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"
Tighten the screw connections.
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 special dosing head
>> Contact manufacturer
No stroke movement
observed
Dosing pump set to zero stroke.
Set the stroke length adjusting knob cor-
rectly.
Diaphragm return spring broken. Replace the spring.
Power supply interrupted.
Switch on power supply.
Dosing pump delivery
rate too high
Pressure on suction side too
high (pump siphoning).
Install a pressure control valve on the
discharge line.
Heavy leakage at
piston
Packing not tightened strong
enough.
Tighten gland stud carefully.
Piston has longitudinal grooves
due to normal wear.
Replace piston and packing.
See also section 12, Maintenance.
Excessive wear due to abrasive
medium.
Replace PTFE packing with Aramid packing.
Dosing pump very
noisy.
Roller bearing defective.
Replace the roller bearing.
No oil in the gearing, or too little
Top up the oil as described in "Mainte-
nance".
Motor hums and
does not start.
Wrongly connected.
Check electrical wiring.
Capacitor defective, wrong size
or connected incorrectly.
Connect the capacitor correctly or replace.
Pressure too high.
Check the process.
Alarm states indi-
cated by red LEDs on
the display.
Low level alert
Level main alarm
Internal error
Check functions as described in chapter 8
(FEDOS DX Operation).
The dosing pump
switches off auto-
matically.
The dosing pump has been
disconnected from the power
supply in an uncontrolled way.
Use only an external switch-off to switch the
pump on/off. See paragraph 7.4 and 8.3
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 | Operating Manual FEDOS E/DX |
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