Fault Finding Chart - Grundfos S1 Instrucciones De Instalación Y Funcionamiento

11. Fault finding chart

Warning
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 power supply cannot be accidentally switched on. All rotating parts must
have stopped moving.
The safety instructions in section 4. 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 protective circuit
breaker or protection
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.
22
Cause
a) No power supply.
a) Missing phase.
b) Pump momentarily overloaded.
c) Impeller clogged by impurities.
d) Motor protective circuit breaker 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
activated.
a) Clogged pump causes motor-protective circuit
breaker 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
Reestablish power supply. Start the pump
manually and check contactor operation.
Reestablish all phases.
If the fault does not disappear automatically, find
the cause and remedy the fault.
Clean impeller as required.
Set the motor protective circuit breaker as
required according to rated current.
Reestablish motor cooling.
Contact an authorized service workshop.
Contact an authorized service workshop.
Reestablish correct voltage supply.
Permissible deviation is - 10 %/+ 10 %.
Interchange two phases to the motor.
Tighten or replace the impeller.
Clean as required.
Measure the differential pressure and compare the
value with the pump curve. Remove the blockage
in the discharge pipe.
Clean or replace valves as required.
Vent the pump and suction pipe. Increase the stop
level in the pit.
Dilute the liquid.
Pump down the liquid level in pit. Lift out the pump
and relocate the pump on the auto coupling.
Repair the pipework.
Check function and repair as required.
Clean the pump.
Allow pump to cool. Clean the pump.
Clean or set level switch or replace as required.
Clean the pump.
Interchange two phases to the motor.
Reestablish proper operating conditions.
Repair the pump or contact an authorized
workshop, if necessary.
Pump down the liquid level in pit. Lift out the pump
and relocate the pump on the auto coupling.
Clean the suction pipe.
Install the components correctly.
Contact an authorized service workshop.
Contact an authorized service workshop.