Pfeiffer DUO 20 M User manual

Translation of the original instructions
Operating Instructions
EN
PK 0203 BEN/L (1208)
DUO 20 M, DUO 20 MC
Rotary Vane Pump

Table of contents
2
Table of contents
1 About this manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1 Validity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.2 Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2 Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.1 Safety precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.2 Protective equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.3 Proper use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.4 Improper use. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3 Transport and storage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.1 Transport. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.2 Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
4 Product description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
4.1 Product identification. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
4.2 Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
5 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
5.1 Setting up the pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
5.2 Connecting the vacuum side. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
5.3 Connecting the exhaust side. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
5.4 Connecting to the mains power supply . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
5.5 Filling up the operating fluid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
5.6 Operations monitoring (Option). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
6 Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
6.1 Before switching on the pump. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
6.2 Switching on the pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
6.3 Pumping condensable vapours. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
6.4 Switching off the pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
7 Maintenance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
7.1 Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
7.2 Changing the operating fluid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
7.3 Cleaning or changing the silencer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
8 Decommissioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
8.1 Shutting down for longer periods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
8.2 Re-starting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
8.3 Disposal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
9 Malfunctions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
9.1 Rectifying malfunctions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
10 Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
11 Spare parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
11.1 Spare parts packages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
12 Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
13 Technical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
13.1 Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Declaration of conformity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

About this manual
3
1 About this manual
1.1 Validity
This operating manual is for customers of Pfeiffer Vacuum. It describes the functioning
of the designated product and provides the most important information for safe use of
the unit. The description follows applicable EU guidelines. All information provided in this
operating manual refer to the current state of the product's development. The documen-
tation remains valid as long as the customer does not make any changes to the product.
Up-to-date operating instructions can also be downloaded from www.pfeiffer-vacu-
um.com.
Applicable docu-
ments
*also available via www.pfeiffer-vacuum.com
1.2 Conventions
Safety instructions The safety instructions in Pfeiffer Vacuum operating instructions are the result of risk
evaluations and hazard analyses and are oriented on international certification stan-
dards as specified by UL, CSA, ANSI Z-535, SEMI S1, ISO 3864 and DIN 4844. In this
document, the following hazard levels and information are considered:
DUO 20 M/MC Operating instructions
Declaration of Conformity Part of this document
Operating instructions for accessories (order-specifically) see section "accessories"*
DANGER
Imminent danger
Indicates an imminent hazardous situation that will result in death or serious injury.
WARNING
Possibly imminent danger
Indicates an imminent hazardous situation that can result in death or serious injury.
CAUTION
Possibly imminent danger
Indicates an imminent hazardous situation that can result in minor or moderate injury.
NOTICE
Command or note
Command to perform an action or information about properties, the disregarding of
which may result in damage to the product.

4
About this manual
Pictograph
definitions
Instructions in the
text
Work instruction: here you have to do something.
Abbreviations used C version: Corrosive gas version
Symbols used The following symbols are used consistently throughout in all illustrations:
Vacuum flange
Exhaust flange
Gas ballast valve
Power connection
Prohibition of an action or activity in connection with a source of danger,
the disregarding of which may result in serious accidents
Warning of a displayed source of danger in connection with operation of
the unit or equipment
Command to perform an action or task associated with a source of dan-
ger, the disregarding of which may result in serious accidents
Important information about the product or this document
V
G

