Troubleshooting - KNF NF 10 DC series Operating Instructions Manual

Diaphragm–Liquid pump NF 10
Pump does not pump
Possible cause
Pump not connected to mains
power supply.
Power supply is not switched
on.
Connections or tubing are
blocked
External valve is closed or filter
is blocked.
Diaphragm or valves are worn
out.
Pump is not priming / sucking
Possible cause
Pump is not connected suction
side.
Liquid in the container is too
low.
Hose connections are not tight.
System valve is closed or filter
is blocked.
The vacuum is too small for the
suction height.
Valves are blocked by particles
Pump head materials are not
resistant to the liquids being
pumped.
Inlet and outlet tubes have been
wrongly connected.
KNF Flodos AG BA_NF10_EN_05_069219
Operating and Installation Manual
9.

Troubleshooting

For pumps with alternating current motors:
Life threat by electric shock
 Before working on the pump separate the pump
from the power supply.
GEFAHR
 Ensure that the pump is de-energised.
Corrective action
 Connect pump to mains supply.
 Switch on power supply.
 Check tubing lines and connections.
 Remove blockage.
 Check valve timing and filters.
 Replace diaphragm and valves
(See paragraph 8.3).
Tab. 16
Corrective action
 Check the arrows on the pump head indicating flow
direction.
 Fill container.
 Check for tightness – use clamp to ensure a good fit.
 Open the valve.
 Clean / replace filter.
 Reduce suction height.
 Clean the pump head (see section 8.2).
 Check compatibility lists and choose suitable version.
 Check the arrows on the pump head indicating flow
direction
Tab. 17
Troubleshooting
20