BUSCH COBRA NS 0070-0600 C User manual

Instruction Manual
COBRA ATEX
Dry Screw Vacuum Pumps
NS 0600 C (water-cooled version)
0870219588/-0000_en / Original instructions / Modifications reserved 20/11/2019
Ateliers Busch S.A.
Zone industrielle, 2906 Chevenez
Switzerland

Table of Contents
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Table of Contents
1 Safety........................................................................................................................... 4
2 Product Description ..................................................................................................... 5
2.1 Operating Principle............................................................................................... 6
2.2 Application ........................................................................................................... 6
2.3 Start Controls .......................................................................................................6
2.4 Standard Features................................................................................................. 6
2.4.1 Water Cooling ...........................................................................................7
2.4.2 Sealing Systems .........................................................................................7
2.4.3 Barrier Gas System.....................................................................................7
2.4.4 Resistance Thermometer............................................................................7
2.5 Optional Accessories............................................................................................. 7
2.5.1 Nitrogen Panel...........................................................................................7
2.5.2 Terminal Box..............................................................................................8
2.5.3 Silencer......................................................................................................8
2.5.4 Pressure Transmitter ..................................................................................8
2.6 Explanation of ATEX Classification ........................................................................8
2.6.1 ATEX Nameplate........................................................................................8
2.7 Safety concept...................................................................................................... 8
2.7.1 ATEX Classifications and Associated Accessories ........................................9
2.7.2 P&ID "Piping and Instrumentation Diagram" ............................................9
3 Transport ..................................................................................................................... 11
4 Storage......................................................................................................................... 11
5 Installation................................................................................................................... 12
5.1 Installation Conditions .......................................................................................... 12
5.2 Connecting Lines / Pipes ......................................................................................13
5.2.1 Suction Connection....................................................................................13
5.2.2 Discharge Connection................................................................................13
5.2.3 Cooling Water Connection ........................................................................14
5.2.4 Barrier Gas System Connection ..................................................................15
5.3 Earth Connection.................................................................................................. 16
5.4 Filling Oil..............................................................................................................16
5.5 Filling Cooling Liquid ............................................................................................ 18
5.6 Electrical Connection ............................................................................................18
5.6.1 Wiring Diagram Three-Phase Motor (Pump Drive).....................................19
5.7 Electrical Connection of the Monitoring Devices ................................................... 20
5.7.1 Wiring Diagram Resistance Thermometer ..................................................21
5.7.2 Wiring Diagram Pressure Transmitter.........................................................22
5.7.3 Wiring Diagram Flow Switch......................................................................22
5.8 Flowchart ............................................................................................................. 23
6 Commissioning............................................................................................................ 24
6.1 Conveying Condensable Vapours ......................................................................... 25
7 Maintenance................................................................................................................ 25
7.1 Maintenance Schedule.......................................................................................... 26
7.2 Oil Level Inspection .............................................................................................. 27
7.3 Cooling Liquid Level Inspection ............................................................................27
7.4 Oil Change...........................................................................................................27
7.5 Cooling Liquid Change ......................................................................................... 30
7.6 Calibration Procedure of the Electrical Devices ..................................................... 31

Table of Contents
0870219588_NS0600C_WCV_Ex_-0000_IM_en 3
7.6.1 Procedure A...............................................................................................31
7.6.2 Procedure C...............................................................................................31
7.6.3 Procedure E ...............................................................................................31
8 Overhaul...................................................................................................................... 32
9 Decommissioning ........................................................................................................ 32
9.1 Dismantling and Disposal...................................................................................... 32
10 Spare Parts................................................................................................................... 33
11 Troubleshooting........................................................................................................... 34
12 Technical Data ............................................................................................................. 36
13 Cooling Liquid ............................................................................................................. 36
14 Oil ............................................................................................................................... 36
15 EU Declaration of Conformity ...................................................................................... 37

