BUSCH COBRA Oxygen NC 0400 B User manual

Instruction Manual
COBRA
Dry Screw Vacuum Pumps
NC 0400 B (water-cooled version)
0870565283/A0005_en / Original instructions / Modifications reserved 10/04/2019
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 ...........................................................................................6
2.4.2 Temperature Switch...................................................................................7
2.4.3 Thermometer.............................................................................................7
2.4.4 Sealing Systems .........................................................................................7
2.5 Optional Accessories............................................................................................. 7
2.5.1 Inlet Filter ..................................................................................................7
2.5.2 Gas Ballast Valve........................................................................................7
2.5.3 Silencer......................................................................................................7
2.5.4 Barrier Gas System.....................................................................................7
2.5.5 Mechanical Seals........................................................................................7
2.5.6 Nitrogen Panel...........................................................................................8
2.5.7 Liquid Flushing Device ...............................................................................8
3 Transport ..................................................................................................................... 8
4 Storage......................................................................................................................... 9
5 Installation................................................................................................................... 10
5.1 Installation Conditions .......................................................................................... 10
5.2 Connecting Lines / Pipes ......................................................................................10
5.2.1 Suction Connection....................................................................................11
5.2.2 Discharge Connection................................................................................11
5.2.3 Cooling Water Connection ........................................................................12
5.2.4 Barrier Gas System Connection (Optional) .................................................13
5.2.5 Dilution Gas System Connection (Optional)...............................................14
5.2.6 Purge Gas System Connection (Optional) ..................................................15
5.3 Filling Oil..............................................................................................................16
5.4 Filling Cooling Liquid ............................................................................................ 18
5.5 Liquid Flushing Device Installation (Optional) ....................................................... 18
5.6 Fitting the Coupling..............................................................................................19
5.7 Electrical Connection ............................................................................................20
5.7.1 Wiring Diagram Three-Phase Motor (Pump Drive).....................................21
5.7.2 Wiring Diagram Solenoid Valve (Optional) ................................................22
5.8 Electrical Connection of the Monitoring Devices ................................................... 22
5.8.1 Wiring Diagram Temperature Switch .........................................................22
5.8.2 Wiring Diagram Flow Switch (Optional).....................................................22
5.8.3 Wiring Diagram Level Switch (Optional)....................................................22
6 Commissioning............................................................................................................ 23
6.1 Conveying Condensable Vapours ......................................................................... 24
6.2 Liquid Flushing Procedure.....................................................................................24
6.3 Gas Purging Procedure ......................................................................................... 25
7 Maintenance................................................................................................................ 25
7.1 Maintenance Schedule.......................................................................................... 26
7.2 Oil Level Inspection .............................................................................................. 27
7.3 Cooling Liquid Level Inspection ............................................................................27
7.4 Replacing the Gas Ballast Filter (Optional) ............................................................ 27

Table of Contents
0870565283_NC0400B_WCV_A0005_IM_en 3
7.5 Oil Change...........................................................................................................28
7.6 Cooling Liquid Change ......................................................................................... 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
EB
IN
OUT
PMR CLP
CWI
SI
OFP
SV
CWO
MP
OUT
CLFGB CLG
CD
TM CLD
PHE
OSG
TS
OSG
MP
MTB
NP
OFP
ODPODP
CD Condensate drain CLD Cooling liquid drain plug
CLF Cooling liquid fill plug CLG Cooling liquid sight glass
CLP Cooling liquid pump CWI Cooling water inlet
CWO Cooling water outlet EB Eye bolt
GB Gas ballast valve 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 PHE Plate heat exchanger
PMR Plug for manual rotation of rotors SI Silencer
SV Safety valve TM Thermometer
TS Temperature switch

2 | Product Description
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NOTE
Technical term.
In this instruction manual, we consider that the term ‘machine’ refers to the ‘vacuum
pump’.
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, non-toxic
and non-explosive gases.
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 intended for the placement in a non-potentially explosive environment.
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.
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.

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2.4.2 Temperature Switch
The temperature switch monitors the oil temperature of the machine.
The machine must be stopped when the temperature switch trips (85 °C).
2.4.3 Thermometer
The thermometer allows a visual display of the cooling liquid temperature.
2.4.4 Sealing Systems
The machine is equipped with labyrinth seals on the motor side and suction side.
Other sealing systems are optionally available, see Mechanical Seals [►7].
Sealing systems prevent the process gas going to the bearings chambers.
Depending on the application, the sealing systems efficiency can be improved with a
barrier gas system, see Barrier Gas System [►7].
2.5 Optional Accessories
2.5.1 Inlet Filter
The inlet filter protects the machine against dust and other solids in the process gas. The
inlet filter is available with a paper cartridge.
2.5.2 Gas Ballast Valve
The gas ballast valve mixes the process gas with a limited quantity of ambient air to
counteract the condensation of vapour inside the machine.
The gas ballast valve has an influence on the ultimate pressure of the machine, see Tech-
nical Data [►36].
A ball valve enables to open or close the gas ballast flow.
2.5.3 Silencer
A silencer at the discharge connection (OUT) can be provided to reduce the exhaust gas
noise.
2.5.4 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.
This device is available either with or without nitrogen panel.
2.5.5 Mechanical Seals
The sealing systems can be equipped with mechanical seals. The following variants are
possible:
– Oil lubricated single mechanical seals on the motor side and labyrinth seals on the
suction side.
– Oil lubricated single mechanical seals on the motor side and suction side.

