BUSCH COBRA NX 0450 A User manual

Instruction Manual
COBRA
Dry Screw Vacuum Pumps
NX 0450 A, NX 0650 A
0870565358/B0004_en / Original instructions / Modifications reserved 13/10/2017
Ateliers Busch S.A.
Zone industrielle, 2906 Chevenez
Switzerland

Table of Contents
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Table of Contents
1 Safety........................................................................................................................... 3
2 Product Description ..................................................................................................... 4
2.1 Operating Principle...............................................................................................5
2.2 Application ........................................................................................................... 5
2.3 Standard Features.................................................................................................6
2.3.1 Water Cooling ..........................................................................................6
2.3.2 Temperature Switch...................................................................................6
2.3.3 Sealing Systems .........................................................................................6
2.4 Optional Accessories............................................................................................. 6
2.4.1 Gas Ballast Valve........................................................................................6
2.4.2 Silencer......................................................................................................6
2.4.3 Barrier Gas System.....................................................................................6
3 Transport ..................................................................................................................... 6
4 Storage......................................................................................................................... 7
5 Installation................................................................................................................... 7
5.1 Installation Conditions .......................................................................................... 7
5.2 Connecting Lines / Pipes ......................................................................................8
5.2.1 Suction Connection....................................................................................8
5.2.2 Discharge Connection................................................................................9
5.2.3 Cooling Water Connection ........................................................................9
5.2.4 Barrier Gas System Connection (Optional) .................................................10
5.3 Filling Oil..............................................................................................................11
5.4 Electrical Connection ............................................................................................12
5.4.1 Wiring Diagram Three-Phase Motor (Pump Drive).....................................13
5.5 Electrical Connection of the Monitoring Devices ................................................... 14
5.5.1 Wiring Diagram Temperature Switch .........................................................14
6 Commissioning............................................................................................................ 15
7 Maintenance................................................................................................................ 16
7.1 Maintenance Schedule.......................................................................................... 16
7.2 Oil Level Inspection .............................................................................................. 17
7.3 Cleaning the Inlet Screen ......................................................................................17
7.4 Cleaning the Gas Ballast Filter (Optional).............................................................. 18
7.5 Oil Change...........................................................................................................18
8 Overhaul...................................................................................................................... 21
9 Decommissioning ........................................................................................................ 21
9.1 Dismantling and Disposal...................................................................................... 22
10 Spare Parts................................................................................................................... 22
11 Troubleshooting........................................................................................................... 22
12 Technical Data ............................................................................................................. 24
13 Oil ............................................................................................................................... 24
14 EU Declaration of Conformity ...................................................................................... 25

Safety | 1
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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.

2 | Product Description
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2 Product Description
EB IN, IS
OUT
PMR MP
BGR MTBCWD
SI
OSG
GBOFPTSCWO
BGCBGMODP
BGF
OFP
OSGCWDODP
CWI
NP MP
OUTCD
BGC Barrier gas connection BGF Barrier gas flow meter
BGM Barrier gas manometer BGR Barrier gas pressure regulator
CD Condensate drain CWD Cooling water drain plug
CWI Cooling water inlet CWO Cooling water outlet
EB Eye bolt GB Gas ballast valve
IN Suction connection IS Inlet screen
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 TS Temperature switch

Product Description | 2
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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 pumping medium is trapped
between the individual screw coils, compressed and transported to the gas discharge.
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 process 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.
The machine is suitable for continuous operation.
Permitted environmental conditions see Technical Data [►24].
NOTICE
Chemical compatibility of the process gases with the machine component materials.
Risk of corrosion inside the compression chamber which can reduce performance and
its lifetime!
• Check if the process gases are compatible with those following materials:
- Cast iron
- Steel
- Aluminium
- Fluoroelastomer (FKM/FPM)
• In doubt, please contact your Busch representative.

3 | Transport
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2.3 Standard Features
2.3.1 Water Cooling
The machine is cooled by a cooling water circuit in the cylinder cover and cylinder.
2.3.2 Temperature Switch
The temperature switch monitors the cooling water temperature of the machine.
The temperature switch has two switch points:
Switch point 1 (T1) Early warning
Switch point 2 (T2) Trip, the machine must be stopped
2.3.3 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.
Depending on the application, the sealing systems efficiency can be improved with a
barrier gas system, see Barrier Gas System [►6].
2.4 Optional Accessories
2.4.1 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 [►24].
2.4.2 Silencer
A silencer at the discharge connection (OUT) can be provided to reduce the exhaust gas
noise.
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.
3 Transport
WARNING
Suspended load.
Risk of severe injury!
• Do not walk, stand or work under suspended loads.