1 | Safety
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1 Safety
Prior to handling the machine, this instruction manual should be read and understood. If
anything needs to be clarified, please contact your Busch representative.
Read this manual carefully before use and keep for future reference.
This instruction manual remains valid as long as the customer does not change anything
on the product.
The machine is intended for industrial use. It must be handled only by technically trained
personnel.
Always wear appropriate personal protective equipment in accordance with the local
regulations.
The machine has been designed and manufactured according to state-of-the-art meth-
ods. Nevertheless, residual risks may remain. This instruction manual highlights potential
hazards where appropriate. Safety notes and warning messages are tagged with one of
the keywords DANGER, WARNING, CAUTION, NOTICE and NOTE as follows:
DANGER
... indicates an imminent dangerous situation that will result in death or serious injuries if
not prevented.
WARNING
... indicates a potentially dangerous situation that could result in death or serious injuries.
CAUTION
... indicates a potentially dangerous situation that could result in minor injuries.
NOTICE
... indicates a potentially dangerous situation that could result in damage to property.
NOTE
... indicates helpful tips and recommendations, as well as information for efficient and
trouble-free operation.

Product Description | 2
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2 Product Description
IN
MTBOFP
CLF EB OFP
CLV
ODP
CWOPHE
SV
OSG
MP
CLP
CLD OUT
EB
OUT
PMR
NP1 NP2
CWI
SI
OSG ODP, MP
TSA+/0104
MP
PHE Plate heat exchanger CLD Cooling liquid drain plug
CLF Cooling liquid fill plug CLP Cooling liquid pump
CLV Cooling liquid vent plug EB Eye bolt
CWI Cooling water inlet CWO Cooling water outlet
IN Suction connection MP Magnetic plug
MTB Motor terminal box NP Nameplate
ODP Oil drain plug OFP Oil fill plug
OSG Oil sight glass OUT Discharge connection
PMR Plug for manual rotation of rotors SI Silencer
SV Safety valve TSA Resistance thermometer
NOTE
Technical term.
In this instruction manual, we consider that the term ‘machine’ refers to the ‘vacuum
pump’.

2 | Product Description
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2.1 Operating Principle
The machine works on the one-stage, twin-screw pump principle.
Two screw rotors are rotating inside the cylinder. The pumped medium is trapped
between the cylinder and screw chambers, compressed, and transported to the gas out-
let. During the compression process, the two screw rotors do not come into contact with
each other nor with the cylinder. There is no need for a lubrication or an operating fluid
in the compression chamber.
2.2 Application
The machine is intended for the suction of air and other dry, non-aggressive and non-
toxic gases.
Explosive gases and vapour mixtures can be drawn according to the scope of the Direct-
ive ATEX 2014/34/EU.
The machine is intended for suction of explosive gases according to the data given on
the nameplate of the machine (NP), see Explanation of ATEX Classification [►8].
Conveying of other media leads to an increased thermal and/or mechanical load on the
machine and is permissible only after a consultation with Busch.
The machine is not intended for the placement in a potentially explosive environment ac-
cording to the data given on the nameplate of the machine (NP), see Explanation of
ATEX Classification [►8].
The machine is capable of maintaining ultimate pressure, see Technical Data [►36].
The machine is suitable for continuous operation.
Permitted environmental conditions, see Technical Data [►36].
2.3 Start Controls
The machine comes without start controls. The control of the machine is to be provided
in the course of installation.
The machine can be optionally equipped with a starter unit or a variable-frequency drive.

