12. Fault finding
DANGER
Electric shock
Death or serious personal injury
‐
Before performing any work on a pump or control
panel, switch off the power supply and lock the
general main switch in position OFF to ensure that the
power supply cannot be accidentally switched on.
For failures relating to the diesel engine or pump, refer to the
specific installation and operating instructions delivered with the
pump set.
12.1 The electric pump does not start
Cause
Remedy
There is no mains supply.
•
Connect the power supply.
The general switch is off.
•
Turn on the general switch.
The fuse is defective.
•
Replace the fuse.
The electrical circuit is
interrupted or defective.
•
Check and repair the
electrical circuit.
The pump is blocked.
•
The hydraulics
are blocked. Dismantle and
clean the pump. See the
installation and operating
instructions of the pump.
There is an electric motor
failure.
•
Repair or replace the electric
motor. See the installation and
operating instructions of the
electric motor.
12.2 The diesel pump does not start
Cause
Remedy
There is no fuel.
•
Fill the tank.
There is a battery failure.
•
Check the battery and
replace if necessary.
There is a diesel engine failure. •
Repair of replace the diesel
engine. See the installation
and operating instructions of
the diesel engine.
12.3 The thermal relay trips (only for jockey pumps)
Cause
Remedy
Too much energy consumption
due to defective motor winding.
•
Replace the motor. Contact
Grundfos Service.
The pump is under strain.
•
Dismantle and clean the
pump.
12.4 The flow rate of the pump set is not as desired
Cause
Remedy
There are air pockets in
the inlet pipe.
•
Replace the inlet pipe or
change its arrangement.
The inlet pressure is too low
(cavitation).
•
Restore the
correct inlet condition.
The inlet pipe is too narrow.
•
Check the correct sizing of
the inlet pipe.
The pipe is clogged.
•
Clean or replace the pipe.
The foot valve is clogged or
blocked.
•
Clean or replace the foot
valve.
The direction of
rotation is incorrect.
•
Restore the correct direction
of rotation.
The pump is clogged.
•
Clean the pump. See the
installation and operating
instructions of the pump.
Incorrect flowmeter installation. •
Check and correct
the installation.
There are air pockets in the
flowmeter.
•
Bleed air from the flowmeter.
The measurement flange of the
flowmeter is clogged.
•
Clean the measurement
flange.
12.5 Water hammer in the system
Cause
Remedy
Water hammer when the outlet
valves are closed.
•
Install additional diaphragm
tanks or a bigger diaphragm
tank.
Water hammer when the pump
set is stopped.
•
The foot valve closes
late. Replace the foot valve
with a more appropriate
model.
12.6 Leaks from the mechanical seal
Cause
Remedy
The mechanical
seal is damaged.
•
See the installation and
operating instructions of
the pump.
34
English (GB)
Summary of Contents for 99844392
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