BUSCH COBRA NC 0200 B User manual

Installation and
Maintenance Instructions
Screw Vacuum Pumps
COBRA NC 0200 ... 0300 B
VR - Vapour Recovery
Ateliers Busch S.A.
Zone industrielle
2906 Chevenez
Switzerland
0870558783/ 181017 / Original instructions / Modifications reserved

Table of Contents
Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Product Description. . . . . . . . . . . . . . . . . . . . . . . . . 4
Use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Principle of operation. . . . . . . . . . . . . . . . . . . . . . . 4
Principle schema . . . . . . . . . . . . . . . . . . . . . . . . 5
Cooling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Sealing systems. . . . . . . . . . . . . . . . . . . . . . . . . . 5
On/ Off switch . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Intended use . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Safety information . . . . . . . . . . . . . . . . . . . . . . . . 5
Safety stickers . . . . . . . . . . . . . . . . . . . . . . . . . 6
Noise emission . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Safety area . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Stopping procedure for maintenance. . . . . . . . . . . . . . 6
Start-up procedure after maintenance . . . . . . . . . . . . . 6
Transport . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Transportation of packaged pump . . . . . . . . . . . . . . . . 6
Transport in unpacked state . . . . . . . . . . . . . . . . . . . 6
Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Short-term Storage . . . . . . . . . . . . . . . . . . . . . . . . 7
Removal from storage . . . . . . . . . . . . . . . . . . . . . . 7
Conservation . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Starting-up of the vacuum pump after storage. . . . . . . . . 7
Installation and Commissioning . . . . . . . . . . . . . . . . . . 7
Installation prerequisites . . . . . . . . . . . . . . . . . . . . . 7
Local installation . . . . . . . . . . . . . . . . . . . . . . . . 7
Suction Connection . . . . . . . . . . . . . . . . . . . . . . 8
Discharge connection . . . . . . . . . . . . . . . . . . . . . 8
External cooling liquid connections. . . . . . . . . . . . . . . 8
Fitting the drive motor . . . . . . . . . . . . . . . . . . . . . 8
Fitting the coupling . . . . . . . . . . . . . . . . . . . . . 9
Control intervals. . . . . . . . . . . . . . . . . . . . . . . 9
Axial displacement. . . . . . . . . . . . . . . . . . . . . . 9
Electrical connection/ Checks . . . . . . . . . . . . . . . . . 9
Resistance thermometer PT 100 (TSA) . . . . . . . . . . . . 10
Technical data . . . . . . . . . . . . . . . . . . . . . . . 10
Electrical wiring . . . . . . . . . . . . . . . . . . . . . . 10
Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Fitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Electrical connection . . . . . . . . . . . . . . . . . . . . . 10
Connecting up of lines/ pipes. . . . . . . . . . . . . . . . . 11
Filling up with oil . . . . . . . . . . . . . . . . . . . . . . . 11
Filling in cooling liquid . . . . . . . . . . . . . . . . . . . . 11
Connection of the external cooling liquid supply . . . . . . . 11
Saving the operating parameters . . . . . . . . . . . . . . . 12
Recommendations on operation. . . . . . . . . . . . . . . . . 12
Application . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Switching the vacuum pump on/ off . . . . . . . . . . . . . 12
First start-up of the system. . . . . . . . . . . . . . . . . 12
Switching off the system . . . . . . . . . . . . . . . . . . 12
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Maintenance program. . . . . . . . . . . . . . . . . . . . . . 13
Monthly: . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Yearly: . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Every 5000 operating hours: . . . . . . . . . . . . . . . . . 13
Every 10’000 operating hours: . . . . . . . . . . . . . . . . 13
Every 16’000 operating hours, at the latest after 4 Years:. . . 14
Stopping procedure for maintenance . . . . . . . . . . . . . 14
Start-up after maintenance . . . . . . . . . . . . . . . . . . 14
Checking the oil. . . . . . . . . . . . . . . . . . . . . . . . . 14
Checking the oil level . . . . . . . . . . . . . . . . . . . . . 14
Topping up with oil. . . . . . . . . . . . . . . . . . . . . . 14
Life-span of the Oil . . . . . . . . . . . . . . . . . . . . . 14
Changing the oil . . . . . . . . . . . . . . . . . . . . . . . . 14
Draining used oil . . . . . . . . . . . . . . . . . . . . . . . 14
Filling in new oil . . . . . . . . . . . . . . . . . . . . . . . 15
Checking the cooling liquid . . . . . . . . . . . . . . . . . . . 15
Checking the level of the cooling liquid . . . . . . . . . . . . 15
Checking the cooling liquid temperature . . . . . . . . . . . 15
Topping up with cooling liquid . . . . . . . . . . . . . . . . 15
Changing the cooling liquid . . . . . . . . . . . . . . . . . . . 15
Draining the cooling liquid . . . . . . . . . . . . . . . . . . 15
Filling up with new cooling liquid . . . . . . . . . . . . . . . 15
Checking the external cooling liquid. . . . . . . . . . . . . . . 16
Checking the current consumption . . . . . . . . . . . . . . . 16
Overhaul . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Removal from service . . . . . . . . . . . . . . . . . . . . . . . 16
Temporary removal from service . . . . . . . . . . . . . . . . 16
Recommissioning . . . . . . . . . . . . . . . . . . . . . . . . 16
Dismantling and Disposal of the vacuum pump . . . . . . . . . 16
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Spare parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Oil type/ quantity . . . . . . . . . . . . . . . . . . . . . . . . . 22
Oil type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Oil quantity . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Cooling liquid type/ quantity . . . . . . . . . . . . . . . . . . . 23
Cooling liquid type . . . . . . . . . . . . . . . . . . . . . . . 23
Cooling liquid quantity . . . . . . . . . . . . . . . . . . . . . 23
Technical data . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
EU-Declaration of Conformity . . . . . . . . . . . . . . . . . . . 25
Page 2

Introduction
Page 3
Introduction
Congratulations on your purchase of the Busch vacuum pump. With
watchful observation of the field’s requirements, innovation and steady
development Busch delivers modern vacuum and pressure solutions
worldwide.
These operating instructions contain information for
–product description,
–security,
–transport,
–storage,
–installation and commissioning,
–maintenance,
–overhaul,
–troubleshooting
of the vacuum pump.
For the purpose of these instructions, “handling” the vacuum system
means the transport, storage, installation, commissioning, influence on
operating conditions, maintenance, troubleshooting and overhaul of
the vacuum system.
Prior to handling the vacuum system, these operating instructions
shall be read and understood. If anything remains to be clarified
please contact your Busch representative!
Keep these operating instructions and, if applicable, other pertinent
operating instructions available on site.

