KNF N 920 APE-W Assembly instructions

KNF 121690-121708 09/19
OEM
N920
TRANSLATION OF ORIGINAL OPERATING AND
INSTALLATION INSTRUCTIONS
ENGLISH
DIAPHRAGM
VACUUM PUMP
Note!
Before operating the pump and the accessories, please read the operating instructions and pay attention to
the safety precautions!

Contents Page
1. About this document.................................................................3
2. Use............................................................................................4
3. Safety........................................................................................6
4. Technical Data..........................................................................9
5. Design and function................................................................11
6. Transportation.........................................................................13
7. Installation and connection.....................................................14
8. Operation................................................................................20
9. Servicing.................................................................................32
10. Troubleshooting......................................................................37
11. Spare parts and accessories..................................................39
12. Returns ...................................................................................40
KNF Neuberger GmbH
Alter Weg 3
79112 Freiburg
Germany
Phone [phone]
Fax [phone]
E-mail: [e-mail]
www.knf.de

Vacuum Pumps N 920 APE-W and N 920 APDC-B About this document
Original-Operating and Installation Instructions, english, KNF 121690-121708 09/19 3
1. About this document
1.1. Using the Operating and Installation
Instructions
The Operating and Installation Instructions are part of the pump.
➔Always keep the Operating and Installation Instructions handy
in the work area.
➔Pass on the Operating and Installation Instructions to the next
owner.
Customer-specific project pumps (pump models which begin with
“PJ” or “PM”) may differ from the Operating and Installation Instruc-
tions.
➔For project pumps, also observe the agreed upon specifica-
tions.
1.2. Symbols and markings
Warning
WARNING
A danger is located here.
Possible consequences of a failure to observe the
warning are specified here. The signal word, e.g.
Warning, indicates the danger level.
➔Measures for avoiding the danger and its conse-
quences are specified here.
Danger levels
Signal word
Meaning
Consequences if not observed
DANGER
warns of immedi-
ate danger
Death or serious injuries and/or
serious damage are the conse-
quence.
WARNING
warns of possible
danger
Death or serious injuries and/or
serious damage are possible.
CAUTION
warns of a possi-
bly dangerous
situation
Minor injuries or damage are
possible.
Tab. 1
Other information and symbols
➔An activity to be carried out (a step) is specified here.
1. The first step of an activity to be carried out is specified here.
Additional, consecutively numbered steps follow.
This symbol refers to important information.
Project pump

Use Vacuum Pumps N 920 APE-W and N 920 APDC-B
4 Translation of original Operating and Installation Instructions, english, KNF 121690-121708 09/19
2. Use
2.1. Proper use
The pumps are exclusively intended for transferring gases and va-
pors.
Owner’s responsibility
Only install and operate the pumps under the operating parameters
and conditions described in Chapter 4. Technical Data.
Only complete pumps may be taken into service.
Make sure that the installation location is dry and the pump is pro-
tected against rain, splash, hose and drip water as well as other
pollutions.
The gas-tightness of the connections between the application
pipes and the pump (or the pump connection) must be checked
regularly; with leaky connections, there is a danger that hazardous
gases or vapors may escape from the pump system.
Before using a medium, check whether the medium can be trans-
ferred danger-free in the specific application case.
Before using a medium, check the compatibility of the materials of
the components in contact with the medium (see Chapter 4. Tech-
nical Data) with the medium.
Risk of hazardous gas mixtures during pump operation if dia-
phragm ruptures: Depending on the medium transferred, a hazard-
ous mixture may be produced in the case that the diaphragm rup-
tures, if the medium mixes with the air in the compressor housing.
Only transfer gases which remain stable under the pressures and
temperatures occurring in the pump.
Operating parameter and
conditions
Requirements for
transferred medium

Vacuum Pumps N 920 APE-W and N 920 APDC-B Use
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2.2. Improper use
The pumps may not be operated in an explosive atmosphere.
The pumps are not suitable for transferring:
▪dusts
▪liquids
▪aerosol
▪biological and microbiological substances
▪fuel
▪explosive and combustible materials
▪fibers
▪oxidizing agent
▪foodstuffs.
The pumps are not suitable for use with aggressive media. Other
pumps in the KNF product line are designed for use with aggres-
sive media. Please contact us for more information.
The pumps must not be used to create vacuum and overpressure
simultaneously.
An overpressure must not be applied to the suction side of the
pump.