Safety
5
2 Safety
2.1 Safety precautions
●Do not expose any body parts to the vacuum.
●Observe the safety and accident prevention regulations.
●Check regularly that all safety precautions are being complied with.
●Do not carry out any unauthorised modifications or conversions to the pumps.
●Depending on the operating and ambient conditions, the surface temperature of the
pumps may rise above 70 °C. Use suitable finger guards if necessary.
●When returning the pumps to us please note the instructions in the Service section.
The following safety instructions are only valid for the disassembly of the drive
system for a vacuum pump with a magnetic coupling:
●When disassembling the drive system from the pump housing, the strong magnetic
field may influence the function and operational reliability of electrical and electronic
devices.
●Persons with cardiac pacemakers must keep away from the magnetic coupling.
Danger to life!
–Minimum distance: 2 m!
●Disassembled magnetic couplings must be kept away from computers, data storage
media and other electronic components.
●Keep the disassembled components of the magnetic coupling separate at all times.
Danger of crushing!
●Do not allow any magnetised parts into the vicinity of the magnetic coupling. Danger
of injury!
2.2 Protective equipment
Determined situations concerning the handling of vacuum pumps require wearing of per-
sonal protective equipment. The owner, respectively the employer are obligated to pro-
vide adequate equipment to any operating persons.
Duty to inform
Each person involved in the installation, operation or maintenance of the vacuum pump
must read and observe the safety-related parts of these operating instructions.
The operator is obligated to make operating personnel aware of dangers originating
from the vacuum pump, the pumped medium and the entire system.
DANGER
Danger to health by hazardous substances during maintenance or installation
Depending on the process vacuum pumps, components or operating fluids can be con-
taminated by toxic, reactive or radioactive substances.
Wear adequate protective equipment during maintenance and repairs or in case of
reinstallation.
CAUTION
Risk of injury through hot surfaces
Vacuum pumps can become hot during operation.
Allow the pump to cool before maintenance and repairs.
If necessary wear protective gloves according to directive EN 420.

6
Safety
2.3 Proper use
●The vacuum pump may only be used to generate a vacuum.
●Installation, operating and maintenance regulations must be complied with.
●Other accessories, than those described in this manual, must not be used without the
agreement of Pfeiffer Vacuum.
2.4 Improper use
Improper use will cause all claims for liability and warranties to be forfeited. Improper use
is defined as usage for purposes deviating from those mentioned above, especially:
●pumping of corrosive gases (exception: pumps in C version)
●pumping of explosive media
●operation in potentially explosive areas
●pumping of gases containing impurities such as particles, dusts and condensate; note
the vapour compatibility levels of the pump
●pumping of substances that tend to sublime
●use of the vacuum pump to generate pressure
●pumping of liquids
●the use of operating fluids not specified by Pfeiffer Vacuum
●connection to pumps or units which are not suitable for this purpose according to their
operating instructions
●connection to units which have exposed voltage-carrying parts
WARNING
Increased noise emission!
Increased noise emission can occur within a limited area surrounding the vacuum
pump.
Provide noise protection or
wear hearing protection.
NOTICE
CE conformity
The manufacturer's declaration of conformity becomes invalid if the operator modifies
the original product or installs additional components.
Following installation into a plant and before commissioning, the operator must check
the entire system for compliance with the valid EU directives and reassess it accor-
dingly.

Transport and storage
7
3 Transport and storage
3.1 Transport
Transport instructions
Remove the locking cap from the vacuum and exhaust flange immediately before con-
necting!
– Check the protective strainer, paying attention to the O-ring.
Use only the handle or the crane eye on the top side of the pump to lift the pump.
– Is the pumps weight > 25 kg lift the pump by a crane.
Fig. 1: Transporting the pump
3.2 Storage
Check that all the openings on the pump are securely closed.
Store the pump in a cool, dry place; preferably at temperatures between -10 °C and
+40 °C.
– For a longer period of storage, seal the pump in a PE bag with drying agents en-
closed.
– For a period of storage longer than two years, it is recommended to change the op-
erating fluid before using the pump.

8
Product description
4 Product description
4.1 Product identification
To correctly identify the product when communicating with Pfeiffer Vacuum, always have
the information from the rating plate available and use it:
●Pump model and model number
●Serial number
●Type and amount of operating fluid
●Date of manufacture
Please find the voltage range and motor-related data on the separately attached motor
rating plate.
Fig. 2: Product identification on the rating plate
Scope of delivery ●Pump with motor (power cord/power switch --> dependent on the motor type)
●Operating fluid P3 (for standard pump)
●Cone strainer and centering ring with O-ring
●Locking cap for vacuum and exhaust flange
●Operating instructions
Variants
D-35641 Asslar
Mod.: DUO 10
Mod.-Nr.: PK D62 105 D
Ser.- Nr.: 3454440
S : max. 10 m /h
Oil : P3 1.0 l
Mass : 24 kg
n : 1800 1/min
(N )
2
3
max.
Made in Germany 2005/01
Pump type Pump versions
DUO 20 M Standard version of pump
DUO 20 MC C version of pump; differences from the standard version:
●Operating fluid F4
●Encapsulated can of the magnetic coupling at the pump system
●Vane material changed
●Gas ballast valve with dosable flushing gas connection
●Leak rate ≤1*10-5 hPa * l/s

