Troubleshooting
Diaphragm pump N820.18 CN / N840.18 CN
38
Translation of Original Operating Instruction, KNF 317428-338560 06/22
11 Troubleshooting
DANGER
Danger: electric shock can be life-
threatening.
à
All work on the pump may only be
performed by an authorized spe-
cialist.
à
Before working on the pump: Dis-
connect the pump from the power
supply.
à
Check and ensure that no voltage
is present.
à
Check the pump (see following tables).
Pump not delivering
Cause
Troubleshooting
No voltage in the elec-
trical mains.
à
Check the circuit breaker for the room and switch it
on if necessary.
Overtemperature pro-
tection of the pump has
tripped
à
Disconnect the pump from the electrical mains.
à
Allow the pump to cool.
à
Determine the cause of the overheating and rectify.
Connections or lines
are blocked.
à
Check the connections and lines.
à
Remove the blockage.
External valve is closed
or filter is clogged.
à
Check external valves and filters.
Condensate has col-
lected in the pump
head.
à
Separate the source of the condensate from the
pump.
à
Flush the pump with air at atmospheric pressure for
a few minutes (if necessary for safety reasons: with
an inert gas).
Diaphragms or valve
plates/seals are worn.
à
Replace the diaphragms and the valve plates/seals
(see Chapter Replacing diaphragm and valve
plates).
Tab.16: Troubleshooting: Pump not delivering