Safety Vacuum Pumps N 920 APE-W and N 920 APDC-B
6 Translation of original Operating and Installation Instructions, english, KNF 121690-121708 09/19
3. Safety
Note the safety precautions in Chapter 7. Installation and con-
nection and 8. Operation.
The pumps are built according to the generally recognized rules of
the technology and in accordance with the occupational safety and
accident prevention regulations. Nevertheless, dangers can result
during their use which lead to injuries to the user or others, or to
damage to the pump or other property.
Only use the pumps when they are in a good technical and proper
working order, in accordance with their intended use, observing the
safety advice within the Operating and Installation Instructions, at
all times.
Components connected to the pump must be designed to with-
stand the pneumatic performance of the pump.
Take care that safety regulations are observed when connecting
the pump to the electricity supply.
Make sure that only trained and instructed personnel or specially
trained personnel work on the pumps. This especially applies to
assembly, connection and servicing work.
Make sure that the personnel has read and understood the Operat-
ing and Installation Instructions, and in particular the “Safety” chap-
ter.
Observe the accident prevention and safety regulations when per-
forming any work on the pump and during operation.
For pump N 920 APE-W: Open housing parts with notice sticker
(see Fig. 1) only after separating mains plug from power source.
Ensure that the pump is separated from the mains and is de-ener-
gized.
Make sure that there are no hazards due to flow with open gas
connections, noises or hot gases.
Ensure that an EMC-compatible installation of the pump is ensured
at all times and that this cannot lead to a hazardous situation.
When transferring dangerous media, observe the safety regula-
tions when handling these media.
If the diaphragm ruptures, the transferred medium will mix with the
air in the environment.
Take all necessary care to prevent this leading to a dangerous situ-
ation.
Be aware that the pumps are not designed to be explosion-proof.
Make sure the temperature of the medium is always sufficiently be-
low the ignition temperature of the medium, to avoid ignition or ex-
plosion. This also applies for unusual operational situations.
Note that the temperature of the medium increases when the pump
compresses the medium.
Personnel
Working in a safety
conscious manner
Fig. 1: notice sticker
Handling dangerous media
Handling combustible media

Vacuum Pumps N 920 APE-W and N 920 APDC-B Safety
Translation of original Operating and Installation Instructions, english, KNF 121690-121708 09/19 7
Hence, make sure the temperature of the medium is sufficiently be-
low the ignition temperature of the medium, even when it is com-
pressed to the maximum permissible operating pressure of the
pump. The maximum permissible operating pressure of the pump
is stated in the technical specifications (Chapter 4).
If necessary, consider any external sources of energy, such as ra-
diation, that may add heat to the medium.
In case of doubt, consult the KNF customer service.
Store all replacement parts in a protected manner and dispose of
them properly in accordance with the applicable environmental pro-
tection regulations. Observe the respective national and interna-
tional regulations. This especially applies to parts contaminated
with toxic substances.
For the purposes of the Machinery Directive 2006/42/EC, pumps
are “partly completed machinery”, and are therefore to be regarded
as not ready for use. Partly completed machinery may not be com-
missioned until such time as it has been determined that the ma-
chine in which the partly completed machinery is to be assembled
is in conformity with the provisions of the Machinery Directive
2006/42/EC. The following essential requirements of Annex I of Di-
rective 2006/42/EC (general principles) are applied and observed:
−General Principles No. 1
−No. 1.1.2. / 1.1.3. / 1.3.1. / 1.3.3. / 1.3.4. / 1.4.1. / 1.5.1.* /
1.5.2.* / 1.5.8. / 1.5.9. / 1.7.4. / 1.7.4.1. / 1.7.4.3.
−(*only for N 920 APE-W)
As these partly completed machinery are OEM-models the power
supplies and the equipment for disconnecting and switching-off the
partly completed machinery respectively have to be considered
when mounting as well as over-current and overload protective
gear.
In addition a protection against mechanical parts in motion and hot
parts, if existing, has to be provided when mounting.
The pumps conform to the Directive 2011/65/EU.
The following harmonized standards have been used:
N 920 APE-W
N 920 APDC-B
DIN EN 61326-1 (Class A)
DIN EN 61326-1 (Class A)
DIN EN 61000-6-2/3
DIN EN 50581
DIN EN 60204-1
DIN EN 50581
Tab. 2
Environmental protection
EU/EC Directives / Standards