Product Description | 2
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2.4 Standard Features
2.4.1 Water Cooling
The machine is cooled by a cooling liquid circuit in the cylinder cover and cylinder.
The cooling liquid pump (CLP) allows a recirculating flow in the cooling liquid chamber.
The cooling liquid is cooled by a plate heat exchanger (PHE) which must be connected to
the water main.
2.4.2 Sealing Systems
The machine is equipped with labyrinth seals on the motor side and suction side.
Sealing systems prevent the process gas going to the bearings chambers.
The sealing systems efficiency must be improved with a barrier gas system, see Barrier
Gas System [►7].
2.4.3 Barrier Gas System
The barrier gas system allows the supply of compressed air or nitrogen into the motor
side shaft seals in order to improve the sealing efficiency.
2.4.4 Resistance Thermometer
The resistance thermometer monitors the A-side oil temperature of the machine. A
second resistance thermometer might be installed to monitor the exhaust gas tempera-
ture.
Warning and trip signals must be set, see Wiring Diagram Resistance Thermometer
[►21].
2.5 Optional Accessories
NOTE
Depending on the ATEX classification of the machine, some of the following accessories
may be mandatory, see ATEX Classifications and Associated Accessories [►9].
2.5.1 Nitrogen Panel
The nitrogen panel fitted to the base frame allows the supply of nitrogen to a number of
different points on the machine.
Each device consists of a solenoid valve to open or close the gas circuit, a pressure regu-
lator and a flow meter to adjust pressure and volume flow separately.
The following devices are available:
– The barrier gas system for sealing systems on motor side. This device is equipped
with a flow switch integrated to the flow meter to switch off the machine if the ni-
trogen volume flow drops below the minimum set flow value.
– The purge gas system fitted at the inlet flange allows to flush the machine after use
or during operation. The nitrogen is fed into the inlet flange.

2 | Product Description
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2.5.2 Terminal Box
The machine can be optionally equipped with one or two terminal boxes. All electrical
devices, except the motor, are already wired to the terminal box.
2.5.3 Silencer
A silencer at the discharge connection (OUT) can be provided to reduce the exhaust gas
noise.
2.5.4 Pressure Transmitter
The pressure transmitter monitors the gas pressure at the discharge connection (OUT).
Warning and trip signals must be set, see Wiring Diagram Pressure Transmitter [►22].
2.6 Explanation of ATEX Classification
The ATEX classification is written on the nameplate of the machine (NP), see below a
marking example:
Inside (i)
Outside (o)
II 3G Ex h IIC T2 Gc X
No ATEX zone
Explosion group inside the machine
Equipment category for explosive gases inside the machine
Equipment group II (not for mining application)
Explosion protection inside the machine
Design approved according to ATEX Directive
Temperature class inside the machine
Equipment protection level
(T2=300°C) ; (T3=200°C) ; (T4=135°C)
Type of protection
Special conditions for operation*
* The specific operating conditions are determined in this instruction manual.
2.6.1 ATEX Nameplate
The machine has two different nameplates:
– A nameplate (NP1) is fixed on the base frame of the machine with the ATEX marking
inscription.
– A second nameplate (NP2) is fixed on the machine stage (module) identifying that
the stage is suitable for ATEX certified machine.
This allows the preservation of the machine ATEX certification if the machine stage
should be replaced.
2.7 Safety concept
WARNING
Misinterpretation of the ATEX instructions.
Risk of severe injury!
Risk of explosion!
• Make sure that the recommendations described in this manual correspond to the
ATEX marking written on the nameplate (NP).
• If anything needs to be clarified, please contact your Busch representative.

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The safety concept is based on the prevention of sparks and excessive temperatures by
means of various accessories.
The monitoring devices must be integrated into the system control such that operation
of the machine will be inhibited if the safety limit values are exceeded.
2.7.1 ATEX Classifications and Associated Accessories
The following table defines the obligatory accessories depending on the ATEX classifica-
tion.
TSA+
/0104
PSA+/0301
ECP
TSA+
/0103
FS-
/0501
PS+/0301
XX
( )
(i) II 3G Ex h IIC T2 Gc X
(o) No ATEX zone
X
ATEX classification
option option option motor
Barrier
gas
ECP Pump earth connection FS Flow switch
PSA Pressure transmitter PS Pressure switch
SA Vibration transmitter TSA Resistance thermometer