Product Description
Page 4
Product Description
Use
The COBRA NC vacuum pumps are designed for use in the field of in-
dustrial applications and similar industries.
They can be used to draw gases, gas mixtures and hydrocarbon gases.
WARNING
When using toxic, inflammable and/or explosive gases, make sure
that the system corresponds in design to applicable local and na-
tional safety regulations and that all applicable safety measures are
followed.
All product-specific safety regulations must be observed.
Solid particles must not get into the vacuum pump. Procedural errors
can result in the pump drawing in a certain quantity of liquid. If the
pump has drawn in liquid, a short drying time will be necessary at the
end of the process.
The maximum admissible temperature of drawn gas depends on the
inlet pressure and the nature of the gases. The lower the inlet pressure
(Pa), the higher can be the drawn gas temperature (TGas). We can
consider as air the following indications:
–Pa < 50 mbar, TGas < 200°C
–Pa > 50 mbar, TGas < 70°C
The vacuum pump is thermally suitable for continuous operation at any
pressure between atmospheric pressure and ultimate pressure.
Principle of operation
The COBRA NC vacuum pumps are screw vacuum pumps with cooling
circuit.
The COBRA NC vacuum pumps oparate according to the principle of
screw pumps. Two parallel screws (RT) rotate in opposite directions in
the pump body. Entering gases are trapped between the pitches of the
screws and the pump body. The gases are conveyed by the rotation of
the screws to the exhaust side where they are discharged.
The COBRA NC vacuum pump is driven by an air-cooled motor.
COBRA NC with recirculating cooling system
RT
OIL
Plate heat exchanger
CLEC
OIL
IN
CLRC
OUT
CLRC
CLRC
OFP
CLD
ODP, MP
PMR
IN
CLV
SV
CLP
OSG
TSA
CLSG
TM
OSG
OUT
CLI
EV
ODP
,
MP
TR
CLO
HE
CLI External cooling liquid inlet
CLO External cooling liquid outlet
OFP Oil filler plug
OSG Oil sight glass
ODP Oil drain plug
CLSG Cooling liquid sight glass
MP Magnetic plug
EV Expansion vessel
PMR Plug for manual rotation of rotors
SV Safety valve
CLF Cooling liquid filler plug
CLV Cooling liquid vent plug
CLD Cooling liquid drain plug
TM Thermometer
TR Temperature regulator
HE Plate heat exchanger
TSA Resistance thermometer PT 100
IN Inlet connection
OUT Outlet connection
OIL Oil
CLRC Cooling liquid
(recirculating cooling)
CLEC Cooling liquid
(external cooling)
RT Screw rotors
OFP
TR
ODP,
MP
PMR
CLD
OSG
CLO
CLD
CLI
HE
TM
SV
TSA
IN
OUT
OSG
CLF, CLV
EV
OFP
CLSG
ODP,
MP

Principle schema
Cooling
The vacuum pump is cooled using a cooling liquid (water-glycol mix-
ture) in the water chambers (CLRC) of the cylinder and the outlet side
endplate (A-side). This indirect circuit is done using an integrated recir-
culating pump.
The cooling liquid is cooled by a plate heat exchanger (w) which must
be connected up to the cooling liquid supply (CLEC).
The cooling circuit is equipped with a temperature regulator (u) fitted
upstream of the plate heat exchanger (HE). When the cooling liquid
temperature exceeds 40°C, the temperature regulator opens (mechani-
cal opening) and allows the cooling liquid to flow into the heat exchan-
ger.
The thermometer (TM) allows a visual display of the cooling liquid
temperature inside the cylinder of the vacuum pump.
The relief valve (SV) prevents excessively high pressure in the cylinder
relief pressure: 6 bar.
The resistance thermometer PT 100 (TSA) enables the monitoring of
the endplate gas temperature. When the temperature exceeds the ad-
justed trip value (see values page 10), the pump must be switched off.
NOTE:
The COBRA NC vacuum pumps are always shipped without oil, ex-
ternal cooling liquid and cooling liquid. Operation without any of
these lubricants will destroy the vacuum pump within a short period
of time.
Sealing systems
The COBRA NC vacuum pumps are equipped with oil lubricated single
mechanical seals on the motor side (A-side) and inlet side (B-side) as
standard.
On/ Off switch
The vacuum pump is delivered without on / off switch. The control of
the vacuum pump must be provided in the course of the installation.
Safety
Intended use
DEFINITION: For the purpose of correct understanding, the “handling”
of the vacuum pump implies the transport, storage, installation, com-
missioning, the influence on operating conditions, maintenance, trou-
bleshooting and overhaul of the vacuum pump.
The vacuum pump is intended for industrial use. It should only be han-
dled by qualified staff.
The different applications for use and operational limits of the vacuum
pump as laid out in the “Product Description” and the “Installation
Prerequisites” of the vacuum pump must be observed both by the ma-
nufacturer of the machinery into which the vacuum pump is to be in-
corporated and by the end user.
The need for personal safety regulations depends mainly on the appli-
cation the pump will be used in. The end user must provide the opera-
tors with all necessary means and tools and must inform his personnel
about any dangers emanating from the processed products.
The operator of the vacuum pump must observe the safety regulations
and must train and instruct his personnel accordingly.
Local regulations regarding the motors and electric control elements
must be observed when installing the pump in potentially explosive
environments.
The maintenance instructions must be observed and respected.
Is is vital that these installation and maintenance instructions are read
and understood before the vacuum pump is used. If you have any
doubts, please contact your local Busch representative.
Safety information
The vacuum pump has been designed and manufactured in accordance
with the latest technical and safety standards. Nevertheless, residual
risks may remain.
A lot of safety information is mentioned in these Installation and Ope-
rating Instructions as well as on the pump. The safety instructions must
be observed. The safety information can quickly be detected through
key words like DANGER, WARNING and CAUTION and is defined as
follows:
DANGER
Disregard of this safety note will always lead to accidents with po-
tentially fatal injuries and serious damages.
WARNING
Disregard of this safety note may lead to accidents with potentially
fatal injuries and serious damages.
CAUTION
Disregard of this safety note will always lead to accidents with minor
injuries and damages to property.
Safety
Page 5
T

Safety stickers
Noise emission
For the sound pressure level in free field according to EN ISO 2151, see
“Technical Data”.
CAUTION
The vacuum pump emits noise of high intensity.
Risk of damage to the hearing.
Persons staying in the vicinity of a non noise insulated vacuum pump
over extended periods shall wear ear protection.
Safety area
Before any maintenance action, ensure a safety perimeter of at least 1
[m] around the pump.
Stopping procedure for maintenance
lStop the vacuum pump
lSwitch off power supply (the vacuum pump must be fully disconnec-
ted from any power supply)
lDisconnect external cooling liquid connections (inlet first, then ou-
tlet)
lPut up label or warning board “Maintenance in progress” on or next
to the pump.
Start-up procedure after maintenance
lRemove label or warning board “Maintenance in progress”
lCheck cooling liquid level according to the chapter “Checking the
cooling liquid level”
lCheck oil level according to the chapter “Checking the oil level”
lSwitch on power supply (the vacuum pump must be connected to
the power supply)
lConnect the external cooling liquid connections (outlet first, then in-
let)
lCheck that the “Installation prerequisites” are observed
lStart the vacuum pump
Transport
The COBRA NC vacuum pumps are tested and checked in our factory
before careful packing. Check the packaging for transport damage when
the goods arrive. The pump can withstand temperatures betweeen
-25°C and +55°C during transport.
Transportation of packaged pump
Packed on a pallet, the vacuum pump can be transported with a forklift.
Transport in unpacked state
The vacuum pump is bolted to a pallet or a base plate:
uRemove the bolts between the vacuum pump and the pallet or
base plate
CAUTION
Do not walk, work or stand under suspended loads.
CAUTION
Please check out the weight of the vacuum pump before lifting it up
(see "Technical Data").
Use adequate lifting gear for this.
NOTE: The eyebolts are fitted more or less at equal distance from the
centre of gravity of the vacuum pump incl. drive motor. If any accesso-
ries that could upset the balance of the vacuum pump, are installed, or if
the vacuum pump is delivered without drive motor, it is necessary to add
a belt or rope at a suitable point when lifting the pump.
lAttach lifting gear securely to the eyebolt or eyebolts
lUse lifting gear with a crane hook equipped with safety latch.
lLift the vacuum pump
In case the vacuum pump was bolted to a pallet with fixing bolts:
uUnscrew the fixing bolts in the base frame
CAUTION
If the vacuum pump has already been filled up with oil, make sure
that during lifting, the pump is not inclined more than 5°. There will
otherwise be a risk of oil spilling into the process chamber if the pump
is inclined by more than 5°.
Prior to every transport that needs an appropriate lifting device, control
and monitor the inclination of the vacuum pump (< 5°).
The packaging material must be disposed of in accordance with local and
national regulations.
Transport
Page 6