Safety Vacuum Pumps N 920 APE-W and N 920 APDC-B
8 Translation of original Operating and Installation Instructions, english, KNF 121690-121708 09/19
The pump is maintenance-free. But KNF recommends, checking
the pump regularly with regard to conspicuous changes in noise
and vibrations.
Only have repairs to the pumps carried out by the KNF Customer
Service responsible.
Housing with voltage-caring parts may be opened by technical per-
sonnel only.
Use only genuine parts from KNF for servicing work.
Customer service and
repairs

Vacuum Pumps N 920 APE-W and N 920 APDC-B Technical Data
Translation of original Operating and Installation Instructions, english, KNF 121690-121708 09/19 9
4. Technical Data
Pump materials
Assembly
Material
Pump head
Aluminum
Diaphragm
EPDM
Valve
EPDM
Tab. 3
Pneumatic values
Parameter
Value
Max. permissible operating
pressure [bar g]
0.5
Ultimate vacuum [mbar abs.]
< 1.5
Delivery rate [l/min]*
21
Tab. 4 *Liters in standard state (1013 mbar)
Pneumatic Connections
Pump type
Value
Thread size
G 1/8
Tab. 5
Electrical data
N 920 APE-W
Parameter
Value
Automatic mains power adjust-
ment
100-240V
50/60 Hz
Max. operating current [A]
1.3
Power consumption pump [W]
120
Maximum permitted mains
voltage fluctuations
+/- 10%
Protection class Motor
IP 20
Tab. 6
The pump is supplied by a universal power supply with inte-
grated overload protection. It is protected against overheating
by a temperature sensor on the motor board and equipped with
overcurrent protection.
If one of these safety functions is triggered, the pump will be
shut down and must be manually reset, as follows:
➔Separate pump from electrical power supply
➔Remove the cause(s) of the fault before restarting.

Technical Data Vacuum Pumps N 920 APE-W and N 920 APDC-B
10 Translation of original Operating and Installation Instructions, english, KNF 121690-121708 09/19
N 920 APDC-B
Parameter
Value
Motor type
Brushless DC motor
Voltage [V]
24 V
Max. operating current [A]
4.2
(starting current, momentary
200 ms: 7A)
Power consumption pump [W]
100
Maximum permitted mains
voltage fluctuations
+/- 10%
Protection class Motor
IP 00
Tab. 7
The pump is supplied by a universal power supply with inte-
grated overload protection. It is protected against overheating
by a temperature sensor on the motor board and equipped with
overcurrent protection.
If one of these safety functions is triggered, the pump will be
shut down and must be manually reset, as follows:
➔Separate pump from electrical power supply
➔Remove the cause(s) of the fault before restarting.
Weight
Pump type
Value
N 920 APE-W
10.0 kg
N 920 APDC-B
8.5 kg
Tab. 8
Other parameters
Parameter
Value
Permissible ambient tempera-
ture
+ 10°C bis + 40°C
Permissible media tempera-
ture
+ 5°C bis + 40°C
Dimensions L x H x W [mm]:
N 920 APE-W
N 920 APDC-B
324 x 182 x 127
292 x 161 x 119
Maximum permissible ambient
relative humidity
80% for temperatures up to
31°C, decreasing linearly to
50% at 40°C.
Max. altitude of site:
[m above sea level]
2000
Tab. 9