2 | Product Description
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2.7.2 P&ID "Piping and Instrumentation Diagram"
M
MV6
0201
LS-
0202
LS-
TSA+
0104
MV4
MV2
MV5
FS-
0501
FME
FME
FME
FS-
0503
FS-
0504
FLV
NRV
NRV
GC
NIF
MAN
IN
OUT
CPL
MOT
TSA+
0103
GB
CWO
CWI
MV7
PHE
CLP
TTV
55°C
SI
NRV
MAN
MAN
IS
PRV
PRV
PRV
G1/4
G1/2
G1/2
DN100 ISO-K
DN100 PN16
DN100 ISO-K
DN100 PN16
PSA+
0301
PS+
0301
or
P&ID
= optional
Barrier gas system
Purge gas system
Dilution gas system
Flushing liquid device
Air
CLP Cooling liquid pump CPL Coupling
CWI Cooling water inlet CWO Cooling water outlet
FLV Flushing liquid vessel FME Flow meter
FS Flow switch GB Gas ballast valve
GC Gas connection IN Suction connection
IS Inlet screen LS Level switch
MAN Manometer MOT Motor
MV Solenoid valve NIF Nitrogen inlet filter
NRV Non-return valve OUT Discharge connection
PHE Plate heat exchanger PS Pressure switch
PSA Pressure transmitter SI Silencer
TSA Resistance thermometer TTV Three-way thermostatic valve

Transport | 3
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3 Transport
WARNING
Suspended load.
Risk of severe injury!
• Do not walk, stand or work under suspended loads.
WARNING
Lifting the machine using the motor eye bolt.
Risk of severe injury!
• Do not lift the machine using the eye bolt fitted to the motor. Only lift the machine as
shown.
NOTICE
In case the machine is already filled with oil.
Tilting a machine that is already filled with oil can cause large quantities of oil to in-
gress into the cylinder.
• Drain the oil prior to every transport or always horizontally transport the machine.
• Make sure that the eyebolt (EB) is in faultless condition, fully screwed in and tightened
by hand.
Machine weight:
see the technical data or the nameplate (NP)
• Check the machine for transport damage.
If the machine is secured to a base plate:
• Remove the machine from the base plate.
4 Storage
• Seal all apertures with adhesive tape or reuse provided caps.
If the machine is to be stored for more than 3 months:
• Wrap the machine in a corrosion inhibiting film.
• Store the machine indoors, dry, dust free and if possible in original packaging
preferably at temperatures between 5 ... 55 °C.

5 | Installation
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5 Installation
5.1 Installation Conditions
WARNING
The installation conditions are not respected in an ATEX environment.
Risk of severe injury!
Risk of explosion!
• Take care that the installation conditions are met.
NOTICE
Use of the machine outside of the permitted installation conditions.
Risk of premature failure!
Loss of efficiency!
• Take care that the installation conditions are fully complied with.
• Make sure that the environment of the machine complies with the ATEX classification
of the machine according to the data given on the nameplate of the machine (NP).
• Make sure that the ambient conditions comply with the Technical Data [►36].
• Make sure that the environmental conditions comply with the protection class of the
motor and the electrical instruments.
• Make sure that the installation space or location is vented such that sufficient cooling
of the machine is provided.
• Make sure that the oil sight glass (OSG) remains easily visible.
• Make sure that enough space remains for maintenance work.
• Make sure that the machine is placed or mounted horizontally, a maximum of 1° in
any direction is acceptable.
• Check the oil level, see Oil Level Inspection [►27].
• Check the cooling liquid level, see Cooling Liquid Level Inspection [►27].
• Make sure that the cooling water complies with the requirements, see Cooling Water
Connection [►14].
If the machine is installed at an altitude greater than 1000 meters above sea level:
• Contact your Busch representative, the motor should be derated or the ambient
temperature limited.
If additional electrical components not included in scope of delivery should be added:
• Make sure that they have a better or equal ATEX classification than that of the
machine, see the ATEX marking on the nameplate (NP).
• Make sure that the installation space or location is ventilated enough in orderto pre-
vent the formation of an explosive area.

