motor cooling.
f) Moisture switch in motor tripped out.
g) Motor cable defective.
h) Fluctuating voltage.
a) Wrong direction of rotation.
b) Impeller loose or worn.
c) Pump or pipework blocked by impurities.
d) Pump head too high.
e) Valves closed or blocked.
Non-return valve not operating.
f) Air in pump or suction pipe.
g) Pumped liquid too dense.
h) Pump not properly connected to auto-
coupling.
i) Leakage in pipework.
j) Pump pit flushing system inadvertently acti-
vated.
a) Clogged pump causes motor starter to trip
out.
b) Overheated motor causes thermal switches
to trip out.
c) Level switch out of adjustment or defective.
a) Pump partly choked by impurities.
b) Wrong direction of rotation.
c) Pump operates outside specified operating
range.
d) Pump defective.
e) Pump not properly connected to auto-
coupling.
f) Pump cavitates.
g) Base stand, auto-coupling, ring stand or
guide rails not installed correctly.
a) Lower mechanical seal leaking.
a) Upper mechanical seal leaking.
Remedy
Check electricity supply and fuses. Start the pump
manually and check contactor operation.
Check electricity supply and fuses.
If the fault does not disappear automatically, find the
cause.
Check impeller and clean as required.
Check and set as required according to rated
current.
Allow the motor to cool. Ensure adequate cooling by
lowering the pump into the liquid, versions 1 and 4.
Contact authorized service workshop.
Check for visual damages. Contact authorized
service workshop.
Check voltage. Permissible deviation is ±5%.
Check the direction of rotation and possibly inter-
change two phases to the motor.
Check impeller and adjust as required.
Check pump and pipework and clean as required.
Check by measuring the pressure and reinstall
discharge pipe or install new pump.
Check valve position and clean as required.
Vent the pump and suction pipe. Increase the stop
level in the pit or reinstall suction pipe.
Dilute the liquid or change the process.
Pump down the liquid level in pit. Lift out the pump
and relocate the pump on the auto-coupling.
Check pipework for leaks and make tight as
required.
Check function and repair as required.
Check pump and clean as required.
Allow pump to cool. Check for cause as above.
Clean or set level switch or replace as required.
Check pump and clean as required.
Check the direction of rotation and possibly inter-
change two phases to the motor.
Check operating conditions.
Check pump for damages. Repair the pump or con-
tact an authorized workshop, if necessary.
Pump down the liquid level in pit. Lift out the pump
and relocate the pump on the auto-coupling.
Check pump for partial suction blockage and clean
as required. Check duty point and adjust as
required.
Check installation and tighten bolts where
necessary.
Contact authorized service workshop.
Contact authorized service workshop.