Vacuum Pumps N 920 APE-W and N 920 APDC-B Design and function
Translation of original Operating and Installation Instructions, english, KNF 121690-121708 09/19 11
5. Design and function
Design N 920 APE-W
Fig. 2: Design N 920 APE-W
Design N 920 APDC-B
Fig. 3: Design N 920 APDC-B
1 Inlet (suction side)
2 Outlet (pressure side)
3 Potentiometer
(special design)
4 Power switch
1 Motor control electronics
2 Inlet (suction side)
3 Outlet (pressure side)

Design and function Vacuum Pumps N 920 APE-W and N 920 APDC-B
12 Translation of original Operating and Installation Instructions, english, KNF 121690-121708 09/19
Function Diaphragm Pump
Fig. 4: Pump head
Diaphragm pumps transfer, compress (depending on pump ver-
sion) and evacuate gases and vapors.
The elastic diaphragm (4) is moved up and down by the eccentric
(5) and the connection rod (6). In the downward stroke it aspirates
the gas to be transferred via the inlet valve (2). In the upward
stroke, the diaphragm presses the medium out of the pump head
via the outlet valve (1). The transfer chamber (3) is hermetically
separated from the pump drive (7) by the diaphragm.
Function diaphragm stabilization system
Fig. 5: Function diaphragm stabilization system
An additional diaphragm, the so-called stabilization diaphragm (3),
separates the underside of the working diaphragm from the “crank”
space of the pump (see Fig. 5). The space between the two dia-
phragms, called a vacuum chamber (2), is connected with the suc-
tion side of the pump via an balancing connection (1). This way,
the vacuum chamber has approximately the same pressure as the
working space of the diaphragm pump. The pressure difference
between the upper and underside of the diaphragm approaches
zero. The working diaphragm remains stable, independent of the
inlet pressure of the pump. This improves the suction speed of the
pump significantly, over its entire working range.
1 Outlet valve
2 Inlet valve
3 Transfer chamber
4 Diaphragm
5 Eccentric
6 Connection rod
7 Pump drive
1 Balancing connection for
vacuum chamber
2 Vacuum chamber
3 Stabilization diaphragm

Vacuum Pumps N 920 APE-W and N 920 APDC-B Transportation
Translation of original Operating and Installation Instructions, english, KNF 121690-121708 09/19 13
6. Transportation
CAUTION
Physical injury and/or property damage due to incor-
rect or improper transport of the pump.
Incorrect or improper transport may cause the pump
to fall, be damaged or injure persons.
➔If necessary, use suitable aids (carrying strap,
lifting device, etc.).
➔If necessary, wear suitable personal protective
equipment (e.g. safety shoes, safety gloves).
CAUTION
Risk of injury due to sharp edges on the packaging
There is a possibility of injury by cutting on the sharp
edges while gripping on edges or when opening the
packaging.
➔If necessary, wear suitable personal protective
equipment (e.g. safety shoes, safety gloves).
➔Transport the pump in its original packaging to the installation
location.
➔Store the original packaging of the pump (for example, for fu-
ture storage).
➔Check the pump for transport damage upon receipt.
➔Document damage that has occurred during transport in writ-
ing.
➔If necessary, remove the transport safety devices before com-
missioning the pump.
Parameter
Parameter
Value
Storage temperature
+ 5°C to + 40°C
Transport temperature
- 10°C to + 60°C
Permiss. Humidity (non-con-
densing)
30% to 85%
Tab. 10

