Fault Finding The Product; The Pump Does Not Run; The Pump Runs Butdelivers No Flow; The Pump Runs At Reduced Performance - Grundfos SQF Installation And Operating Instructions Manual

9. Fault finding the product

DANGER
Electric shock
Death or serious personal injury
‐
Switch off the power supply before you
start any work on the product.
‐
Make sure that the power supply can-
not be switched on accidentally.
Fault finding and fault correction must be carried out
by qualified persons.
Related information
4. Starting up the product

9.1 The pump does not run

Cause
The fuses in the electric
installation are blown.
No power supply.
The motor protection
has stopped the mo-
tor due to overload.
The pump or the submer-
sible drop cable is defec-
tive.
Overvoltage or undervolt-
age has occurred.
Remedy
Replace the blown fuses.
If the new ones blow too,
check that the electric in-
stallation was made cor-
rectly and that the sub-
mersible drop cable is
OK. If fuses keep blow-
ing, contact a local elec-
trician.
Check the power source.
Remove any blockage of
the pump or the motor
causing the over-
load. Ensure sufficient
power from the power
source.
Check that the electric in-
stallation was made cor-
rectly and that the sub-
mersible drop cable is
OK. Contact the lo-
cal service center to re-
pair or replace the pump
or the submersible drop
cable.
Restore correct power
supply. Check the speci-
fied voltage output from
the power source.
9.2 The pump runs but delivers no flow
Cause
Low power supply.
The outlet valve is
closed.
The non-return valve is
stuck in closed position.
The inlet strainer is clog-
ged.
The pump is defective.

9.3 The pump runs at reduced performance

Cause
The drawdown is larger
than anticipated.
The outlet valve is partly
closed or blocked.
The outlet pipe is partly
clogged by impurities
(ochre).
The non-return valve is
partly blocked.
The pump and the riser
pipe are partly clogged
by impurities (ochre).
The pump is defective.
Leakage in the pipes.
Leakage in the riser pipe.
Low power has occurred.
Remedy
Ensure sufficient power
from the power source.
Open the outlet valve.
Remove the pump from
the borehole and clean
or replace the non-return
valve.
Remove the pump from
the borehole and clean
the inlet strainer.
The pump needs repair.
Remedy
Lower the pump deeper
into the borehole, throttle
the pump or replace it
with a smaller model to
obtain a lower perform-
ance.
Clean the outlet valve or
replace it, if necessary.
Clean the outlet pipe or
replace it, if necessary.
Remove the pump from
the borehole and clean
or replace the non-return
valve.
Remove the pump from
the borehole. Clean or
replace the riser pipe or
the pump, if necessary.
Have the pump re-
paired or replaced.
Repair or replace
the pipes, if necessary.
Repair or replace the ris-
er pipe.
Ensure sufficient power
from the power source.
Check the specified volt-
age output from the pow-
er source.
17