KNF UN 828 User manual

KNF 04/2022
OEM
UN 828 / UN 838
TRANSLATION OF ORIGINAL OPERATING AND
INSTALLATION INSTRUCTIONS
MINI DIAPHRAGM
VACUUM PUMPS
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 13
6. .... Installation and connection 18
7. ............................... Operation 32
8. ................................ Servicing 39
9. ..................... Troubleshooting 51
10.Spare parts and accessories 54
11. ................................ Returns 55
KNF Inc
2 Black Forest Rd
Trenton, NJ 08691
Phone [phone]
http://www.knf.com/

Diaphragm Vacuum Pump N 828 / N 838 About this document
Original-Operating and Installation Instructions, English, KNF 121249-121517 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.
 Pass on the Operating and Installation Instructions to the next
owner.
Customer-specific project pumps (pump models which begin with
“PJ”, “PM”, “PU” or “MPU”) may differ from the Operating and In-
stallation Instructions.
 For project pumps, observe the agreed upon specifications.
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 Diaphragm Vacuum Pump N 828 / N 838
4 Translation of original Operating and Installation Instructions, English, KNF 121249-121517 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 pump head, diaphragm and valves with the medium.
Only transfer gases which remain stable under the pressures and
temperatures occurring in the pump.
Operating parameter and
conditions
Requirements for
transferred medium

Diaphragm Vacuum Pump N 828 / N 838 Use
Translation of original Operating and Installation Instructions, English, KNF 121249-121517 09/19 5
2.2. Improper use
The pumps may not be operated in an explosive atmosphere.
The pumps are not suitable for transferring dusts.
The pumps are not suitable for transferring liquids.
The pumps are not suitable for transferring aerosol.
The pumps are not suitable for transferring biological and microbio-
logical substances.
The pumps are not suitable for transferring fuel.
The pumps are not suitable for transferring explosive and combus-
tible materials.
The pumps are not suitable for transferring fibers.
The pumps are not suitable for transferring oxidizing agent.
The pumps are not suitable for transferring 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 Diaphragm Vacuum Pump N 828 / N 838
6 Translation of original Operating and Installation Instructions, English, KNF 121249-121517 09/19
3. Safety
Note the safety precautions in Chapter 6. Installation and con-
nection and 7. 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.
Ensure that the pump is separated from the mains and is de-ener-
gized.
The pump heads heat up during operation – avoid contact with
them.
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
Handling dangerous media
Handling combustible media

Diaphragm Vacuum Pump N 828 / N 838 Safety
Translation of original Operating and Installation Instructions, English, KNF 121249-121517 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.
For pumps with AC motor:
When the operation of the pump is interrupted by the thermal
switch, the pump will re-start automatically after cooling down.
Take all care necessary to prevent this leading to a dangerous situ-
ation.
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 pumps with AC motor)
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.
Thermal switch
Environmental protection
EU/EC Directives / Standards

Safety Diaphragm Vacuum Pump N 828 / N 838
8 Translation of original Operating and Installation Instructions, English, KNF 121249-121517 09/19
The pumps conform to the Directive 2011/65/EU.
The following harmonized standards have been used:
UN 828 _NI
UN 838 _NI
UN 838.1.2 KNI
UN 828 _NDC
UN 838 _NDC
UN 828 KNDC-B
UN 828 KN.29DC-B
UN 838 KNDC-B
UN 838 KN.29DC-B
UN 838.1.2 KNDC-B
UN 838.1.2 KN.29DC-B
DIN EN 55014-1/2 DIN EN 55014-1/2 DIN EN 61000-6-2/3
DIN EN 61000-3-2/3 DIN EN 60034-1 DIN EN 50581
DIN EN 60335-1 DIN EN 61000-6-1/2
DIN EN 50581 DIN EN 50581
Tab. 2
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

