English (GB)
32
3. The pump runs
but does not
deliver the
rated flow.
a) Wrong direction of rotation.
Interchange two phases in the
power supply to the motor.
b) The impeller is loose or worn.
Tighten or replace the impeller.
c) The pump or the pipes are
blocked by impurities.
Clean the pump or the pipes as
required.
d) The pump head is too high.
Measure the differential pressure
and compare the value with the
pump curve. Remove the blockage
in the outlet pipe.
Second remedy: Contact
Grundfos.
e) The valves are closed or
blocked.
The non-return valve is not
operating.
Open, clean or replace the valves
as required.
f)
There is air in the pump or the
inlet pipe.
Vent the pump or the inlet pipe.
Set a higher stop level in the pit.
g) The pumped liquid is too dense. Dilute the pumped liquid.
h) The pump is not properly
connected to the auto coupling.
Pump down the liquid level in pit.
Lift out the pump and relocate the
pump on the auto coupling.
i)
There is leakage in the pipes.
Repair or replace the pipes.
j)
The pump pit flushing system
has been inadvertently
activated.
Check the function of the flushing
system and repair as required.
4. The pump
starts, but
stops
immediately.
a) A clogged pump causes the
motor-protective circuit breaker
to trip out.
Clean the pump.
b) An overheated motor causes the
thermal switches to trip out.
Allow the pump to cool. Clean the
pump.
c) The level switch is out of
adjustment or defective.
Clean or reset the level switch or
replace as required.
5. The pump is
vibrating or
emitting
excessive
noise.
a) The pump is partly clogged by
impurities.
Clean the pump.
b) Wrong direction of rotation.
Interchange two phases in the
power supply to the motor.
c) The pump is operating outside
the specified operating range.
Re-establish proper operating
conditions.
d) The pump is defective.
Repair the pump or contact an
authorised workshop, if necessary.
e) The pump is not properly
connected to the auto coupling.
Pump down the liquid level in pit.
Lift out the pump and relocate the
pump on the auto coupling.
f)
The pump is cavitating.
Clean the the inlet pipe.
g) The base stand, the auto
coupling, the ring stand or the
guide rails are not installed
correctly.
Install the components correctly.
6. The oil is
watery or
emulsified.
a) The lower mechanical shaft seal
is leaking.
Contact an authorised service
workshop.
7. The oil level is
low.
a) The upper mechanical shaft seal
is leaking.
Contact an authorised service
workshop.
Fault
Cause
Remedy
