Chemically-resistant Laboratory pump N820.18 EX / N840.18 EX
Flow rate, pressure or vacuum too low
The pump does not reach the output stated in the technical data or data
sheet.
Cause
Replaced diaphragm
and valve plates/seals.
Rotary/push knob is
not set to max. speed.
Gas ballast still open.
Pump is switched on and not running; status display is not illuminated
Cause
Pump is not connected
to the electrical mains.
No voltage in the elec-
trical mains.
Pump is switched on and not running; status display flashes red (50% ON,
50% OFF)
Cause
Pump has overheated,
overtemperature pro-
tection has tripped.
Translation of Original Operating Instruction, KNF 317428-317425 05/21
Fault remedy
à
Ensure that shim rings were fitted on the diaphragm
thread.
à
Check the hoses for leaks.
à
If necessary, carefully tighten the outer screws of
the pressure plate crosswise.
à
Set the rotary/push knob to max. speed.
à
Connect the gas ballast.
Tab.23: Troubleshooting: Flow rate, pressure or vacuum too low
Fault remedy
à
Connect the pump to the electrical mains.
à
Check the circuit breaker for the room and switch it
on if necessary.
Tab.24: Troubleshooting: Pump is switched on and not running; sta-
tus display is not illuminated
Fault remedy
à
Pull power cable of the pump out of the socket.
à
Allow the pump to cool.
à
Determine the cause of the overheating and rectify.
Tab.25: Troubleshooting: Pump is switched on but not running; sta-
tus display is flashing red
Troubleshooting
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