Troubleshooting - Grundfos SE Serie Instrucciones De Instalación Y Operación

11. Troubleshooting

DANGER
Electric shock
Death or serious personal injury
‐
Before starting any work on the product, make sure
that the power supply is switched off and it cannot be
switched on unintentionally.
WARNING
Crushing hazard
Death or serious personal injury
‐
Before diagnosing any fault, make sure that all rotating
parts have stopped moving.
Fault
The pump does not start or stops without visible cause.
The pump does not start or stops. The control panel of
the controller indicates that the motor-protective circuit
breaker or protection equipment is tripped.
The pump runs, but does not deliver the rated flow.
The pump starts, but stops immediately.
The pump is vibrating or emitting excessive noise.
24
DANGER
Electric shock
Death or serious personal injury
‐
Make sure the pump is grounded.
Observe all regulations applying to pumps installed in
potentially explosive environments.
FM
Make sure that no work is carried out in potentially
explosive atmospheres.
Cause
No power supply.
A phase is missing.
The pump is overloaded.
The impeller is clogged by impurities.
The motor-protective circuit breaker is
set incorrectly.
The thermal switches are tripped due
to insufficient motor cooling.
The moisture switch in the motor is
tripped.
The motor cable is defective.
The voltage is fluctuating.
The direction of rotation is wrong.
The impeller is loose or worn.
The pump or pipes are blocked by
impurities.
The pump head is too high.
The valves are closed or blocked. The
check valve is not operating.
There is air in the pump or the inlet
pipe.
The pumped liquid is too dense.
The pump is improperly connected to
the auto coupling.
The pipes are leaking.
The pump pit flushing system is
inadvertently activated.
The pump is clogged which causes
the motor-protective circuit breaker to
trip.
The motor is overheated which causes
thermal switches to trip.
The level switches are out of
adjustment or defective.
The pump is partly clogged by
impurities.
The direction of rotation is wrong.
Remedy
Re-establish the power supply. Start the
pump manually.
Re-establish all phases.
If the fault does not disappear
automatically, find the cause and remedy
the fault.
Clean the impeller.
Set the motor-protective circuit breaker
according to the rated current.
Re-establish the motor cooling.
Contact an authorized service workshop.
Contact an authorized service workshop.
Re-establish the correct voltage supply.
Permissible deviation is ± 10 %.
Interchange two phases to the motor.
Tighten or replace the impeller.
Clean the pump or the pipes.
Measure the differential pressure and
compare the value with the pump curve.
Remove any blockage in the outlet pipe.
Clean or replace the valves.
Vent the pump and the inlet pipe.
Increase the stop level in the pit.
Dilute the pumped liquid.
Pump down the liquid level in the pit. Lift
out the pump and place it on the auto
coupling again.
Repair the pipes.
Check the function of the pit flushing
system and repair it, if required.
Clean the pump.
Allow the pump to cool. Clean the pump.
Clean or set the level switches or replace
them, if required.
Clean the pump.
Interchange two phases to the motor.