Storage
Short-term Storage
lMake sure that the inlet / discharge connections are closed (leave
the provided plugs in the pump)
lStore the vacuum pump
–if possible in its original packaging,
–indoors,
–dry,
–in a dust free room and
–free from vibrations
Removal from storage
Before starting up a vacuum pump that has been stored outside the
building for a while, the vacuum pump must be moved to a room with
ambient temperature, where it should rest for a day.
Conservation
In case of adverse ambient conditions (e.g. aggressive atmosphere, fre-
quent temperature changes) conserve the vacuum pump immediately.
In case of favourable ambient conditions conserve the vacuum pump if
a storage of more than 3 months is anticipated.
lMake sure that all openings are hermetically sealed; use adhesive
tape to fasten loose parts (such as o- rings, flat seals, etc.).
lWrap the vacuum pump in VCI film
NOTE: VCI is the abbreviation for “volatile corrosion inhibitor”. The
VCI molecule is an organic corrosion inhibitor in the vapour phase.
Integrated in various carriers such as film, cardboard, paper, foam, li-
quid and powder, it protects parts against corrosion as a result of its
action in vapour phase. However, VCI packaging can attack plastic sur-
faces and surfaces of other elastomers. If in doubt, please contact your
nearest distributor. VCI packaging provides several years of protection
against corrosion, even under harshest conditions: overseas shipment,
extended storage before use.
lStore the vacuum pump
–if possible in its original packaging,
–indoors,
–dry,
–in a dust free and
–vibration free area
Starting-up of the vacuum pump after storage
lPlease ensure that all protective agents such as gaskets, plugs or
adhesive tapes that were used for the protection of the pump, are
removed.
lCommission the vacuum pump as described in chapter “Installa-
tion and Commissioning”
Installation and
Commissioning
Installation prerequisites
CAUTION
In case of non-compliance with the installation prerequisites, parti-
cularly in case of insufficient cooling:
Risk of damage or destruction of the vacuum pump and its compo-
nents!
Risk of personal injury!
The installation prerequisites must be complied with.
lPlease ensure that the integration of the vacuum pump is com-
pliant with the safety requirements of the Machine Directive
2006/42/EC (concerning the responsibility of the system’s manu-
facturer into which the vacuum pump is to be incorporated, please
also refer to the note in the EC-Declaration of Conformity).
WARNING
Local regulations regarding the motors and electric control ele-
ments must be observed when installing the pump in potentially
explosive environments. Before start- up, make sure that all safety
measures have been followed.
Local installation
lMake sure that the environment of the vacuum pump is not po-
tentially explosive
lMake sure that the following ambient conditions are adhered to:
–Ambient pressure: atmospheric
–Humidity range: 20 à 95%
–Altitude: up to 1000 m
lMake sure that the external cooling liquid fulfills the following re-
quirements:
–Temperature: 5 - 25 °C
–Liquid pressure: 1 - 6 bar (relative)
–Flow rate: min. 10 l/min
lMake sure that the external cooling liquid is neutral and clean
lMake sure that the external cooling liquid outlet is unpressurised
lMake sure that the environment conditions correspond to the pro-
tection class of the motor (according to motor nameplate)
lMake sure that the vacuum pump is placed on or fastened to a ho-
rizontal surface
lMake sure that the vacuum pump is level and even
lMake sure that the vacuum pump cannot inadvertently or intentio-
nally be used as a support for heavy objects
lMake sure that the vacuum pump cannot be hit by falling objects
lMake sure that the vacuum pump is at least 1 m away from any
wall
lMake sure that the vacuum pump is easily accessible and that the
selected installation site fulfills the requirements for assembly /
dismantling
lMake sure that no temperature-sensitive part (such as plastic,
wood, cardboard, paper, electronic parts) come into direct contact
with the hot surfaces of the vacuum pump
lMake sure that the installation site or assembly area is ventilated in
such a way that adequate cooling of the vacuum pump is assured
CAUTION
During operation the surface of the vacuum pump may exceed tem-
peratures of 80° C.
Risk of burns!
lMake sure that the vacuum pump cannot be touched inadvertently
during operation, provide a guard if necessary
lMake sure that the oil sight glasses (OSG) will remain easily acces-
sible
If the oil change is meant to be performed on site:
uMake sure that the oil drain plugs as well as the oil filler plugs,
are easily accessible.
Storage
Page 7

Suction Connection
lMake sure that the protection that prevents the ingress of foreign
matter during transport, has been removed before connecting up
the vacuum pump to the piping.
CAUTION
Do not put hands into the inlet aperture.
Risk of body damage!
CAUTION
The ingress of foreign objects or liquids can destroy the vacuum
pump.
In case the inlet gases can contain dust or other foreign solid particles:
uMake sure that a suitable filter or protection screen is installed
at the inlet of the vacuum pump
lMake sure that the nominal diameter of the inlet line is at least
equal to the diameter of the inlet flange to prevent a drop in the
performance of the vacuum pump in the case of a smaller
cross-section.
lMake sure that the vacuum pump is connected with leak proof li-
nes.
CAUTION
Once the inlet line has been connected up, make sure that the sys-
tem does not leak. Leakage of dangerous substances must be pre-
vented!
lMake sure that the inlet line is equipped with a shut-off device
upstream of the inlet flange, so that the flow of drawn gases can
be stopped
lMake sure that the inlet line does not exercise any load on the inlet
flange. Use bellows if necessary.
lThe inlet flange has the following dimension:
NC 0200 B DN 50 PN 16
NC 0300 B DN 50 PN 16
In case of long inlet lines the pipe diameter should be larger than the
inlet flange to prevent a drop in the performance of the vacuum pump.
If you have any doubts, contact your Busch representative.
Discharge connection
CAUTION
Do not put hands into the outlet aperture.
Risk of body damage !
The following instructions for connection to the discharge side only ap-
ply if the drawn gas is discharged into a suitable environment by the
vacuum pump.
lMake sure that the protection, that was fitted to prevent the in-
gress of particles during transport, has been removed before the
vacuum pump is connected up to the vacuum pipe
lMake sure that the nominal diameter of the discharge line corres-
ponds at least to the diameter of the exhaust flange of the vacuum
pump in order to prevent a drop in the performance of the vacuum
pump, in case of use of a smaller cross-section
CAUTION
When the discharge piping has been connected up, make sure that
the system does not leak. Leakage of dangerous substances must be
prevented!
lMake sure that the discharge line is fitted in such a way so as to
prevent any liquids or condensates to re-enter the vacuum pump
(siphon, discharge line sloping away from the pump)
lMake sure that the discharge line is not equipped with a shut-off
lMake sure that the discharge line does not exercise any load on
the exhaust flange. Mount bellows if necessary
lThe outlet flange has the following dimension:
NC 0200 B DN 50 ø85 / 8 x M8
NC 0300 B DN 50 ø85 / 8 x M8
lMaximal counter pressure at the discharge:
–0,2 bar
In the case of long discharge lines, the line cross-section should be lar-
ger than the exhaust flange in order to prevent a drop in the perfor-
mance of the vacuum pump. If you have any doubts, contact your
Busch representative.
External cooling liquid connections
The external cooling liquid is connected up with a flexible or rigid hose
(diameter min. 1/2").
WARNING
Do not exert any force on the connection of the heat exchanger
during assembly and when in operation.
The external cooling liquid outlet must be unpressurised.
Connection diameter:
–External cooling liquid inlet: G1/2", ISO 228
–External cooling liquid outlet: G1/2", ISO 228
Fitting the drive motor
When fitting or replacing the drive motor observe the assembly proce-
dure for the coupling.
WARNING
Prior to fitting the coupling, it is imperative that the coupling manu-
facturer’s operating instructions are read and understood. If in any
doubt, please contact your local Busch representative or consult the
coupling manufacturer’s internet site: www.ktr.de
CAUTION
During assembly of the coupling, make sure that value E is adhered
to (refer to the drawing below). The coupling spider must remain
axially free during operation.
When value E is not followed, the coupling can be damaged.
Installation and Commissioning
Page 8