Installation and connection Vacuum Pumps N 920 APE-W and N 920 APDC-B
14 Translation of original Operating and Installation Instructions, english, KNF 121690-121708 09/19
7. Installation and connection
Only install and operate the pumps under the pneumatic operating
parameters and conditions described in Chapter 4, Technical Data.
Observe the safety precautions (see Chapter 3).
7.1. Installation of the pump
➔Choose a safe location (flat surface) for the pump.
➔Before installation, store the pump at the installation location to
bring it up to ambient temperature.
➔See Fig. 6 (N 920 APE-W) and Fig. 7 (N 920 APDC-B) for
mounting dimensions.
Fig. 6: Mounting dimensions pump series N 920 APE-W (All dimensional
tolerances conform to DIN ISO 2768-1, Tolerance Class V)
Mounting dimensions

Vacuum Pumps N 920 APE-W and N 920 APDC-B Installation and connection
Translation of original Operating and Installation Instructions, english, KNF 121690-121708 09/19 15
Fig. 7: Mounting dimensions pump series N 920 APDC-B (All dimensional
tolerances conform to DIN ISO 2768-1, Tolerance Class V)
WARNING
Danger of burns from hot surfaces
Hot surfaces may be caused by overheating of the
pump.
➔Install the pump so that the motor fan can intake
sufficient cooling air.
➔Make sure that the installation location is dry and the pump is
protected against rain, splash, hose and drip water as well as
other pollutions.
➔Make sure, that the installation location is accessible for
maintenance and service.
The IP protection class of the pump motor is indicated on the
type plate.
➔Install the pump at the highest point in the system to prevent
condensate from collecting in the pump head.
➔Protect the pump from dust.
➔Protect the pump from vibrations and jolts.
WARNING
Personal injury and/or damage to property because
of vibration
In conjunction with adjacent components, vibration of
the pump may result in crushing and/or damage to
these components.
➔Make sure that vibrations of the pump do not re-
sult in hazards associated with adjacent compo-
nents.
Cooling air supply
Installation location

Installation and connection Vacuum Pumps N 920 APE-W and N 920 APDC-B
16 Translation of original Operating and Installation Instructions, english, KNF 121690-121708 09/19
For pump N 920 APDC-B:
WARNING
Hazard of injuries during operation
➔Take protective measures against touching parts
connected to electrical power (electrical connec-
tion).
➔Take protective measures against touching mov-
ing parts (e.g. fans).
Hazard of damage to the pump during operation
➔Take protective measures against foreign ob-
jects which could enter the pump.
Protection against touching and
foreign objects

Vacuum Pumps N 920 APE-W and N 920 APDC-B Installation and connection
Translation of original Operating and Installation Instructions, english, KNF 121690-121708 09/19 17
7.2. Electrical connection
N 920 APE-W
1. Compare the supply data with the data on the motor-plate.
2. Insert the power cable’s plug into a properly installed shock-
proof socket.
N 920 APDC-B
DANGER
Extreme danger from electrical shock
➔Only have the pump connected by an authorized
specialist.
➔Only have the pump connected when the power
supply is disconnected.
➔When connecting the device to a power source, the relevant
standards, directives, regulations, and technical standards
must be observed.
➔In the electrical installation, arrangements (complying with
EN 60335-1) must be made for disconnecting the pump motor
from the electrical supply.
➔The motors of the pump must be protected according to
EN 60204-1 (protection against excess current, or overload-
ing).
For max. operating current of the pump see pump’s type plate.
➔It is recommended that an additional “Emergency Stop” switch
is installed.
➔The pump must be installed so that contact with live parts is
impossible.
➔Fasten the connection cables so that:
▪the cables do not contact moving or hot parts.
▪the cables will not chafe or be damaged on sharp edges or
corners.
▪no pulling or pushing forces are exerted on the cable’s
connection points (strain relief).
Attach connection cables

Installation and connection Vacuum Pumps N 920 APE-W and N 920 APDC-B
18 Translation of original Operating and Installation Instructions, english, KNF 121690-121708 09/19
Connecting pump
1. Compare the supply data with the data on the motor plate. For
maximum operating current of the pump see pump’s type
plate.
2. Connect the positive and negative pole.
Note the proper polarity:
red connection cable: +
black connection cable: -
Incorrect lead connection will damage electronics of brushless
DC motors (type designation ending with B). The supply wires
have inverse-polarity protection on the motor board for this pur-
pose, while the control-voltage wires do not have this protec-
tion function.
Control voltage may only be applied if the motor controller is
supplied with operating voltage. Otherwise damages can occur
on the motor controller.

