Grundfos SE Installation And Operating Instructions Manual page 30

Fault
The pump starts, but stops immediately.
The pump is vibrating or emitting
excessive noise.
Low motor liquid level.
30
Cause
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.
There is leakage in the pipes.
The 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 the thermal
switches to trip.
The level switch is out of
adjustment or defective.
The pump is partly clogged by
impurities.
The direction of rotation is
wrong.
The pump is operating outside
the specified operating range.
The pump is defective.
The pump is not properly
connected to the auto
coupling.
The pump is cavitating.
The impeller is not in balance.
The base stand, the auto
coupling, the ring stand or the
guide rails are installed
incorrectly.
The upper mechanical shaft
seal is leaking.
Remedy
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 switch or
replace them, if required.
Clean the pump.
Interchange two phases to the
motor.
Re-establish proper operating
conditions.
Repair the pump or contact an
authorised workshop, if
necessary.
Pump down the liquid level in the
pit. Lift out the pump and place
the pump on the auto coupling.
Clean the inlet pipe.
Contact an authorised service
workshop.
Install the components correctly.
Contact an authorised service
workshop.