Product description
9
4.2 Function
The vacuum pumps of the DuoLine®are dual stage rotary vane pumps and are used pri-
marily for rough and medium vacuum applications. The pumps are fitted with a hydrau-
lically controlled vacuum safety valve which, when the pump is at a stillstand, closes the
vacuum chamber vacuum tight and at the same time vents the pump. The integrated
magnetic coupling functions free of contact and friction. Therefore it is not subjected to
any mechanical wear and is completely maintenance free compared to a conventional
shaft feedthrough.
Fig. 3: Rotary Vane Pump DUO 20 M
1 Vacuum flange
2 Exhaust flange
15 Main switch
28 Casing
42 Gas ballast valve
80 Base plate
110 Sight glass
198 Operating fluid filler screw
198a Operating fluid drain screw
1198 2 1542
110 8 028198a

10
Installation
5Installation
5.1 Setting up the pump
Installation location Observe the following requirements when setting up the pump:
●Consider the load-bearing capacity of the installation site.
●Maximum installation altitude 2000 m (above mean sea level)
●Permissible ambient temperature: +12 ... 40°C
●Maximum relative humidity 85%
Fig. 4: Setting up the pump
Fill up with operating fluid before operating the first time (see p. 15, chap. 5.5).
– Amount and type according to rating plate
Always place the pump on a firm, even surface.
– The base frame has four holes for anchoring onto the base.
When installing the pump in a closed housing, ensure there is sufficient air circulation.
– Sight glass and gas ballast valve must be visible and readily accessible.
– Voltage and frequency information given on the motor rating plate must be visible.
5.2 Connecting the vacuum side
Remove locking cap from the vacuum flange;
– pay attention to the cone strainer and the respective O-ring in the intake port.
The connection between the pump and the vacuum chamber should be kept as short
as possible.
– Depending on the pump type, use metallic hoses or PVC hoses with flange con-
nections.
– Separators, filters etc. may be installed upstream to protect the pump (see acces-
sories). However, please observe the loss of pumping capacity due to the conduc-
tivity of the accessories.
5.3 Connecting the exhaust side
max. 10
°
> 35 mm
CAUTION
High pressure in the exhaust line!
Danger of damage to the seals and danger of the pump bursting.
Install the line without shut-off valves on the exhaust side.
If there is danger of a build-up of excess pressure (> 1500 hPa abs.) in the lines, ob-
serve all official accident prevention safety regulations.
If the exhaust gases are being extracted, the exhaust pressure must be at least
250 hPa greater than the pressure at the intake side.

Installation
11
Choose the cross-section of the exhaust line to be at least the size of the nominal
connection diameter of the vacuum pump's exhaust connection.
Piping to the pump must be suspended or supported.
– Physical forces from the piping system must not be allowed to act on vacuum
pumps.
Lay piping from the pump sloping downward so that no condensate can flow back into
the pump; otherwise fit a condensate separator.
– If an air trap is created in the system, then a device for draining condensation water
must be provided at the lowest point.
5.4 Connecting to the mains power supply
Depending on the pump type, different motor versions or mains voltages are possible:
●Single phase motor for fixed voltage with a built-in thermal protection switch, mains
switch and connecting cable.
●Single phase motor with switchable broad range voltage motor with a built-in thermal
protection switch and mains connection socket.
●Three phase motor (without switch and mains cable).
WARNING
Emission of toxic substances from the exhaust!
Danger of poisoning from emitted gases or vapours, which can be detrimental to health
and/or can pollute the environment, depending on the particular application.
Comply with the applicable regulations when working with toxic substances.
Only officially approved filter systems may be used to separate and remove these
substances.
DANGER
Voltage-bearing elements
Danger to life from electric shock.
The electrical connection can be carried out only by trained and authorised electrici-
ans.
Disconnect the power supply and secure it against being switched back on.
Ensure the system is adequately earthed.
WARNING
Danger of injury from moving parts!
After power failure or motor shutdown due to overheating, the motor may restart auto-
matically.
Secure the motor so that it cannot be switched on while any work is being performed
on the pump.
If necessary, dismantle the pump from the installation for inspection.
NOTICE
Excess voltage!
Danger of destroying the motor.
Power connections must comply with local regulations. Voltage and frequency infor-
mation given on the motor rating plate must correspond to the mains voltage and fre-
quency values.
To protect the motor and supply cable in case of malfunction, mains fuse protection
must be implemented.