Vacuum Pumps N 920 APE-W and N 920 APDC-B Installation and connection
Translation of original Operating and Installation Instructions, english, KNF 121690-121708 09/19 19
7.3. Pneumatic connection
CAUTION
Personal injury or damages to property by ejected
protective plugs
If the protective plug at the pressure side of the
pump hasn’t been removed, it could be ejected be-
cause of the overpressure during operation.
➔Remove the protective plug during the installa-
tion.
➔Only connect components to the pump which are designed for
the pneumatic data of the pump (see Chapter 4, Technical
Data).
➔If the pump s used as a vacuum pump, safely discharge the
pump exhaust at the pump’s pneumatic outlet.
➔KNF recommends mechanically disengaging the pump from
the piping system. This can be achieved with flexible tubing or
pipes, for example. This will avoid transferring to the system
any pump oscillations that may arise.
Connecting pump
A marking on the pump head shows the direction of flow.
CAUTION
Risk of injury due to mixing up suction and pressure
side
Confusion between suction and pressure sides can
lead to breakage of connected components on the
suction and pressure sides.
➔Observe the marking of the inlet/outlet.
1. Remove the protective plugs from the hose connection
threads.
2. The accessories silencer, filter, and hose connectors (where
applicable) are screwed into the port threads.
The filter or silencer is to be mounted on the suction side or
pressure side of the pump head. With multiple-head pumps,
this relates to the first pump head or last pump head.
3. Connect the suction line and pressure line (see Chapter 4,
Tab. 9 for mounting dimensions).
4. Lay the suction and pressure line at a downward angle to pre-
vent condensate from running into the pump.
Connected
components
Pump exhaust
Disengaging

Operation Vacuum Pumps N 920 APE-W and N 920 APDC-B
20 Translation of original Operating and Installation Instructions, english, KNF 121690-121708 09/19
8. Operation
8.1. General
WARNING
Danger of burns from hot pump parts or hot medium
During or after operation of the pump, some pump
parts may be hot.
➔Allow the pump to cool after operation.
➔Take safety precautions against the contact of
hot parts/media.
WARNING
Injury of the eyes
During excessive approach to the inlet or outlet of
the pump, the eyes could be injured by the upcoming
vacuum or overpressure.
➔Don’t look into the pump’s inlet or outlet during
the operation.
➔Only operate the pumps under the operating parameters and
conditions described in Chapter 4. Technical Data.
➔Make sure the pumps are used properly (see Chapter 2.1).
➔Make sure the pumps are not used improperly (see Chapter
2.2).
➔Observe the safety precautions (see Chapter 3).
➔The pumps are intended for installation. Before putting them
into service it must be established that machinery or equipment
in which they are installed meets the relevant regulations.
WARNING
Hazard of the pump head bursting due to excessive
pressure increase
➔Do not exceed max. permissible operating pres-
sure (see Chapter 4. Technical Data.
➔Monitor pressure during operation.
➔If the pressure exceeds the maximum permissi-
ble operating pressure, immediately switch off
pump and eliminate fault (see Chapter 10. Trou-
bleshooting).
➔Only throttle or regulate the air or gas quantity in
the suction line to prevent the maximum permis-
sible operating pressure from being exceeded.
➔If the air or gas quantity in the pressure line is
throttled or regulated, make sure that the maxi-
mum permissible operating pressure is not ex-
ceeded.
➔Ensure that the pump outlet is not closed or con-
stricted.