BUSCH COBRA NC 1000 B User manual

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COBRA
Dry Screw Vacuum Pumps
NC 1000 B Water-Cooled Version (WCV)
Instruction Manual
0870551589 | A0004_en-US | Original instructions 11/22/2022

Table of Contents
2 | 40 Instruction Manual COBRA NC 1000 B WCV_EN_en
Table of Contents
1 Safety..................................................................................................................................................................... 4
2 Product Description............................................................................................................................................. 5
2.1 Operating Principle ............................................................................................................................................. 6
2.2 Intended Use ....................................................................................................................................................... 6
2.3 Start Controls....................................................................................................................................................... 7
2.4 Standard Features............................................................................................................................................... 7
2.4.1 Water Cooling........................................................................................................................................ 7
2.4.2 Resistance Thermometer..................................................................................................................... 7
2.4.3 Level Switch ........................................................................................................................................... 7
2.4.4 Thermometer ........................................................................................................................................ 7
2.4.5 Sealing Systems..................................................................................................................................... 7
2.5 Optional Accessories........................................................................................................................................... 7
2.5.1 Gas Ballast Valve ................................................................................................................................... 7
2.5.2 Silencer................................................................................................................................................... 7
2.5.3 Barrier Gas System ............................................................................................................................... 7
2.5.4 Mechanical Seals................................................................................................................................... 8
3 Transport .............................................................................................................................................................. 9
4 Storage .................................................................................................................................................................. 10
5 Installation ........................................................................................................................................................... 11
5.1 Installation Conditions........................................................................................................................................ 11
5.2 Connecting Lines / Pipes .................................................................................................................................... 11
5.2.1 Suction Connection............................................................................................................................... 12
5.2.2 Discharge Connection .......................................................................................................................... 12
5.2.3 Cooling Water Connection................................................................................................................... 13
5.2.4 Barrier Gas System Connection (Optional) ........................................................................................ 14
5.3 Filling Oil............................................................................................................................................................... 15
5.4 Filling Cooling Liquid........................................................................................................................................... 16
5.5 Fitting the Coupling ............................................................................................................................................ 17
6 Electrical Connection........................................................................................................................................... 18
6.1 Machine delivered without Control Box or Variable Speed Drive (VSD)....................................................... 18
6.2 Wiring Diagram Three-Phase Motor (Pump Drive)......................................................................................... 19
6.3 Electrical Connection of the Monitoring Devices ............................................................................................ 20
6.3.1 Wiring Diagram Resistance Thermometer ........................................................................................ 20
6.3.2 Wiring Diagram Level Switch............................................................................................................... 20
7 Commissioning..................................................................................................................................................... 21
7.1 Conveying Condensable Vapors........................................................................................................................ 22
8 Maintenance......................................................................................................................................................... 23
8.1 Maintenance Schedule ....................................................................................................................................... 24
8.2 Oil Level Inspection............................................................................................................................................. 24
8.3 Cooling Liquid Level Inspection......................................................................................................................... 25
8.4 Replacing the Gas Ballast Filter (Optional)....................................................................................................... 25
8.5 Oil Change............................................................................................................................................................ 26
8.6 Cooling Liquid Change ....................................................................................................................................... 29
9 Overhaul................................................................................................................................................................ 30
10 Decommissioning................................................................................................................................................. 31
10.1 Dismantling and Disposal .................................................................................................................................. 31
11 Spare Parts............................................................................................................................................................ 32

Table of Contents
Instruction Manual COBRA NC 1000 B WCV_EN_en 3 | 40
12 Troubleshooting................................................................................................................................................... 33
13 Technical Data...................................................................................................................................................... 35
14 Cooling Liquid....................................................................................................................................................... 36
15 Oil........................................................................................................................................................................... 37
16 EU Declaration of Conformity............................................................................................................................. 38
17 UK Declaration of Conformity ............................................................................................................................ 39

1 | Safety
4 | 40 Instruction Manual COBRA NC 1000 B WCV_EN_en
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 methods. Never-
theless, residual risks may remain, as described in the following chapters and in accordance with the
chapter Intended Use [➔6]. This instruction manual highlights potential hazards where appropri-
ate. 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 trou-
ble-free operation.

Product Description | 2
Instruction Manual COBRA NC 1000 B WCV_EN_en 5 | 40
2 Product Description
EB
IN
OUT
PMR
CLP
SI
OFP
SV
MP
OUT
CLFGB CLG
CDCLD
OSG
OSG
MP
MTB
NP
OFP
TSAODP
LS
TM
CWOPHECWI
ODPCLD
Description
IN Suction connection (Inlet) OUT Discharge connection (Outlet)
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 LS Level switch
MP Magnetic plug MTB Motor terminal box
NP Nameplate ODP Oil drain plug
OFP Oil fill plug OSG Oil sight glass
PHE Plate heat exchanger PMR Plug for manual rotation of rotors
SI Silencer SV Safety valve
TM Thermometer TSA Resistance thermometer