Diaphragm Vacuum Pump N 828 / N 838 Technical Data
Translation of original Operating and Installation Instructions, English, KNF 121249-121517 09/19 9
4. Technical Data
Pump material
Assembly UN 828 AN_
UN 838 AN_
UN 828 KN_
UN 838 KN_
UN 838.1.2 KNE
UN 838.1.2 KNDC-B
UN 838.1.2 KN.29DC-B
Pump head Aluminum PPS
Diaphragm EPDM EPDM
Valve FPM FPM
Tab. 3
Pneumatic Values
Pumps with AC motor
Parameter UN 828 ANI
UN 828 KNI
UN 838 ANI
UN 838 KNI
UN 838.1.2 KNI
Max. permissible operating pressure
[bar g / psig]
1.0 / 14.5 0.5 / 7.3 0.5 / 7.3
Ultimate vacuum
[mbar abs.]
100 100 90
Flow rate at atm. pressure [l/min]* 28 34 42
Tab. 4 *Liters in standard state (1013 mbar)
Pumps with DC motor
Parameter UN 828 ANDC
UN 828 KNDC
UN 838 ANDC
UN 838 KNDC
Max. permissible operating pressure [bar g / psig] 1.0 / 14.5 0.5 / 7.3
Ultimate vacuum
[mbar abs.]
100 100
Flow rate at atm. pressure [l/min]* 27 32
Tab. 5 *Liters in standard state (1013 mbar)
Pumps with brushless DC motor
Parameter UN 828 KNDC-B
UN 828 KN.29DC-B
UN 838 KNDC-B
UN 838 KN.29DC-B
UN 838.1.2 KNDC-B
UN 838.1.2 KN.29DC-B
Max. permissible op-
erating pressure [bar
g / psig]
1.0 / 14.5 0.5 / 7.3 0.5 / 7.3
Ultimate vacuum at
nominal speed
[mbar abs.]
100 100 100
Flow rate at atm.
Pressure and nomi-
nal speed [l/min]*
28 34 60
Flow rate at atm.
Pressure and 0.1V
control voltage (only
.29-version) [l/min]*
6 8.5 12
Tab. 6 *Liters in standard state (1013 mbar)
Pneumatic connections
Pump type Value

Technical Data Diaphragm Vacuum Pump N 828 / N 838
10 Translation of original Operating and Installation Instructions, English, KNF 121249-121517 09/19
UN 828 AN_ / UN 828 KN_
UN 838 AN_ / UN 838 KN_
UN 838.1.2 KNI
UN 838.1.2 KNDC-B /
UN 838.1.2 KN.29DC-B
Thread size G 1/8 or 1/8 NPT
Tab. 7
Electrical Parameter
Pumps with AC motor, Pumps with DC motor
Parameter Value
Voltage / Frequencies
See Label on Pump Max. operating current
Pump power consumption
Motor protection class:
UN 828 AN_ / UN 828 KN_ / UN 838 AN_ / UN 838 KN_ IP 00
Motor protection class:
UN 838.1.2 KNI IP 20
Maximum permissible mains voltage fluctuations ± 10%
Tab. 8
Pumps with brushless DC motor
Parameter UN 828 KNDC-B
UN 828 KN.29DC-B
UN 838 KNDC-B
UN 838 KN.29DC-B
UN 838.1.2 KNDC-B
UN 838.1.2 KN.29DC-B
Voltage [V] 24 24 24
Control voltage
(only .29 version)
[V]
0.1…5* 0.1…5* 0.1…5*
Max. operating
current [A]:
- for p > patm.
- for p < patm.
2.4
2.0
2.4
2.2
4.2
3.9
Starting current The starting current can be up to 50% above the maximum operating
current.
Starting ramp [ms] 800 800 800
Max. power con-
sumption of the
pump [W]:
- for p > patm.
- for p < patm.
57.6
48.0
57.6
52.8
100.8
93.6
Maximum permis-
sible mains volt-
age fluctuations
± 10% ± 10% ± 10%
Motor protection
class
IP 20 IP 20 IP 20
Overcurrent limita-
tion of the motor
electronics [A]
7.5 7.5 7.5
Tab. 9 *further control voltage versions on demand
For pumps with AC motor:
The pumps are fitted with a thermal switch to protect against
overloading.
Thermal switch