12
Installation
Single phase broad
range voltage motor
The mains voltage must be determined on-site each time before the pump is installed
or moved to a different location.
Fig. 5: Connection diagram (terminal box)
Changing the voltage range
Disconnect the pump from the power supply.
Set the rocker switch "S" in the motor terminal box to the desired voltage range.
Fuse protection
To protect the motor in case of malfunction, carry out fuse protection in accordance
with the regional regulations.
– Select a fuse with slow characteristics.
The transmission power of the pump’s magnetic coupling is so great that there is
no overload protection for the motor.
NOTICE
Overvoltage!
An incorrect voltage range setting can damage the motor.
Disconnect the pump from the power supply.
Only change the voltage range when the pump is disconnected from the power
mains.
R Capacitor relay
S Voltage selector switch
T Thermal protection switch
U Mains switch
V Mains connection socket
Rocker switch in the terminal box for changing the voltage range
Switch position:
Voltage range: 200 ... 230 V/50 Hz
200 ... 240 V/60 Hz
100 ... 110 V/50 Hz
100 ... 120 V/60 Hz
P
B
T
R
S
U
V
J
T7 T3 T3 T1
T2 T8 T4 T4
CP
CD
2
3
1
B6
A5
A1
LN
B6
B2
B4
B2
A5
A3
A1

Installation
13
Three-phase motor The three-phase current motor circuit
The connections U1 - L2, V1 - L1 and W1 - L3 result in a clockwise rotation of the motor
shaft as seen looking towards the motor fan.
Delta Connection
The three coils are connected in series with the connection point connected to the mains.
The voltage of each coil is the same as the mains voltage whereas the mains current is
the cube root of the coil current. Delta connections are denoted by the symbol ∆. The
voltage between the mains supply lines is called mains voltage. The mains current is the
current which flows in the supply lines.
Fig. 6: Motor coil and connecting plate of Delta Connection (for low voltage)
Star Connection
The ends of the three coils are connected at the star center. The terminal voltage is the
cube root of the coil voltage; the mains and the coil current are the same. Star connec-
tions are denoted by the symbol Y.
Fig. 7: Motor coil and connecting plate of Star Connection (for high voltage)
Inspection of the direction of rotation
For pumps with three-phase motors, it is necessary to check the direction of rotation!
Remove the locking cap from the exhaust flange (if existing).
Switch the pump on briefly (from 2 to 3 sec.).
– The motor and motor fan must turn in a clockwise direction (see the arrow on the
support stand).
If the direction of rotation is incorrect: Swap two phase contacts at the connecting ca-
ble.
Fill up the operating fluid.
W2 U1
L1
V2 V1
W1 U2
L3
L2
W2 U2 V2
U1 V1 W1
L1
L2 L3
W2
U1
L1
V2
V1
W1
U2
L3
L2
W2 U2 V2
U1 V1 W1
L1
L2 L3
CAUTION
Operating fluids may leak out!
If the direction of rotation is incorrect, there is a danger that operating fluids may leak at
the vacuum flange.
Always check the direction of rotation before filling in operating fluid.

14
Installation
Motor protection
Pump motors equipped with PTC temperature sensors (3PTC) in the stator windings can
be connected to a PTC resistor tripping device for protection against overload. Other ap-
proved motor temperature monitoring can be used also by the operator.
Tripping devices store the shutdown event and need to be manually switched back on
again via the integrated RESET button or via the external RESET S3. Mains-ON is de-
tected as an automatic RESET.
Set up the connections so that the directional rotation indicated on the pump is main-
tained, regardless of the representations in the current flow diagram.
Fig. 8: Connection example for a three-phase AC motor with PTC resistor tripping device
USControl voltage
S1OFF button
S2ON button
S3RESET button, external
K1 Contactor
F1 ... F4 Fuses
T1... T3 PTC resistor sensor
H1 Tripping indicator
M Motor, 3-phase
1) Only for devices with two
relay outputs
2) Only for MSR type
3) Only for order no.:
P 4768 051 FQ
N
L1
M
3
L2
L3
F1 - F3
K1
10 11
AC 220 ... 240 V
Us F4
UVW
S1
S2
k1
K1
H1
S3
2)
A1 A2 T1 T2 Y2Y1 24 21 22 14 1211
2) 2) 1) 1) 1)
T1...T3
3)
NOTICE
Do not start with star/delta connection.
Always start motor directly.