2 | Product Description
6 | 40 Instruction Manual COBRA NC 1000 B WCV_EN_en
NOTE
Technical term.
In this instruction manual, we consider that the term ‘machine’ refers to the ‘vacuum pump’.
NOTE
Illustrations
In this instruction manual, the illustrations may differ from the machine appearance.
2.1 Operating Principle
The machine works on the one-stage, twin-screw pump principle.
Two screw rotors rotate inside the cylinder. The pumped medium is trapped between the cylinder
and screw chambers, compressed, and transported to the gas outlet. During the compression pro-
cess, the two screw rotors do not come into contact with each other or with the cylinder. There is no
need for a lubrication or an operating fluid in the compression chamber.
2.2 Intended Use
WARNING
In case of foreseeable misuse outside the intended use of the machine.
Risk of injuries!
Risk of damages to the machine!
Risk of damages to the environment!
●Make sure to follow all instructions described in this manual.
The machine is intended for the suction of air and other dry, non-aggressive, non-toxic and non-ex-
plosive 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.
The machine is suitable for continuous operation.
Permitted environmental conditions, see Technical Data.

Product Description | 2
Instruction Manual COBRA NC 1000 B WCV_EN_en 7 | 40
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 equipped with a soft-starter or a variable speed drive (not included in the scope
of supply).
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 Resistance Thermometer
The resistance thermometer monitors the cooling liquid temperature of the machine.
A trip signal must be set. The machine must be stopped when the cooling liquid temperature reach-
es 70 °C.
2.4.3 Level Switch
The level switch monitors the cooling liquid level in the cylinder.
The machine must be stopped when the cooling liquid level is too low.
2.4.4 Thermometer
The thermometer allows a visual display of the cooling liquid temperature.
2.4.5 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 [➔8].
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 sys-
tem, see Barrier Gas System [➔7].
2.5 Optional Accessories
2.5.1 Gas Ballast Valve
The gas ballast valve mixes the process gas with a limited quantity of ambient air to counteract the
condensation of vapor inside the machine.
The gas ballast valve has an influence on the ultimate pressure of the machine, see Technical Data.
A ball valve enables to open or close the gas ballast flow.
2.5.2 Silencer
A silencer at the discharge connection (OUT) can be provided to reduce the exhaust gas noise.
2.5.3 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 | Product Description
8 | 40 Instruction Manual COBRA NC 1000 B WCV_EN_en
2.5.4 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.

Transport | 3
Instruction Manual COBRA NC 1000 B WCV_EN_en 9 | 40
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 ingress into
the cylinder.
●Drain the oil prior to every transport or always horizontally transport the machine.
●To find out the weight of the machine, refer to the chapter 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
10 | 40 Instruction Manual COBRA NC 1000 B WCV_EN_en
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.
NOTICE
Long storage time.
Risk of damage to the machine!
●If the machine is equipped with oil lubricated mechanical seals, we recommend to completely fill
the oil chamber before a long storage, see “Oil filling” in chapter Oil Change [➔26]. This protects
the mechanical seals during a long storage. Use the standard pump oil, see chapter Oil [➔37].
●Before restarting the machine, drain the oil to the normal oil level, see “Oil draining” in chapter Oil
Change [➔26].

Installation | 5
Instruction Manual COBRA NC 1000 B WCV_EN_en 11 | 40
5 Installation
5.1 Installation Conditions
WARNING
If the machine is installed in a potentially explosive environment or if the machine is used to
draw toxic, inflammable or non-inert gases:
Risk of injuries!
Risk of death!
●Ensure that the machine complies with all local, national rules and safety regulations.
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.
●Make sure that the environmental conditions comply with the protection class of the motor and
the electrical elements.
●Make sure that the installation space or location is vented such that sufficient cooling of the ma-
chine is provided.
●Make sure that cooling air inlets and outlets of the motor fan are not covered or obstructed 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 deviation of 1° in any
direction is acceptable.
●Check the oil level, see Oil Level Inspection [➔24].
●Check the cooling liquid level, see Cooling Liquid Level Inspection [➔25].
●Make sure that the cooling water complies with the requirements, see Cooling Water Connection
[➔13].
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 covers before installation.
●Make sure that the connection lines cause no stress on the connection of the machine; if neces-
sary 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 long connection lines, it is advisable to use larger line sizes in order to avoid a loss of effi-
ciency. Seek advice from your Busch representative.

5 | Installation
12 | 40 Instruction Manual COBRA NC 1000 B WCV_EN_en
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):
– DN125 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
NOTICE
Discharge gas flow obstructed.
Risk of damage to the machine!
●Make sure that the discharged gas will flow without obstruction. Do not shut off or throttle the
discharge line or use it as a pressurized air source.
Connection size(s):
At the machine discharge connection:
– DN125 PN16, EN 1092-1
At the silencer (SI) discharge connection (two optional versions available):
– DN125 PN16, EN 1092-1
– DN100 ISO-K, DIN 28404
●Make sure that the counter pressure (also termed back pressure) at the discharge connection
(OUT) does not exceed the maximum allowable discharge pressure, see Technical Data.