3 | Transport
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2.5.6 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 dilution gas ballast prevents the formation of condensates or dilutes them, de-
pending on the application. The nitrogen is fed into the cylinder.
– 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.
2.5.7 Liquid Flushing Device
The liquid flushing device allows the machine to be flushed with the appropriate liquid
according to the process type. The system consists of a solenoid valve which enables to
open and close the flushing liquid circuit.
Furthermore, two level switches (LS1 and LS2) monitor the flushing liquid quantity.
Upper level switch (LS1 ► Lalarm) Early warning
Lower level switch (LS2 ► Ltrip) Trip, the flushing must be stopped
3 Transport
WARNING
Suspended load.
Risk of severe injury!
• Do not walk, stand or work under suspended loads.
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.

Storage | 4
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Machine weight:
see the technical data or the nameplate (NP)
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
previously shown.
• 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
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 is not potentially explosive.
• 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 cooling air inlets and outlets of the motor fan are not covered or ob-
structed and that the cooling air flow is not affected adversely in any other way.
• 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 [►12].
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.
5.2 Connecting Lines / Pipes
• Remove all protective caps before installation.
• 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.

Installation | 5
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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:
– DN63 ISO-K, DIN 28404
– DN80 PN6, EN 1092-1
If a purge gas system or a liquid flushing device being installed:
– DN80 PN16, EN 1092-1
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:
At the machine discharge connection:
– DN63 ISO-K, DIN 28404
– DN80 PN6, EN 1092-1
At the silencer (SI) discharge connection (two optional versions available):
– DN80 PN16 + ANSI/ASME B16.5-3” class 150 lbs
– R3
• 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 | Installation
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5.2.3 Cooling Water Connection
CWICWO 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 4 ... 6
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)

Installation | 5
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5.2.4 Barrier Gas System Connection (Optional)
Without nitrogen panel
PRVFR BGCMANFME
BGC Barrier gas connection FME Flow meter
FR Flow regulator MAN Manometer
PRV Pressure regulating valve
With nitrogen panel
PRV MVBGC MANFME, 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
Version with nitrogen panel:
• Electrically connect the solenoid valve (MV), see Wiring Diagram Solenoid Valve
[►22].
• 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:

5 | Installation
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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* 2 ... 3
Air quality (only for air) Acc. to ISO
8573-1
Class 5.4.4.
* standard litre per minute
5.2.5 Dilution Gas System Connection (Optional)
PRV MVDGC MANFME, FR NIP
DGC Dilution gas connection FME Flow meter
FR Flow regulator MAN Manometer
MV Solenoid valve NIP Nitrogen panel
PRV Pressure regulating valve
• Connect the dilution gas connection (DGC) to the gas supply.
Connection size:
– G1/4, ISO 228-1
• Electrically connect the solenoid valve (MV), see Wiring Diagram Solenoid Valve
[►22].
• Make sure that the gas complies with the following requirements:
Gas type Dry nitrogen
Gas temperature °C 0 ... 60
Maximum gas pressure bar 13
Recommended pressure setting at the
pressure regulating valve (PRV)
bar 0.5
Filtration µm 5
Recommended flow rate SLM* 20
* standard litre per minute

Installation | 5
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5.2.6 Purge Gas System Connection (Optional)
MAN MVPGC PRVFME, FR INF
NIP
PGC Purge gas connection FME Flow meter
FR Flow regulator INF Inlet flange
MAN Manometer MV Solenoid valve
NIP Nitrogen panel PRV Pressure regulating valve
• Connect the purge gas connection to the gas supply.
Connection size:
– G1/4, ISO 228-1
• Electrically connect the solenoid valve (MV), see Wiring Diagram Solenoid Valve
[►22].
• Make sure that the gas complies with the following requirements:
Gas type Dry nitrogen
Gas temperature °C 0 ... 60
Maximum gas pressure bar 13
Recommended pressure setting at the
pressure regulating valve (PRV)
bar 2.5
Filtration µm 5
Recommended flow rate SLM* ≥ 75
* standard litre per minute

5 | Installation
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5.3 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
3 mm
4
Check oil level
Oil filling at the motor side

Installation | 5
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1
2
Busch Oil
3
MAX
MIN
3 mm
4
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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5.4 Filling Cooling Liquid
For cooling liquid type and cooling liquid capacity see Technical Data [►36] and
Cooling Liquid [►36].
1
2
Cooling
liquid
Zitrec M-25
3
MAX
MIN
4
Check cooling liquid level
5.5 Liquid Flushing Device Installation (Optional)
LS1 FRLIFLV INFMVFLF LS2
FLF Flushing liquid fill plug FLV Flushing liquid vessel
FR Flow regulator INF Inlet flange
LI Level indicator LS Level switch
MV Solenoid valve

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• Electrically connect the solenoid valve (MV), see Wiring Diagram Solenoid Valve
[►22].
• Electrically connect the two level switches (LS), see Wiring Diagram Level Switch
[►22].
• Fill the flushing liquid vessel (FLV) with a process compatible flushing liquid.
5.6 Fitting the Coupling
E
Coupling hub (machine side) Coupling hub (motor side)Coupling spider
Radial screw
Max. admissible
torque: 10 Nm
Machine type Coupling size Value “E” (mm)
NC 0400 B ROTEX® 38 24
ROTEX® 42 26
In case of a machine delivery without motor:
• Fit the second coupling hub on the motor shaft (separately delivered).
• Axially adjust the hub in such a way until value "E" is reached.
• When the coupling adjustment is done, lock the coupling hub by tightening the
radial screw.
• Mount the motor on the machine by including the coupling spider.
For further coupling information, go to www.ktr.com and download the instruction
manual of the ROTEX® coupling.

5 | Installation
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5.7 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.
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.