Pfeiffer DUO 20 M, Operating Instructions Manual

Page: 27 / 35

Malfunctions
27
9.1 Rectifying malfunctions
Problem Possible causes Remedy
Pump will not start up No mains voltage or voltage does
not correspond to the motor data
Check mains voltage and mains fuse protec-
tion; check motor switch
Pump temperature too low Warm up pump to > 12°C
Thermal protection switch has re-
sponded Detect and fix cause of overheating; allow
pump to cool off if necessary
Pump system dirty Clean pump; contact Pfeiffer Vacuum Ser-
vice if necessary
Pump system damaged Clean and overhaul pump; contact Pfeiffer
Vacuum Service if necessary
Motor defective Replace motor
Pump switches off af-
ter a while after being
started Thermal protection switch of the
motor has responded Detect and fix cause of overheating; allow
motor to cool off if necessary
Mains fuse protection triggered
due to overload (e.g. cold start) Warm up pump
Exhaust pressure too high Check opening of exhaust line and exhaust
accessories
Pump does not attain
final pressure Measurement reading is false Check gauge, check final pressure without
installation connected
Pump or connected accessories
are dirty Clean pump and check components for con-
tamination
Operating fluid dirty Operate pump for a longer period with gas
ballast valve open or change operating fluid
Leak in system Repair leak
Operating fluid filling level too low Top off operating fluid
Pump damaged
Contact Pfeiffer Vacuum Service
Pumping speed of
pump too low Intake line not well-dimensioned Keep connections as short as possible and
see that cross-sections are sufficiently di-
mensioned
Exhaust pressure too high Check opening of exhaust line and exhaust
accessories
Loss of operating fluid Swivel gasket leaky Check tightness; replace gasket if neces-
sary
Operational loss of operating fluid If necessary, install oil mist filter and oil re-
turn unit
Unusual operating
noises Silencer dirty Clean or replace the silencer;
(see p. 24,
chap. 7.3)
Damage to the pump system Clean and overhaul pump; contact Pfeiffer
Vacuum Service if necessary
Motor bearing defective Replace motor; contact Pfeiffer Vacuum
Service if necessary
NOTICE
Service work should be carried out by qualified personal only!
Pfeiffer Vacuum is not liable for any damage to the pump resulting from work carried out
improperly.
 Take advantage of our service training programs; additional information at www.pfeif-
fer-vacuum.com.
 Please state all the information on the pump rating plate when ordering spare parts.