Installation | 5
Instruction Manual COBRA NC 1000 B WCV_EN_en 13 | 40
5.2.3 Cooling Water Connection
CWI CWO PHE
Description
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 15
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 follow-
ing 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)

5 | Installation
14 | 40 Instruction Manual COBRA NC 1000 B WCV_EN_en
5.2.4 Barrier Gas System Connection (Optional)
Without nitrogen panel
PRV FRBGCMANFME
Description
BGC Barrier gas connection FME Flow meter
FR Flow regulator MAN Manometer
PRV Pressure regulating valve
●Connect the barrier gas connection (BGC) to the gas supply.
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 pres-
sure regulating valve (PRV)
bar(a) 3
Filtration µm 5
Recommended flow rate SLM (standard li-
ter per minute)
30
Air quality (only for air) Acc. to ISO
8573-1
Class 5.4.4.

Installation | 5
Instruction Manual COBRA NC 1000 B WCV_EN_en 15 | 40
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 and Oil [➔37].

5 | Installation
16 | 40 Instruction Manual COBRA NC 1000 B WCV_EN_en
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.
5.4 Filling Cooling Liquid
For cooling liquid type and cooling liquid capacity see Technical Data and Cooling Liquid [➔36].

Installation | 5
Instruction Manual COBRA NC 1000 B WCV_EN_en 17 | 40
5.5 Fitting the Coupling
NOTE
Radial screw.
For trouble-free operation, use thread locking glue to secure the radial screw.
1 2 3
4
Description
1 Coupling hub (machine side) 2 Coupling spider
3 Coupling hub (motor side) 4 Radial screw / max. admissible torque:
10Nm
Machine type Coupling size Value “E” (mm)
NC 1000 B ROTEX® 48 28
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 RO-
TEX® coupling.
English German French
Instruction Manual - English Instruction Manual - German Instruction Manual - French

6 | Electrical Connection
18 | 40 Instruction Manual COBRA NC 1000 B WCV_EN_en
6 Electrical Connection
DANGER
Live wires.
Risk of electrical shock.
●Electrical installation work must only be executed by qualified personnel.
CURRENT PROTECTION OF THE CUSTOMER INSTALLATION:
DANGER
Missing current protection.
Risk of electrical shock.
●Current protection according to EN 60204-1 must be insured by the customer on its installation.
●The electrical installation must comply with the applicable national and international standards.
NOTICE
Electromagnetic compatibility.
●Make sure that the motor of the machine will not be affected by electric or electromagnetic dis-
turbance from the mains, if necessary seek advice from Busch.
●Make sure that the EMC of the machine is compliant with the requirements of your supply net-
work system, if necessary provide further interference suppression (EMC of the machine, see EU
Declaration of Conformity [➔38] or UK Declaration of Conformity [➔39]).
6.1 Machine delivered without Control Box or Variable
Speed Drive (VSD)
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.
●If the machine is equipped with a power connector, install a residual current protective device to
protect persons in case of isolation default.
●Busch recommends installing a type B residual protective device suitable for the electrical in-
stallation.
●Provide a lockable disconnect switch or an emergency stop switch on the power line so that the
machine is completely secured in case of an emergency situation.
●Provide a lockable disconnect switch on the power line so that the machine is completely secured
during maintenance tasks.

Electrical Connection | 6
Instruction Manual COBRA NC 1000 B WCV_EN_en 19 | 40
●Provide an overload protection according to EN 60204-1 for the motor.
●Connect the protective earth conductor.
●Electrically connect the motor.
NOTICE
The motor frequency is below 30 Hz.
Risk of damage to the machine!
●The motor nominal speed must always be higher than 1800 min-1 (30 Hz).
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 to get more information.
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 con-
nection instructions/diagrams.
6.2 Wiring Diagram Three-Phase Motor (Pump Drive)
Delta connection (low voltage): Star connection (high voltage):
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.

6 | Electrical Connection
20 | 40 Instruction Manual COBRA NC 1000 B WCV_EN_en
The intended rotation direction of the motor is defined by the illustration below:
●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.
6.3 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 20 seconds.
6.3.1 Wiring Diagram Resistance Thermometer
Part no.: 0651 552 252
Connector: M12x1, 4-pin
U = 7.5 … 30 VDC
4 ... 20 mA ► -50 ... 150 °C
Trip signal: Ttrip: 70 °C
1 2
4 3
3
1
+
-
1 = Brown ; 3 = Blue
6.3.2 Wiring Diagram Level Switch
Part no.: 0652 569 236
Connector: M12x1, 4-pin
U = 10 … 30 VDC (DC-PNP)
Imax = 200 mA
Contact: Normally closed
1 2
4 3
(+)
1
3
4(-)
0.5 A
1 = Brown ; 3 = Blue ; 4 = Black
Switch point:
Ltrip ► pin 1 + 4 ► low level “stop the machine”