Pfeiffer DUO 3 - Tbl. 7: Troubleshooting for Rotary Vane Pumps

Problem Possible causes Remedy
Vacuum pump switches off
after a while after being
started
● Thermal protection switch
of the motor has triggered
● Determine and eliminate the
cause of overheating.
● Allow the motor to cool down.
● Mains fuse triggered due
to overload (e.g. cold
start)
● Bring vacuum pump to permissi-
ble ambient temperature range.
● Exhaust pressure too high ● Check exhaust line outlet open-
ing and exhaust side accesso-
ries.
Vacuum pump does not
reach the specified final
pressure
● Measurement result dis-
torted
● Check the measurement instru-
ment.
● Check the final pressure without
system connected.
● Vacuum pump or con-
nected accessory conta-
minated
● Clean the vacuum pump.
● Check the components for con-
tamination.
● Operating fluid contami-
nated
● Operate the vacuum pump for an
extended period of time with gas
ballast valve open, or change the
operating fluid.
● Operating fluid level too
low
● Top up the operating fluid.
● Leak in system ● Locate and eliminate the leak.
● Vacuum pump is dam-
aged
● Contact Pfeiffer Vacuum Serv-
ice.
Pumping speed of vacuum
pump too low
● The intake line is not suit-
ably dimensioned
● Make sure that connections are
short and cross sections ade-
quately dimensioned.
● Exhaust pressure too high ● Check exhaust line outlet open-
ing and exhaust side accesso-
ries.
Loss of operating fluid ● Casing seal is leaking ● Check and replace the seal.
● Radial shaft seal ring
(RSSR) leaking – not ap-
plicable to vacuum pumps
with magnetic coupling
● Check and replace the RSSR
● Check and replace the associat-
ed bushing also.
● Operational operating flu-
id loss – no oil mist filter
● Install ONF/OME.
Unusual noises during op-
eration
● Noise reduction is conta-
minated
● Clean the noise reduction or re-
place it.
● Pumping system is conta-
minated or damaged
● Clean and maintain the vacuum
pump.
● Contact Pfeiffer Vacuum Serv-
ice.
● Motor bearing is faulty ● Change the motor.
● Contact Pfeiffer Vacuum Serv-
ice.
Tbl. 7: Troubleshooting for rotary vane pumps
Malfunctions
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