Fitting the coupling
Type Size Value E [mm]
NC 0200 B 38 24
NC 0300 B
lFit the coupling hubs onto the respective shafts of the vacuum pump
and the drive motor.
lAxially move the unit motor/ coupling hub in such a way until value
E is reached.
If the unit motor/coupling hub is already fitted:
uMove the coupling hubs on the shafts in order to reach value E
lLock the coupling hubs by tightening the set screws
uTightening torque: 10 Nm
Control intervals
After 2000 operating hours or after 3 months at the latest, an inspection
for torsional play must be conducted and a visual check of the spider (2)
must be done.
In case of negligible or no wear at all at the spider (2) after this first ins-
pection, the next inspections can be done after 4000 operating hours or
at the latest after 12 months, if the same operating parameters prevail.
If considerable wear is detected during the first inspection, meaning that
a replacement of the spider is necessary, find out the cause in the origi-
nal manual of the supplier. The original version is available on the inter-
net under: www.ktr.de.
When there is considerable wear, the maintenance intervals must be
adapted to the new operating conditions. The gap between the hubs
and the spider (2) must be checked with a feeler gauge.
When the maximum wear limit is reached (Xmax), the spider must be re-
placed immediately, regardless of the inspection intervals.
Type Size Limit of wear Xmax [mm]
NC 0200 B 38 3
NC 0300 B
Axial displacement
When fitting/ replacing the motor or during maintenance work on the
coupling, assembly tolerances have to be respected in order to prevent
axial displacement.
Type Size A [mm] Tolerance [mm]
NC 0200 B 38 3±0,9
NC 0300 B
Electrical connection/ Checks
lMake sure that the requirements according to EMC-Directive
2014/30/EU as well as the current EN-standards, electrical and occu-
pational safety directives and the local or national regulations respec-
tively, are complied with (this is the responsibility of the designer of
the machinery into which the vacuum pump is to be incorporated;
see also the corresponding comments in the EC-Declaration of
Conformity).
lMake sure that the power supply is compatible with the data on the
nameplate of the drive motor
lMake sure that an overload protection according to EN 60204-1 is
provided for the drive motor
lMake sure that the drive of the vacuum pump will not be affected
by electric or electromagnetic interference; if unsure please seek ad-
vice from your Busch representative
Installation and Commissioning
Page 9
Nabe (1a)
hub (1a)
moyeu (1a)
Fühlerlehre
feeler gauge
cale
Zahnkranz (2)
spider (2)
anneau (2)
Nabe (1)
hub (1)
moyeu (1)
B = Neuzustand
B = new state
B = nouvel état
X = Verschleiss
X = wear and tear
X = usure
Richwert/Verdrehspiel
approximate value/circumferential backlash
valeur indicative/jeu de torsion
A
A

Resistance thermometer PT 100 (TSA)
The resistance thermometer PT 100 (TSA) enables the monitoring of
the endplate gas temperature. When the temperature exceeds the ad-
justed trip value, the pump must be switched off (see values bellow)
Resistance thermometer PT 100 (TSA)
Pump type signal value [°C]
NC 0200 B 115
NC 0300 B 130
Technical data
Technical data Resistance thermometer
Type TWBa-ADAXXDACB
Supplier Balzer - Rotax
Supply voltage 30 VDC
Type of protection Ex ia IIC T1...T6
Approval PTB 01 ATEX 2206 X
Tube material 1.4571
Nominal temperature range - 200...+ 400 °C
Electrical wiring
Installation
Fitting
lMake sure that the “Installation Prerequisites” are complied with
lFit or install the vacuum pump at its final location
Electrical connection
WARNING
Risk of electrical shock, risk of damage to equipment.
Electrical installation work must only be executed by qualified per-
sonnel that knows and observes the following regulations:
- IEC 364 or CENELEC HD 384 or DIN VDE 0100, respectively,
- IEC-Report 664 or DIN VDE 0110,
- BGV A2 (VBG 4) or corresponding national accident prevention
regulation.
CAUTION
The connection schemes given below are typical. Specific orders or
deviating connection schemes for certain markets may apply.
Risk of damage to the drive motor!
Please check drive motor connections inside the terminal box and
refer to the drive motor connection instructions.
lConnect the drive motor electrically
lConnect the earth line
Delta connection (Low voltage):
Star connection (High voltage):
CAUTION
Operation of the pump in the wrong direction of rotation, even for
a short period of time, can destroy the vacuum pump.
Risk of explosion of the drive motor!
Prior to starting-up of the vacuum pump, please ensure that the va-
cuum pump is connected up correctly.
lDetermine the direction of rotation with the arrow sign on the fan
cover of the motor (see image "Safety stickers").
Installation and Commissioning
Page 10
PE
-
+
With transmitter (optional supply)
Red
Red
White
White
L1 L2
L3
U1
U2
V1
V2
W1
W2
U1 U2
L1
V1 V2
L2 W1 W2
L3
Without transmitter (standard supply)
RedRed
White White
Red
Red
White
White
U1 U2
L1
V1 V2
L2
W1 W2
L3
L1 L2
L3
U1
U2
V1
V2
W1
W2