Installation | 5
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5.2 Connecting Lines / Pipes
• Remove all protective covers before installation.
• Make sure that the connections are gas tight.
• Make sure that the connection lines cause no stress on the machine‘s connection; if
necessary use flexible joints.
• Make sure that the line size of the connection lines over the entire length is at least as
large as the connections of the machine.
In case of very long connection lines it is advisable to use larger line sizes in order to
avoid a loss of efficiency. Seek advice from your Busch representative.
WARNING
The connection lines can build up an electrostatic charge.
Risk of severe injury!
Risk of explosion!
• The connection lines must be made out of conductive material or provisions must be
made against creating an electrostatic charge.
5.2.1 Suction Connection
WARNING
Unprotected suction connection.
Risk of severe injury!
• Do not put hand or fingers in the suction connection.
NOTICE
Ingress of foreign objects or liquids.
Risk of damage to the machine!
If the inlet gas contains dust or other foreign solid particles:
• Install a suitable filter (5micron or less) upstream from the machine.
Connection size(s):
– DN100 ISO-K, DIN 28404 or DN100 ISO-F, DIN 28404
If the machine is used as part of a vacuum system:
• Busch recommends the installation of an isolation valve in order to prevent the
machine from turning backwards.
5.2.2 Discharge Connection
Connection size(s):
At the machine discharge connection:
– DN100 ISO-K, DIN 28404 or DN100 ISO-F, DIN 28404
At the silencer (SI) discharge connection (two optional versions available):
– DN80 PN16 + ANSI/ASME B16.5-3” class 150 lbs
– R3

5 | Installation
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• Make sure that the discharged gas will flow without obstruction. Do not shut off or
throttle the discharge line or use it as a pressurised air source.
• Make sure that the counter pressure (also termed back pressure) at the discharge con-
nection (OUT) does not exceed the maximum allowable discharge pressure, see Tech-
nical Data [►36].
5.2.3 Cooling Water Connection
CWI CWO
PHE
CWI Cooling water inlet CWO Cooling water outlet
PHE Plate heat exchanger
• Connect the cooling water connections (CWI / CWO) to the water supply.
Connection size:
– G1/2, ISO 228-1 (CWI / CWO)
• Make sure that the cooling water complies with the following requirements:
Supply capacity l/min 12
Water pressure bar 1 ... 6
Supply temperature °C +5 ... +30
Required pressure differential across supply
and return
bar ≥ 1
• To reduce the maintenance effort and ensure a long product lifetime we recommend
the following cooling water quality:
Hardness mg/l (ppm) < 90
Properties Clean & clear
PH value 7 … 8
Particle size µm < 200
Chloride mg/l < 100
Electrical conductivity µS/cm ≤ 100
Free chloride mg/l < 0.3
Materials in contact with the cooling water Stainless steel
NOTE
Water hardness unit conversion.
1 mg/l (ppm) = 0.056 °dh (german degree) = 0.07 °e (english degree) = 0.1 °fH (french
degree)

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5.2.4 Barrier Gas System Connection
With nitrogen panel
PRV MV
BGC MAN FME, FS NIP
BGC Barrier gas connection FME Flow meter
FS Flow switch MAN Manometer
MV Solenoid valve NIP Nitrogen panel
PRV Pressure regulating valve
• Connect the barrier gas connection (BGC) to the gas supply.
Connection size:
– G1/4, ISO 228-1
• Electrically connect the solenoid valve (MV), see Wiring Diagram Solenoid Valve.
• Electrically connect the flow switch (FS) of the flow meter, see Wiring Diagram Flow
Switch [►22].
• Make sure that the gas complies with the following requirements:
Gas type Dry nitrogen or air
Gas temperature °C 0 ... 60
Maximum gas pressure bar 13
Recommended pressure setting at the
pressure regulating valve (PRV)
bar 3
Filtration µm 5
Recommended flow rate SLM* 3,5 ... 5,5
Air quality (only for air) Acc. to ISO
8573-1
Class 5.4.4.
* standard litre per minute