Installation
15
5.5 Filling up the operating fluid
The type and amount of operating fluid should be visible on the pump's rating plate for
every rotary vane pump.
The delivery consignment for the standard pump contains sufficient operating fluid for
one filling. Pumps for special applications (e.g. for pumping corrosive gases) can be op-
erated with other operating fluids. These must be defined in accordance with Pfeiffer
Vacuum specifications before initial assembly and ordered separately.
Permissible operating fluids
●P3 (Standard operating fluid)
●F4 (Operating fluid for corrosive gas versions)
●D1 (for special applications and higher operating temperature)
– Final pressure of measurement, depending on the type of gas: < 5 ·10-2 hPa
Filling up the operat-
ing fluid
Unscrew operating fluid filler screw 198.
Fill up operating fluid.
– Correct filling level during operations: within the markings at the sight glass frame.
Fig. 9: Filling up the operating fluid
Screw in operating fluid filler screw 198.
Check operating fluid level only when the pump is warm and running; close
– vacuum flange and gas ballast valve to do so,
– Check operating fluid daily in non-stop operation, otherwise whenever the pump is
switched on. Refilling is possible when the pump is in final vacuum operation.
NOTICE
Use approved operating fluids only!
The use of operating fluids that have not been approved by Pfeiffer Vacuum shall result
in a limited warranty. In such cases, it is not possible to guarantee that product-specific
performance data will be achieved.
Prior consultation is required before using other application-specific operating fluids.
max
.
min.
198
WARNING
Toxic vapours!
Danger of poisoning when igniting and heating synthetic operating fluids (e.g. F4/F5)
above 300°C.
Observe the application instructions.
Do not allow operating fluid to make contact with tobacco products; observe safety
precautions when handling chemicals.

16
Installation
5.6 Operations monitoring (Option)
A pressure switch can be installed on the side of the support to monitor the operating
fluid pressure of the rotary vane pump during operations. By pressure drop and when the
pump is at rest, the contact of the pressure switch opens. The signal can be used to con-
trol external valves.
Fig. 10: Installation location and circuit diagram of pressure switch
Switch off the pump.
Unscrew and remove locking screw 142 on the support.
Remove protective cover of the pressure switch and screw in with O-ring.
Make electrical connections at the pressure switch.
Reassemble the protective cover.
Switching voltage: 5 ... 250 Volt (potential-free)
Current, max. 2 Amp.
Protection class IP 55
1 + 2 closers = pressureless open
1
2

Operation
17
6 Operation
6.1 Before switching on the pump
Check the operating fluid level in the sight glass.
Compare the voltage and frequency information on the rating plate with the mains volt-
age and frequency values.
Check that the exhaust connection allows free flow (max. permissible pressure 150
kPa absolute).
– Activate the shut-off valves in such a way that they open before or at the same time
as the pump is started.
Protect the pump sufficiently from taking in contaminants by means of suitable precau-
tions (e.g. dust filters); if necessary, check operating fluid regularly or replace at short-
er intervals.
6.2 Switching on the pump
The pump can be switched on in any pressure range between atmospheric and
ultimate pressure.
No special precautions are necessary when pumping dry gases. In order to attain the
lowest possible ultimate pressures, the gas ballast valve should be closed.
Switch on pump at main switch 15.
Switch on the pump with the vacuum flange closed and allow to warm up for 30 min-
utes.
6.3 Pumping condensable vapours
Should the process gases contain condensable gases present at high percentages, the
rotary vane pump must be operated with gas ballast (i.e. with an open gas ballast valve).
Gas ballast valve,
standard version
To avoid condensation in the pump when pumping condensable vapours, air is periodi-
cally fed into the working chamber at the beginning of the compression phase via the gas
ballast valve 42.
The gas ballast valve is closed when turning to the right to position 0 and open when turn-
ing to the left to position 1. Intermediate settings are not possible.
CAUTION
Hot surface!
Danger of burns if hot parts are touched. Depending on the operating and ambient con-
ditions, the surface temperature of the pump may rise above 70 °C.
In this case, use suitable finger guards.
NOTICE
Bad final vacuum and damage to the pump!
Danger of condensation and corrosion due to exceeding the water vapour compatibility
during operation without gas ballast or in case of insufficient supply of flushing gas.
Only pump vapours when the pump is warm and the gas ballast valve is open.
When the process has been completed, allow the pump to continue running for
about 30 minutes with the vacuum flange closed and the gas ballast open for ope-
rating fluid regeneration purposes.