lPress the start button and hold briefly
lWatch the fan of the drive motor and determine the direction of
rotation just before the fan stops
If the fan is turning in the wrong direction:
uSwitch around any two of the drive motor wires in the terminal
box
Connecting up of lines/ pipes
lConnect the suction line
lConnect the discharge line
lMake sure that all provided covers, guards, hoods etc. are fitted
Filling up with oil
CAUTION
It is possible that the vacuum pump was tested with an oil type dif-
ferent from the recommended type. The vacuum pumps tested with
a special oil are dispatched with specific stickers (“Special Oil”) si-
tuated on the gear housing and on the cylinder cover, inlet side
(B-side).
If the oil types are not compatible, please carry out a clean-out of all
parts having been in contact with the old oil.
Make sure that the bearings are lubricated before re-assembly .
The COBRA NC vacuum pumps are always delivered without oil (see
chapter “Oil Type” for information on recommended oils).
lPrepare the quantity of oil specified in the table “Oil quantity”
NOTE: The quantity of oil specified in the operating instructions is of
informative nature only. Check the oil level with the help of the various
oil sight glasses (OSG) on the vacuum pump.
CAUTION
Before changing the type of oil, make sure that the new type is
compatible with the old type. If necessary, flush the vacuum pump.
lUnscrew the oil filler plugs (OFP)
lFill in oil
lMake sure that the filling level is about 3 mm above the middle of
the oil sight glasses (OSG)
lMake sure that the seal ring in the oil filler plugs is not damaged,
replace plugs if necessary
lFit the oil filler plugs and tighten up
NOTE: Starting the vacuum pump when the oil is cold is made easier
when the suction line is left open or the rubber mat is removed.
lSwitch on the vacuum pump
In case the suction line is equipped with a shut-off valve:
uClose the shut-off valve
In case the suction line is not equipped with a shut-off valve:
uCover the inlet connection with a rubber mat
lLet the vacuum pump run for a few minutes
lSwitch of the vacuum pump and wait for a few minutes
lCheck that the filling level is always approximately 3 mm above
the middle of the oil sight glasses (OSG)
If the oil level is below the middle of the oil sight glasses:
uTop-up with oil
In case the suction line is equipped with a shut-off valve:
uOpen the shut-off valve
In case the suction line is not equipped with a shut-off valve:
uRemove the rubber mat from the suction flange and connect
the suction line to the suction flange
CAUTION
If the vacuum pump has already been filled up with oil, make sure
that during lifting, the pump is not inclined more than 5°. There will
otherwise be a risk of oil spilling into the process chamber if the
pump is inclined by more than 5°.
Prior to every transport that needs an appropriate lifting device, control
and monitor the inclination of the vacuum pump (< 5°).
CAUTION
The vacuum pump must remain in a horizontal position once it has
been filled with oil.
Filling in cooling liquid
The COBRA NC vacuum pumps are always delivered without cooling
liquid (see chapter “Cooling liquid types ” for information on the re-
commended cooling liquids).
lPrepare the quantity of cooling liquid as specified in the table
“Cooling liquid quantity”
NOTE: The quantity of cooling liquid specified in the installation hand-
book is of informative nature only. Follow the procedure of filling the
cooling liquid.
lRemove the cooling liquid filler plug (CLF) on the expansion tank
lRemo ve the cooling liquid vent plug (CLV) on the expansion tank
lFill in cooling liquid through the filler hole until the level is in the
middle of the cooling liquid sight glass (CLSG)
lStop filling in
lRefit the cooling liquid vent plug
lRefit the cooling liquid filler plug and tighten up
lIf there has been any spillage on the surface of the expansion tank,
wipe it up
lStart the vacuum pump
If the inlet line is equipped with a shut-off valve:
lClose the shut-off valve
If the inlet line is not equipped with a shut-off valve:
lPlace a rubber mat on the inlet flange
lLet the vacuum pump run for no more than 5 minutes
lStop the vacuum pump and wait for a few minutes
lRemove the cooling liquid vent plug (CLV), let the air escape and
refit the cooling liquid vent plug
lCheck that the cooling liquid level is still in the middle of the coo-
ling liquid sight glass (CLSG)
If the cooling liquid level is below the required level:
uFill in more cooling liquid
If the inlet line is equipped with a shut-off valve:
uOpen the shut-off valve
If the inlet line is not equipped with a shut-off valve:
lRemove the rubber mat from the inlet flange and connect the inlet
line to the inlet flange
Connection of the external cooling liquid
supply
Make sure that the external cooling liquid fulfills the following require-
ments:
–Temperature: 5 - 25 °C
–Liquid pressure: 1 - 6 bar (relative)
Installation and Commissioning
Page 11

–Flow rate: min. 10 l/min
lMake sure that the external cooling liquid is neutral and clean
lMake sure that the external cooling liquid outlet is unpressurised
lConnect the external cooling liquid supply to the external cooling
liquid inlet (CLI)
lConnect the external cooling liquid outlet (CLO)
lOpen the external cooling liquid supply
uFill up the plate heat exchanger with external cooling liquid
Saving the operating parameters
As soon as the vacuum pump has been working for 30 minutes under
normal conditions after having been switched on:
lMeasure the working current of the motor and keep it as reference
value for all future maintenance and repair work
Recommendations on operation
Application
WARNING
The vacuum pump is designed for operation under the conditions
described below.
In case of disrespect of the above, risk of damage or destruction of
the vacuum pump!
The vacuum pump must only be operated under the conditions
described below.
The COBRA NC vacuum pumps have been designed for use in indus-
trial applications and similar industries.
They can be used to draw gases, gas mixtures and hydrocarbon gases.
WARNING
When using toxic, inflammable and/ or explosive gases, make sure
that the system corresponds to applicable local and national safety
regulations and that all applicable safety measures are followed.
All product-specific safety regulations must be observed.
Solid particles must not enter the vacuum pump. In case of process er-
rors, the pump can draw in a certain amount of liquids.
The vacuum pump is thermally suitable for continuous use at any pres-
sure between atmospheric pressure and ultimate pressure.
CAUTION
During operation the surface of the vacuum pump can exceed tem-
peratures of 80°C.
Risk of burns!
The vacuum pump must be protected against contact during opera-
tion. If touching the pump is unavoidable, wait until the surface
temperature has cooled down or wear protective gloves.
CAUTION
The sound level of the pump within a certain perimeter of the pump
is high.
Risk of hearing damage.
Users, who are spending a longer period of time in the vicinity of a
non-insulated vacuum pump, must wear suitable ear protection.
NOTE
The COBRA NC vacuum pumps are usually dispatched without the
oil and cooling liquid (recirculating cooling system) already filled in.
Prior to commissioning the vacuum pump, please check the different
levels at the sight glasses on the vacuum pump. If one of the liquids
is absent, please fill it in (consult the relevant chapter). Operation
without one of these liquids can damage or destroy the vacuum
pump.
lMake sure that all provided covers, guards, hoods etc. remain fit-
ted
lMake sure that protective devices will not be disconnected
lMake sure that there is no leakage in the system, the escape of
dangerous substances must be avoided
lMake sure that the “Installation Prerequisites” are complied with
and will remain so, and ensure that adequate cooling is guaranteed
lMake sure that, prior to commissioning or after a longer standstill
period of the vacuum pump, the expansion tank of the recircula-
ting cooling system is filled with enough cooling liquid.
lMake sure that, prior to commissioning or after a longer standstill
period of the vacuum pump, the external cooling liquid volume
flow of the cooling system is adjusted correctly
If the pump is shut down for a longer period of time:
–Drain the cooling liquid
uOpen the cooling liquid vent plug (CLV)
uUnscrew the cooling liquid drain plugs (CLD)
uDrain the cooling liquid completely
uRefit the cooling liquid drain plugs again
uClose the cooling liquid vent plug
uCollect the cooling liquid and re-use it or dispose of it accor-
ding to local or national regulations
NOTE: When the pump has not been in operation for a few days or
when a sticky substance has been drawn, it is possible that the two ro-
tor screws of the COBRA NC vacuum pump are stuck to each other.
Unscrew the access cover (situated on the cylinder cover at the inlet
side (B-side). Free the rotors with an Allen key and an extension by tur-
ning them clockwise by hand. Switch on the vacuum pump and flush
it.
Switching the vacuum pump on/ off
First start-up of the system
lMake sure that the “Installation Prerequisites” are followed
If the vacuum pump is equipped with a shut-off valve at the inlet:
uOpen the shut-off valve
If the system is equipped with a solenoid valve on the external cooling
liquid circuit:
uOpen the solenoid valve
lOpen the external cooling liquid supply
lStart the vacuum pump
Switching off the system
lSwitch off the vacuum pump
lClose the external cooling liquid supply
If the vacuum pump is equipped with a solenoid valve on the external
cooling liquid circuit:
uClose the solenoid valve
If the vacuum pump is equipped with a shut-off valve at the inlet:
uClose the shut-off valve
lThe system must be disconnected from the power supply
Installation and Commissioning
Page 12

