13. Troubleshooting
Problem
Possible cause
Remedy
Dosing pump
not delivering
or output too
low.
Valves leaking or blocked.
Clean the valves and vent the dosing
pump.
See also "Start-up"
Valves incorrectly installed.
Reassemble the valves.
Ensure that the valve balls are located
above the valve seats.
Suction valve or suction line leaking or
blocked.
Clean or seal the suction line.
Suction lift too high.
Set the dosing pump at the inlet.
Install the pulsation damper on the
suction side.
Install a priming aid.
Viscosity too high.
Install spring-loaded valves.
Increase the pipe diameter.
Use a special dosing head.
>> Contact manufacturer
No stroke
movement
Dosing pump set to zero stroke.
Set the stroke length adjusting knob
correctly.
Diaphragm return spring broken.
Replace the spring.
Fuse blown. No LED is lit.
Check power supply voltage, contact
service.
Power supply interrupted.
Switch on power supply.
Solenoid defective.
Check coil resistance and isolation;
replace solenoid, if required.
Red "Empty"
indicator.
Chemical tank empty. Level monitoring con-
nector or dummy plug incorrectly inserted.
Cable break.
Fill supply tank and check lines.
Frequent
diaphragm
failures.
No support plate. See "Maintenance"
Install new diaphragm with support plate/
spacer. When replacing the diaphragm,
check if deflector plate or diaphragm rod
have been corroded by chemical.
Diaphragm not screwed up to end stop on
diaphragm rod.
Screw a new diaphragm up to the
end stop. Support plate/spacer must
be clamped between diaphragm and
diaphragm rod.
System backpressure too high. (measured
at discharge connection of dosing pump).
Inspect the system. Clean blocked injec-
tion nozzle. Install pulsation dampers to
reduce pressure peaks if pipes are too
long.
Check safety valves.
Media sediment in dosing head.
Clean the dosing head.
Dosing pump
delivery rate
too high
(Pump siphon-
ing)
Pressure on suction side too high.
Install pressure control valve or suction
pressure regulator.
Stroke stop shifted.
Readjust stop.
Stroke frequency too high.
Reduce stroke frequency.
If the problem cannot be solved with the above remedies, please return the dosing pump to the factory or contact our After-
Sales Service for further assistance. Repairs will be carried out immediately.
Troubleshooting | Operation & Maintenance Instructions |
35