18
Operation
Fig. 11: Standard version 42 of gas ballast valve
Gas ballast valve with
flushing gas connec-
tion (option)
If the pumping process requires the use of flushing gas, a supply hose can be connected
at the gas ballast valve.
Fig. 12: Gas ballast valve with flushing gas connection
Connect flushing gas at the flushing gas connection.
Set flushing gas pressure; maximum pressure 1.5 bar (absolute).
– Select the type and amount of flushing gas depending on the process; consult Pfei-
ffer Vacuum if necessary.
0
0
1
1
0
1
0
1
NOTICE
Flushing gas pressure higher than allowed endangers the operational reliability
of the pump.
The power input of the pump, the temperature and the ejection of operating fluid will in-
crease.
Observe the maximum permissible flushing gas pressure.
Set the amount of flushing gas on site.

Operation
19
6.4 Switching off the pump
The pump can be switched off in any pressure range.
Rotary vane pumps have an integrated safety valve on the intake side. If the differential
pressure between the exhaust side and the intake side is ≥250 hPa, then the valve clos-
es automatically and vents the pump when the pump is switched off.
Switch the pump off at the mains switch or disconnect from the mains in a secure man-
ner.
Venting the vacuum
chamber
Maintaining the vac-
uum in the chamber
NOTICE
Danger of backflow of operating fluid into the intake line!
Contamination of the connected vacuum system!
Vent the vacuum chamber within 30 s, regardless of the chamber size.
For a longer venting process, use an additional shut-off valve and shut off the intake
line after switching off the pump.
NOTICE
Danger of backflow of operating fluid into the intake line!
Contamination of the connected vacuum system!
Because the safety valve of the pump is not suitable for longer-term sealing, install
an additional shut-off valve in the intake line.
Shut off the intake line immediately after switching off the pump.

20
Maintenance
7 Maintenance
7.1 Precautions
Turn off the vacuum pump, vent to atmospheric pressure and allow to cool, if neces-
sary.
Disconnect the drive motor from the mains and secure it so that it cannot be switched
on.
Only dismantle the pump as far as necessary in order to repair defects.
Dispose of used operating fluid in compliance with local regulations.
When using synthetic operating fluids or working with toxic substances or substances
contaminated with corrosive gases, the relevant instructions governing their use must
be observed.
Use only alcohol or similar agents for cleaning pump parts.
DANGER
Strong magnetic field in the vicinity of the drive system!
Danger to life for persons with cardiac pacemakers when the drive system is disassem-
bled.
Persons with cardiac pacemakers must not enter the area (≤2m) of the magnetic
field.
Rooms in which open couplings are accessible must be identified: ’’ No trespassing
for persons with heart pacemaker’’!
Disassembled magnetic couplings must be kept away from computers, data storage
media and other electronic components.
WARNING
Danger of injury from moving parts!
After power failure or motor shutdown due to overheating, the motor may restart auto-
matically.
Secure the motor so that it cannot be switched on while any work is being performed
on the pump.
If necessary, dismantle the pump from the installation for inspection.
WARNING
Pump parts may be contaminated from pumped media!
Danger of poisoning due to contact with harmful substances.
Decontaminate the pump before carrying out any maintenance work.
In the event of contamination, take suitable safety precautions to prevent your health
from being harmed by any dangerous substances.