Maintenance
DANGER
In case the vacuum pump has conveyed gases that have been
contaminated with foreign materials that are dangerous to health,
the oil and condensates will also be contaminated.
These foreign materials can infiltrate the pores, recesses and other
internal spaces of the vacuum pump.
Danger to health when the vacuum pump is dismantled.
Danger to the environment.
Always wear protective clothing when carrying out maintenance
work.
Before any maintenance work, the inlet and outlet piping as well as
the vacuum pump itself must be flushed with nitrogen.
CAUTION
Only authorised personnel may carry out any dismantling on the va-
cuum pump. Before work begins, the operator of the vacuum pump
must fill in a form or a “Declaration Regarding Contamination of
Vacuum Equipment and Components” that provides information on
possible dangers and appropriate measures.
If this form has not been filled in completely and signed by a res-
ponsible person, the vacuum pump may not be dismantled.
CAUTION
Before any maintenance work is started, a safety perimeter of at
least 1 [m] around the machine must be set up.
CAUTION
During operation the surface of the vacuum pump may reach tem-
peratures in excess of 80 °C.
Risk of burns!
Before starting any maintenance work, make sure that the vacuum
pump has been fully switched off and that it cannot accidentally be
switched on again. Follow the shutdown procedure in the section
“Stopping procedure for maintenance”:
lStop the vacuum pump
lSwitch off the power supply (the vacuum pump must be fully dis-
connected from the power supply)
lDisconnect the external cooling liquid connections (inlet first, then
outlet)
lPut up label or warning board “Maintenance in progress” on or
next to the pump
CAUTION
The oil temperature can reach a value of 100°C!
Danger of burns!
lMake sure that any cleaning materials used to clean the vacuum
pumps have been disposed of according to local and national regu-
lations
Before disconnecting the different connections, make sure that the inlet
and exhaust lines of the vacuum pump have been brought to atmos-
pheric pressure
When the maintenance work has been finished, follow the procedure
“Start-up procedure after maintenance”:
lRemove the label or warning board “Maintenance in progress”
lCheck the cooling liquid and oil levels according to chapters
“Checking the oil level” and “Checking the cooling liquid level”
lConnect the pump up to the power supply
lReconnect the external cooling liquid connections (outlet first, then
inlet)
lMake sure that the “Installation Prerequisites” are followed
lStart the pump
Maintenance program
NOTE: The maintenance intervals depend a lot on the individual opera-
ting conditions. The intervals given below should be considered initial
guidelines which ought to be shortened or extended as appropriate. In
particularly heavy duty operation such as high dust loads in the envi-
ronment or in the process gas, it may become necessary to shorten the
maintenance intervals significantly.
Monthly:
lCheck the oil level (see “Checking the Oil”)
lCheck the level of the cooling liquid (see “Checking the Cooling li-
quid”)
lCheck the temperature of the cooling liquid (see “Checking the co-
oling liquid”)
lCheck the temperature and the volume flow of the external coo-
ling liquid (see “Checking the external cooling liquid” )
lCheck the vacuum pump for oil leaks - in case of leaks, have the
vacuum pump repaired (Busch service)
lCheck the vacuum pump for cooling liquid leaks - in case of leaks,
have the vacuum pump repaired (Busch service)
lCheck the vacuum pump for external cooling liquid leaks - in case
of leaks, have the vacuum pump repaired (Busch service)
Yearly:
In case of operation in a dusty environment:
uMake sure that the operating room is clean and free of dust;
clean the room if necessary
lMake sure that the vacuum pump has been switched off and that
it cannot accidentally be switched on again
lCheck the electrical connections
lCarry out a visual inspection of the vacuum pump
If the inlet is equipped with a mesh screen:
uCheck the mesh screen at the inlet and clean it if necessary
lCheck the correct operation of the measurement and safety equip-
ment
Every 5000 operating hours:
lChange the oil (see “Changing the Oil”)
lChange the cooling liquid (see “Changing the cooling liquid”)
If an filter is installed on the external cooling liquid line:
uCheck the filter, clean or replace it, if necessary
Every 10’000 operating hours:
lCheck the seals and replace them if necessary
lCheck the inlet and discharge lines and clean or replace them if ne-
cessary
lCheck the external look of the mechanical seals. If they are worn
or damaged, replace them.
lThe mechanical seals use small quantities of oil, max. 1,5 cm3per
month; a higher consumption indicates a malfunction of the me-
chanical seals
Maintenance
Page 13

Every 16’000 operating hours, at the latest
after 4 Years:
Have a major overhaul done on the vacuum pump (Busch service)
Stopping procedure for maintenance
lStop the vacuum pump
lSwitch off the power supply (the vacuum pump must be discon-
nected from the power supply)
lDisconnect the external cooling liquid connections (inlet first, then
outlet)
lPut up label or warning board “Maintenance in progress” on or
next to the pump.
Start-up after maintenance
lRemove label or warning board “Maintenance in progress”
lCheck the oil level according to the chapter “Checking the oil le-
vel”
lCheck the cooling liquid level according to the chapter “Checking
the cooling liquid level”
lConnect the pump up to the power supply
lReconnect the external cooling liquid connections (outlet first, then
inlet)
lMake sure that the “Necessary installation instructions” are follo-
wed
lStart the vacuum pump
Checking the oil
CAUTION
It is possible that the vacuum pump was tested with an oil type dif-
ferent from the recommended type. The vacuum pumps tested with
a special oil are dispatched with specific stickers (“Special Oil”) si-
tuated on the gear housing and on the cylinder cover, inlet side
(B-side).
If the oil types are not compatible, please carry out a clean out of all
parts having been in contact with the old oil.
Make sure that the bearings are lubricated before reassembly .
Checking the oil level
lMake sure that the vacuum pump is switched off and cannot acci-
dentally be switched on again
lCheck the oil level on the different oil sight glasses
If the oil level is below the required level:
uTop up with oil (see “Topping up Oil”)
If the oil level is above the required level:
uCheck the evacuation of the condensates
uChange the oil (see “Change the oil”)
Topping up with oil
NOTE: Under normal conditions there should be no need to top up
with oil in-between the recommended oil change intervals. A signifi-
cant drop in the oil level indicates a malfunction (see “Troubleshoo-
ting”).
CAUTION
Fill in oil only through the oil filler holes.
CAUTION
Risk of injury (burns) with open oil filler orifice.
Risk of injury in case of badly screwed-in plugs.
Remove the oil filler plugs only when the vacuum pump is stopped.
The vacuum pump must only be operated when the oil filler plugs
are firmly tightened up and do not leak.
lMake sure that the vacuum pump is switched off and cannot acci-
dentally be switched on again
lRemove the oil filler plugs (OFP)
lTop up with oil
lMake sure that the oil level is 3 mm above the middle of the oil
sight glass
lMake sure that the seals of the oil filler plugs are not damaged and
replace plugs if necessary
lRefit the oil filler plugs and tighten up
Life-span of the Oil
The oil life depends very much on the operating conditions. Under nor-
mal conditions the oil must be changed every 5000 operating hours or
after six months, whichever comes first.
Under very unfavourable operating conditions the oil life can be less
than 500 operating hours. A very short oil life time indicates either a
malfunction (see “Troubleshooting”) or unsuitable operating
conditions.
If there is no experience available regarding the oil life under the pre-
vailing operation conditions, it is recommended to have the oil analy-
sed every 500 operating hours and thus to establish the oil change
interval accordingly.
Changing the oil
DANGER
In case the vacuum pump has conveyed gases that have been
contaminated with harmful foreign materials, the oil will also be
contaminated.
Danger to health during the change of contaminated oil.
Danger to the environment.
Wear protective equipment during the change of contaminated oil.
Contaminated oil is hazardous waste and must be disposed of se-
parately in compliance with applicable regulations.
Draining used oil
NOTE: After switching off the vacuum pump at normal operating tem-
perature wait no more than 20 minutes before the oil is drained.
lMake sure that the vacuum pump is switched off and cannot acci-
dentally be switched on again
lMake sure that the vacuum pump is vented to atmospheric pres-
sure
lPut a drain tray underneath the oil drain plugs (ODP)
lRemove the oil drain plugs (ODP)
lCarefully remove the drain plugs
lDrain the oil
lBecause of wear and tear on the seals replace the current drain
plugs with new ones
When the oil flow has stopped:
uClose the oil drain plugs (ODP)
Maintenance
Page 14

