10 Troubleshooting
Problem
Possible causes
Remedy
Pump not achieving ultimate pres-
sure. (no throughput)
Deposits in the pump
Clean and check diaphragm
heads
Condensate in the pump
Operate pump for a longer period
of time under atmospheric pres-
sure
In-process steam formation
Check process parameters
Valves/diaphragms soiled/
faulty
Clean/replace valves/diaphragms
Small flange connection
centering ring inserted in-
correctly
Check connection
Long, thin vacuum line
Choose a line with a larger cross
section.
Leak in system
Fix leak
Check pump directly, connect
measurement instrument directly
to pump inlet
Unusual noises during operation
Valves/diaphragms faulty
Replace valves/diaphragms
Dirt in suction chamber
Cleaning the suction chamber
Silencer loose or missing
Check or replace silencer
Motor fan defective
Replace motor fan
Connection rod or motor
bearing defective
Contact Pfeiffer Vacuum Service
Pump does not start up.
No mains voltage
Check mains voltage
Check mains fuse
Insert mains plug
Phase failure
Check fuse
Thermal winding protection
has triggered. (Motor over-
loaded)
Allow motor to cool down and
switch mains switch off and on
again.
Ambient temperature too
low
Warm up pump
Valves/diaphragms soiled/
faulty
Clean/replace valves/diaphragms
Overpressure in exhaust
line
Open exhaust line
Pump switches off.
Diaphragm bonded
Clean pump
Mains voltage incorrect
Correct according to rating plate
Motor contactor tripped.
Pump overheated
Switch off pump or disconnect
mains plug.
Allow pump to cool down.
Determine and eliminate cause
of overheating.
Pump blocked or connection rod
stiff
Contact Pfeiffer Vacuum Service
Troubleshooting
30/40