5 | Installation
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5.3 Earth Connection
In order to prevent the machine from creating an electrostatic charge:
• Connect the earth connection in the motor terminal box (MTB). See Electrical Con-
nection [►18]
5.4 Filling Oil
NOTICE
Use of an inappropriate oil.
Risk of premature failure!
Loss of efficiency!
• Only use an oil type which has previously been approved and recommended by
Busch.
For oil type and oil capacity see Technical Data [►36] and Oil [►36].
1
2
Busch Oil
3
MAX
MIN
4
Check oil level
Oil filling at the motor side

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4
2
Busch Oil
3
MAX
MIN
1
Check oil level
Oil filling at the suction side
When the oil filling is achieved:
• Write down the oil change date on the sticker.
Last oil change
__ / __ / ____
Oil type see nameplate
Change interval see
instruction manual
If there is no sticker (part no. 0565 568 959) on the machine:
• Order it from your Busch representative.

5 | Installation
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5.5 Filling Cooling Liquid
For cooling liquid type and cooling liquid capacity see Technical Data [►36] and
Cooling Liquid [►36].
4
1
2
Cooling
liquid
Zitrec M-25
3
Fill up to the top of the vent orifice
5.6 Electrical Connection
DANGER
Live wires.
Risk of electrical shock.
• Electrical installation work must only be executed by qualified personnel.
• Make sure that the power supply for the motor is compatible with the data on the
nameplate of the motor.
• The electrical installation must comply with applicable national and international
standards.
• Provide a lockable disconnect switch on the power line so that the machine is com-
pletely secured during maintenance tasks.
• Provide an overload protection according to EN 60204-1 for the motor.
• Make sure that the motor of the machine will not be affected by electric or electro-
magnetic disturbance from the mains; if necessary seek advice from Busch.
• Connect the protective earth conductor.
• Electrically connect the motor.

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NOTICE
The admissible motor nominal speed exceeds the recommendation.
Risk of damage to the machine!
• Check the admissible motor nominal speed (nmax) on the nameplate of the machine
(NP).
• Make sure to comply with it.
• Consult the Technical Data [►36] to get more information.
NOTICE
The motor frequency is below 20 Hz.
Risk of damage to the machine!
• The motor nominal speed must always be higher than 1200 min-1 (20 Hz).
NOTICE
Incorrect connection.
Risk of damage to the motor!
• The wiring diagrams given below are typical. Check the inside of the terminal box for
motor connection instructions/diagrams.
5.6.1 Wiring Diagram Three-Phase Motor (Pump Drive)
Motor connectors: Connection of motor temperature
switches (recommended):
T9
T8
T6
T7
T5
T3
T1
T2
T4
P1
P2
P3
P4
P1 P2
MTS1 MTS2 MTS3
Control voltage: ≤ 250 V
Max current: 1.6 A
MTS = Motor temperature switch (in mo-
tor coil)
Double star connection (low voltage):
T1
T6T3
T5T8
T4
T2
T7
T9
Star connection (high voltage):
T1
T6T3
T5T8
T4
T2
T7
T9

5 | Installation
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NOTICE
Incorrect direction of rotation.
Risk of damage to the machine!
• Operation in the wrong direction of rotation can destroy the machine in a short time!
Prior to start-up, ensure that the machine is operated in the right direction.
The intended rotation direction of the motor is defined by the illustration below:
IN
• Jog the motor briefly.
• With a phase rotation tester, check if the wiring corresponds to the correct direction of
rotation.
If the rotation of the motor must be changed:
• Switch any two of the motor phase wires.
5.7 Electrical Connection of the Monitoring Devices
NOTE
In order to prevent potential nuisance alarms, Busch allows that the control system is
configured with a time delay of 2 seconds.
NOTE
The accessories below are considered as standard.
If other specific components should be used, refer to the instruction manual of the ac-
cessory in question.
WARNING
If the monitoring sensors are not used.
Risk of explosion!
• Always use the mandatory monitoring sensors.