lSwitch on the vacuum pump for a few seconds
lMake sure that the vacuum pump is switched off and cannot acci-
dentally be switched on again
lRemove the oil drain plugs again and drain any remaining oil
lCheck that no metal swarf sticks to the magnet of the drain plug,
clean or change it if necessary
lRefit the oil drain plugs and tighten up
lDispose of the used oil in compliance with applicable regulations
CAUTION
Because the ends of the drain plugs are magnetic, metal swarf can
stick to them. Always clean away this swarf when removing the
drain plugs.
Because of wear and tear of the seals, it is recommended to replace
the drain plugs whenever the oil is changed.
Filling in new oil
lPrepare the quantity of oil needed (see “Oil type/quantity”)
NOTE: The quantity of oil specified in the operating instructions is of
informative nature only. Check the oil level with the help of the various
oil sight glasses on the vacuum pump.
lMake sure that the oil drain plugs have been fitted properly and
that they do not leak
CAUTION
Only fill in oil through the oil filler orifices.
lRemove the oil filler plugs (OFP)
lFill in oil
lMake sure that the oil level is 3 mm higher than the middle of the
oil sight glass
lMake sure that the seals of the oil filler plugs are not damaged and
replace plugs if necessary
lRefit the oil filler plugs and tighten up
Checking the cooling liquid
Checking the level of the cooling liquid
lMake sure that the vacuum pump is switched off and cannot acci-
dentally be switched on again
lCheck the level of the cooling liquid on the cooling liquid sight
glass (CLSG)
The cooling liquid level must be in the middle of the cooling liquid
sight glass
If the level is below:
uTop up with cooling liquid (see “Refilling cooling liquid”)
Checking the cooling liquid temperature
uRegularly check the cooling liquid temperature with the help of
the thermometer (TM) situated on the upper cylinder cover
Topping up with cooling liquid
NOTE: Under normal conditions there should be no need to top up
with cooling liquid in-between the recommended change intervals. A
significant drop in the cooling liquid level indicates a malfunction (see
“Troubleshooting”).
lMake sure that the vacuum pump is switched off and cannot acci-
dentally be switched on again
CAUTION
Wait until pump has cooled down to ambient temperature
lRemove the cooling liquid filler plug (CLF) on the expansion tank
lRemove the cooling liquid vent plug (CLV) on the expansion tank
lFill up until the cooling liquid level is in the middle of the cooling li-
quid sight glass (CLSG)
lStop the filling
lMake sure that the seal of the vent plug is not damaged and re-
place the plug if necessary
lRefit the cooling liquid vent plug
lMake sure that the seal ring of the cooling liquid filler plug is not
damaged, replace plug if necessary
lRefit the cooling liquid filler plug and tighten up
lIf there is any spillage on the surface of the vacuum pump, wipe it
up
Changing the cooling liquid
Draining the cooling liquid
lMake sure that the vacuum pump is switched off and cannot acci-
dentally be switched on again
CAUTION
Wait until pump has cooled down to ambient temperature
lMake sure that the vacuum pump is vented to atmospheric pres-
sure
lPut a drain tray underneath the cooling liquid drain plugs (CLD)
lRemove the cooling liquid vent plug (CLV)
lRemove the cooling liquid drain plugs (CLD)
lDrain the cooling liquid
lRefit the cooling liquid drain plugs again and tighten up
lRefit the cooling liquid vent plug again
lDispose of the used cooling liquid in compliance with applicable re-
gulations
Filling up with new cooling liquid
lPrepare the quantity of cooling liquid needed (see “Cooling liquid
type/ quantity”)
NOTE: The quantity of cooling liquid specified in the operating instruc-
tions is of informative nature only.
lRemove the cooling liquid filler plug (CLF) on the expansion tank
lRemove the cooling liquid vent plug (CLV) on the expansion tank
lFill up through the orifice until the cooling liquid level is in the
middle of the cooling liquid sight glass (CLSG)
lRefit the cooling liquid vent plug (CLV)
lRefit the cooling liquid filler plug and tighten up (CLF)
lIf there is any spillage on the surface of the vacuum pump, wipe it
up
lStart the vacuum pump
If the inlet line is equipped with a shut-off device:
uClose the shut-off device
If the inlet line is not equipped with a shut-off device:
uPlace a rubber mat on the inlet flange
lLet the vacuum pump run for maximum 5 minutes
lStop the vacuum pump and wait for a few minutes
lRemove the cooling liquid vent plug (CLV), allow the air to escape
and refit the plug
lCheck that the cooling liquid level is always in the middle of the
cooling liquid sight glass (CLSG)
Maintenance
Page 15