Storage | 4
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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.
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.
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
5.1 Installation Conditions
• Make sure that the environment of the machine is not potentially explosive.
• Make sure that the ambient conditions comply with the Technical Data [►24].
• Make sure that the environmental conditions comply with the protection class of the
motor.

5 | Installation
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• 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.
• Check the oil level, see Oil Level Inspection [►17].
• Make sure that the cooling water complies with the requirements, see Cooling Water
Connection [►9].
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
• 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.
5.2.1 Suction Connection
WARNING
Unprotected suction connection.
Risk of severe injury!
• Do not put hand or fingers in the suction connection.
NOTICE
Intruding 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:
– G3
– DN100 ISO-K, 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.

Installation | 5
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5.2.2 Discharge Connection
COBRA
Discharge variants (without silencer)
Connection size:
At the machine discharge connection:
– G2 for NX 0450 A, horizontal (orientable 180°)
– G3 for NX 0650 A, horizontal (orientable 180°)
– DIN63 ISO-K, DIN 28404 for NX 0450 A, vertical (without discharge elbow)
– DN100 ISO-K, DIN 28404 for NX 0650 A, vertical (without discharge elbow)
At the silencer (SI) discharge connection (Optional):
– G2 for NX 0450 A, G3 for NX 0650 A, horizontal
• 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 at the discharge connection (OUT) does not ex-
ceed the admissible pressure, see Technical Data [►24].
5.2.3 Cooling Water Connection
CWI CWO
CWI Cooling water inlet CWO Cooling water outlet
Connection size:
– G1/2, ISO 228-1 (CWI / CWO)

5 | Installation
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• Make sure that the cooling water complies with the following requirements:
Supply capacity l/min 4...10forNX0450A
6...14forNX0650A
Water pressure bar 1 ... 6
Supply temperature °C +10 ... +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, aluminium and cast iron
NOTE
Water hardness unit conversion.
1 mg/l (ppm) = 0.056 °dh (german degree) = 0.07 °e (english degree) = 0.1 °fH (french
degree)
• Make sure that the water flow of the cooling water at the outlet (CWO) is monitored.
If it is not possible, Busch recommends calibrating the flow with one or two orifices
depending on the water pressure, see the following table:
Diameter of the orifice Differential water pressure
NX 0450 A NX 0650 A
No calibration n/a 1 … 2 bar
4 mm at the cooling water outlet 1 … 2 bar 2 … 3 bar
4 mm at the cooling water inlet and outlet 2 … 6 bar 3 … 6 bar
5.2.4 Barrier Gas System Connection (Optional)
PRV BGFBGCBGM
BGC Barrier gas connection FME Flow meter
MAN Manometer PRV Pressure regulating valve

Installation | 5
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Connection size:
– G1/4, ISO 228-1
• 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* 10 ... 15forNX0450A
15 ... 20forNX0650A
Air quality (only for air) Acc. to ISO
8573-1
Class 5.4.4.
* standard litre per minute
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 [►24] and Oil [►24].
1
2
Busch Oil
MAX
MIN
3
4
Check oil level
Oil filling at the motor side

5 | Installation
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1
2
Busch Oil
MAX
MIN
3
4
Check oil level
Oil filling at the inlet 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 on the pump:
• Order it from your Busch representative.
5.4 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.
• Provide 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.

Installation | 5
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• 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 [►24] 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.
5.4.1 Wiring Diagram Three-Phase Motor (Pump Drive)
Delta connection (low voltage): Star connection (high voltage):
Double star connection, multi-voltage
motor with 12 pins (low voltage):
4
4
4
Star connection, multi-voltage motor
with 12 pins (high voltage):
4
4
4

5 | Installation
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Delta connection, multi-voltage motor
with 12 pins (middle voltage):
4
4
4
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.
• Watch the fan wheel of the motor and determine the direction of rotation just before
the fan wheel stops.
If the rotation of the motor must be changed:
• Switch any two of the motor phase wires.
5.5 Electrical Connection of the Monitoring Devices
NOTE
In order to prevent potential nuisance alarms, Busch recommends that the control system
is configured with a time delay of at least 10 seconds.
5.5.1 Wiring Diagram Temperature Switch
Part no.: 0651563762
Connector: M12x1, 4-pin
U = ≤ 250 V AC/DC (50/60 Hz) ; I = ≤ 1 A
Switch point:
Twarning = T1 ► pin 1 + 2
Ttrip = T2 ► pin 3 + 4
1 2
43
2
1
T1
4
3
T2
1 = Brown ; 2 = White ;
3 = Blue ; 4 = Black