In case the cooling liquid level is below thhe required level:
uFill in more cooling liquid
If the inlet line is equipped with a shut-off device:
uOpen the shut-off device
If the inlet line is not equipped with a shut-off device:
lRemove the rubber mat from the inlet flange and connect the inlet
line to the inlet flange
Checking the external cooling liquid
lCheck regularly the external cooling liquid temperature
lRegularly check the external cooling liquid volume flow
lMake sure that the specifications of the external cooling liquid are
followed
Checking the current consumption
lCheck the current of the motor
An increased current indicates a fault (see “Troubleshooting”)
Overhaul
CAUTION
Improper maintenance work on the vacuum pump can damage it.
Risk of explosion!
Non-adherence to the procedure will cancel approval for start-up of
the pump!
Any dismantling of the vacuum pump beyond of what is described
in this manual must be done by specially trained Busch service staff
only.
DANGER
In case the vacuum pump has conveyed gases that have been
contaminated with foreign materials that are dangerous to health,
the oil and condensates will also be contaminated.
These foreign materials can infiltrate the pores, recesses and other
internal spaces of the vacuum pump.
Danger to health when the vacuum pump is dismantled.
Danger to the environment.
Prior to shipping, the vacuum pump must imperatively be deconta-
minated and the degree of contamination must be documented in a
declaration of decontamination ("Declaration of Decontamination"),
which can be downloaded from www.buschvacuum.com.
Busch service will only accept vacuum pumps that come with a com-
pletely filled in and legally binding signed form.
Removal from service
Temporary removal from service
Prior to disconnecting inlet and outlet pipes as well as external cooling
liquid pipes, make sure that all piping is vented to atmospheric pressure
Recommissioning
CAUTION
After a long period of inactivity, it is possible that the rotor screws of
the COBRA NC vacuum pump are stuck.
Turn the rotor screws manually.
lMake sure that all gaskets, plugs or adhesive tapes have been re-
moved.
lStart the vacuum pump as described in the chapter “Installation
and Commissioning”
Dismantling and Disposal of the
vacuum pump
DANGER
In case the vacuum pump has conveyed gases that have been
contaminated with harmful foreign material which are harmful to
health, the oil and the condensates will also be contaminated with
harmful foreign material.
These foreign materials can infiltrate the pores, recesses and other
internal spaces of the vacuum pump.
Danger to health during dismantling of the vacuum pump.
Danger to the environment.
During dismantling of the vacuum pump protective equipment and
clothing must be worn.
The vacuum pump must be decontaminated prior to disposal.
Prior to shipping, the vacuum pump must imperatively be deconta-
minated and the degree of contamination must be documented in a
declaration of decontamination ("Declaration of Decontamination"),
which can be downloaded from www.buschvacuum.com.
Used oil and condensates must be disposed of separately in com-
pliance with applicable environmental regulations.
When the vacuum pump comes to the end of its life:
–it must be decontaminated
CAUTION
Only authorised personnel may carry out dismantling work on the
vacuum pump. Before work begins, the operator of the vacuum
pump must fill in a form or a “Declaration of Decontamination” that
provides information on possible dangers and appropriate measures.
If this form has not been filled in completely and signed, the va-
cuum pump may not be dismantled.
–drain the oil
udispose of the used oil in compliance with applicable environ-
mental regulations
with recirculating cooling system:
–drain the cooling liquid
udispose of the cooling liquid in compliance with applicable en-
vironmental regulations
–dismantle the vacuum pump
CAUTION
During dismantling of the vacuum pump protective equipment and
clothing must be worn.
Overhaul
Page 16

udispose of the vacuum pump as scrap metal
–dispose of the different components of the pump in compliance
with applicable regulations
Removal from service
Page 17

Troubleshooting
WARNING
Risk of electrical shock, risk of damage to equipment.
Electrical installation work must only be executed by qualified personnel that knows and observes the following regulations:
- IEC 364 or CENELEC HD 384 or DIN VDE 0100, respectively,
- IEC-Report 664 or DIN VDE 0110,
- BGV A2 (VBG 4) or equivalent national accident prevention regulation.
CAUTION
During operation the surface of the vacuum pump may reach temperatures of more than 80 °C.
Risk of burns!
Let the vacuum pump cool down prior to a required contact or wear heat protection gloves.
Problem Possible Cause Remedy
The vacuum pump does not reach the usual
pressure
The vacuum system or suction line is not
leak-tight
Check the hose or pipe connections for possible
leak
The drive motor draws a too high current (com-
pare with initial value after commissioning)
Process deposits on the pumping components
(the most common cause)
Flush the pump carefully
In case a mesh screen is installed on the suction
connection:
The mesh screen on the suction connection is
partly clogged
Clean the mesh screen
If cleaning is required too frequently install a fil-
ter upstream
In case an inlet filter is installed on the suction
connection:
The filter on the suction connection is partly
clogged
Clean or replace the inlet filter, respectively
Partial clogging in the suction, discharge or
pressure line
Remove the clogging
Long suction, discharge or pressure line with
too small diameter
Use larger diameter
Internal parts worn or damaged Repair the vacuum pump (Busch service)
The vacuum pump does not start The drive motor is not supplied with the correct
voltage or is overloaded
Supply the drive motor with the correct voltage
The drive motor starter overload protection is
too small or trip level is too low
Compare the trip level of the drive motor starter
overload protection with the data on the name-
plate
Correct if necessary
In case of high ambient temperature:
Set the trip level of the drive motor starter
overload protection 5 percent above the no-
minal drive motor current
One of the fuses has blown Check the fuses
The connection cable is too small or too long
causing a voltage drop at the vacuum pump
Use sufficiently dimensioned cable
The vacuum pump or the drive motor is blocked Turn the screws rotors (RT) manually or repair
the vacuum pump (Busch service)
The drive motor is defective Replace the drive motor (Busch service)
Troubleshooting
Page 18

The vacuum pump is blocked Solid foreign matter has entered the vacuum
pump
Repair the vacuum pump (Busch service)
Make sure the suction line is equipped with a
mesh screen
If necessary additionally provide a filter
Corrosion in the vacuum pump from remaining
condensate
Repair the vacuum pump (Busch service)
Check the process
Observe the chapter “Installation and Commis-
sioning, Operating Notes”
The vacuum pump was run in the wrong
direction
Repair the vacuum pump (Busch service)
When connecting the vacuum pump make sure
the vacuum pump will run in the correct direc-
tion (see “Installation”)
Condensate ran into the vacuum pump Repair the vacuum pump (Busch service)
Make sure no condensate will enter the vacuum
pump, if necessary provide a drip leg and a
drain cock
Drain condensate regularly
The recirculating pump is blocked Remove the recirculating pump, clean if neces-
sary
The vacuum pump starts, but labours or runs
noisily or rattles
The drive motor draws a too high current (com-
pare with initial value after commissioning)
Connections in the drive motor terminal box are
defective
Not all drive motor coils are properly connected
The drive motor operates on two phases only
Check the proper connection of the wires
against the connection diagram
Tighten or replace loose connections
The vacuum pump runs in the wrong direction Verification and rectification see “Installation
and Commissioning”, correct if necessary
Standstill over several weeks or months Let the vacuum pump run warm with inlet clo-
sed
Oil viscosity is too high for the ambient tempe-
rature
Use oil with a better viscosity class
Improper oil quantity, unsuitable oil type Use the proper quantity of one of the recom-
mended oils
(see “Oil”, oil change see “Maintenance”)
No oil change over extended period of time Perform oil change incl. flushing (see “Mainte-
nance”)
Foreign objects in the vacuum pump
Stuck bearings
Repair the vacuum pump (Busch service)
The vacuum pump runs very noisily Defective bearings Repair the vacuum pump (Busch service)
Worn coupling element Replace the coupling element
The vacuum pump runs very hot External cooling liquid flow too low Check the external cooling liquid circuit and ad-
just the flow if necessary
Ambient temperature too high Observe the permitted ambient temperatures
Temperature of the inlet gas too high Observe the permitted temperatures for the in-
let gas
Mains frequency or voltage outside tolerance
range
Provide a more stable power supply
In case a mesh screen is installed on the suction
connection:
The mesh screen on the suction connection is
partially clogged
Clean the mesh screen
If cleaning is required too frequently install a fil-
ter upstream
In case an inlet air filter is installed on the suc-
tion connection:
The filter on the suction connection is partially
clogged
Clean or replace the filter
Troubleshooting
Page 19

Partial clogging in the suction or discharge line Remove the clogging
Long suction, discharge or pressure line withtoo
small diameter
Use larger diameter
The oil is black Oil change intervals are too long Drain oil
Fill in new oil
(see “Maintenance”)
Troubleshooting
Page 20