Commissioning | 6
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6 Commissioning
NOTICE
The machine is shipped without oil.
Operation without oil will ruin the machine in short time!
• Prior to commissioning, the machine must be filled with oil, see Filling Oil [►11].
NOTICE
Lubricating a dry running machine (process chamber).
Risk of damage to the machine!
• Do not lubricate the process chamber of the machine with oil or grease.
CAUTION
During operation the surface of the machine may reach temperatures of more than
70°C.
Risk of burns!
• Avoid contact with the machine during and directly after operation.
CAUTION
Noise of running machine.
Risk of damage to hearing!
If persons are present in the vicinity of a non noise insulated machine over extended
periods:
• Make sure that ear protection is being used.
• Make sure that the installation conditions (see Installation Conditions [►7]) are com-
plied with.
• Open the water supply.
If the machine is equipped with a barrier gas system:
• Open the barrier gas supply.
• Adjust the barrier gas pressure.
• Switch on the machine.
• Make sure that the maximum permissible number of starts does not exceed 6 starts
per hour.
• After few minutes of operation, perform an Oil Level Inspection [►17].
As soon as the machine is operated under normal operating conditions:
• Measure the motor current and record it as reference for future maintenance and
troubleshooting work.

7 | Maintenance
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7 Maintenance
WARNING
Machines contaminated with hazardous material.
Risk of poisoning!
Risk of infection!
If the machine is contaminated with hazardous material:
• Wear appropriate personal protective equipment.
CAUTION
Hot surface.
Risk of burns!
• Prior to any action requiring touching the machine, let the machine cool down first.
• Shut down the machine and lock against inadvertent start up.
• Turn off the water supply.
If the machine is equipped with a barrier gas system:
• Close the barrier gas supply.
• Vent the connected lines to atmospheric pressure.
If necessary:
• Drain the cooling water from the two cooling water drain plugs (CWD).
• Disconnect all connections.
7.1 Maintenance Schedule
The maintenance intervals depend very much on the individual operating conditions. The
intervals given below are desired to be considered as starting values which should be
shortened or extended as appropriate. Particularly heavy duty operation, such as high
dust loads in the environment or in the process gas, other contamination or ingress of
process material, can make it necessary to shorten the maintenance intervals significant-
ly.
Interval Maintenance work
Monthly • Check the oil level, see Oil Level Inspection [►17].
• Check the machine for oil leaks - in case of leaks have
the machine repaired (contact Busch).
Yearly • Carry out a visual inspection and clean the machine
from dust and dirt.
• Check the electrical connections and the monitoring
devices.
• Clean the inlet screen, see Cleaning the Inlet Screen
[►17].
Yearly
In case of those accessories
being installed.
• Check the filter of the gas ballast valve (GB) and
clean it if necessary, see Cleaning the Gas Ballast Fil-
ter (Optional) [►18].
• Check the silence (SI) and clean it if necessary.

Maintenance | 7
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Every 8500 hours, at the latest
after 1 year
• Change the oil of the gear and bearing housings
(both sides), see Oil Change [►18].
• Clean the magnetic plugs (MP).
Every 25000 hours, at the
latest after 4 years
• Have a major overhaul on the machine (contact
Busch).
7.2 Oil Level Inspection
• Shut down the machine.
• When the machine is stopped, wait 1 minute before checking the oil level.
MAX
MIN
MAX
MIN
MAX
MIN
• Fill up if necessary, see Oil Filling [►11].
7.3 Cleaning the Inlet Screen
1
8x
2
8x
3
Compressed air
hex key

7 | Maintenance
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7.4 Cleaning the Gas Ballast Filter (Optional)
1
2
3
Compressed air
36 mm wrench
7.5 Oil Change
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.

Maintenance | 7
0870565358_NX0450-0650A_B0004_IM_en 19 / 28
1
2
34
Cleaning cloth
Oil draining at the motor side
Drain pan
Magnetic plug
12
3
4
Cleaning cloth
Oil draining at the suction side
Drain pan
Magnetic plug

7 | Maintenance
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For oil type and oil capacity see Technical Data [►24] and Oil [►24].
1
2
Busch Oil
MAX
MIN
3
4
Check oil level
Oil filling at the motor side
1
2
Busch Oil
MAX
MIN
3
4
Check oil level
Oil filling at the inlet side
When the oil filling is achieved:
• Write down the oil change date on the sticker.