Diaphragm Vacuum Pump N 828 / N 838 Technical Data
Translation of original Operating and Installation Instructions, English, KNF 121249-121517 09/19 11
WARNING
Automatic starting can cause personal injury and
pump damage
When the operation of the pump is interrupted by the
thermal switch, the pump will restart automatically af-
ter cooling down.
 Take all necessary care to prevent this leading
to a dangerous situation.
For UN 828 KNDC-B, UN 828 KN.29DC-B, UN 838 KNDC-B,
UN 838 KN.29DC-B, UN 838.1.2 KNDC-B,
UN 838.1.2 KN.29 DC-B:
The pump is protected against overheating by a temperature
sensor on the motor board and equipped with overcurrent pro-
tection.
If one of these safety functions is triggered or if the maximum
blocking time of the rotor is exceeded due to a fault, the pump
will be shut down and must be manually reset, as follows:
 Separate pump from the mains.
 Remove the cause(s) of the fault before restarting.
Weight
Pump type Weight (kg / lbs)
UN 828 AN_ / UN 828 KN_ 2.2 / 4.8
UN 838 ANI / UN 838 KNI 2.6 / 5.7
UN 838.1.2 KNI 4.4 / 9.7
UN 838 ANDC / UN 838 KNDC 2.4 / 5.9
UN 828 KNDC-B /
UN 828 KN.29DC-B
2.0 / 4.4
UN 838 KNDC-B /
UN 838 KN.29DC-B
2.5 / 5.5
UN 838.1.2 KNDC-B /
UN 838.1.2 KN.29DC-B
3.0 / 6.6
Tab. 10

Technical Data Diaphragm Vacuum Pump N 828 / N 838
12 Translation of original Operating and Installation Instructions, English, KNF 121249-121517 09/19
Other Parameter
Parameter Value
Permissible ambient temperature
(°C / °F )
+ 5°C to + 40°C / + 41°F to + 104°F
Permissible media temperature
(°C / °F )
+ 5°C to + 40°C / + 41°F to + 104°F
Dimensions L x H x W [mm / in]:
UN 828 ANI
UN 828 KNI
UN 838 _NI
UN 838.1.2 KNI
UN 828 _NDC
UN 838 _NDC
UN 828 KNDC-B /
UN 828 KN.29DC-B
UN 838 KNDC-B /
UN 838 KN.29DC-B
UN 838.1.2 KNDC-B /
UN 838.1.2 KN.29DC-B
ca. 152 x 116 x 79 / 5.9 x 4.5 x 3.1
ca. 152 x 118 x 79 / 5.9 x 4.6 x 3.1
ca. 153 x 122 x 84 / 6.0 x 4.8 x 3.3
ca. 243 x 129 x 95 / 9.5 x 5.0 x 3.7
ca. 150 x 119 x 79 / 5.9 x 4.6 x 3.1
ca. 150 x 123 x 82 / 5.9 x 4.8 x 3.2
ca. 138 x 125 x 115 / 5.4 x 4.9 x 4.5
ca. 137 x 129 x 115 / 5.3 x 5.0 x 4.5
ca. 198 x 128 x 115 / 7.7 x 5.0 x 4.5
Maximum permissible ambient rel-
ative humidity
80% for temperatures up to 31°C / 87.8°F,
decreasing linearly to 50% at 40°C / 104°F.
Maximum altitude of installation
[m / ft above sea level].
**Contact KNF for operating above stated
limit**
2000 / 6561
Tab. 11

Diaphragm Vacuum Pump N 828 / N 838 Design and function
Translation of original Operating and Installation Instructions, English, KNF 121249-121517 09/19 13
5. Design and function
Design UN 828 _NI
Fig. 1: Design UN 828 _NI
Design UN 838 _NI
Fig. 2: Design UN 838 _NI
1 Outlet (pressure side)
2 Inlet (suction side)
3 Electrical connection
4 Motor
1 Outlet (pressure side)
2 Inlet (suction side)
3 Electrical connection
4 Motor

Design and function Diaphragm Vacuum Pump N 828 / N 838
14 Translation of original Operating and Installation Instructions, English, KNF 121249-121517 09/19
Design UN 838.1.2 KNI
Fig. 3: Design UN 838.1.2 KNI
Design UN 828 _NDC
Fig. 4: Design UN 828 _NDC
1 Pneumatic connection
2 Motor
3 Electrical connection
4 Outlet (pressure side)
5 Inlet (suction side)
1 Outlet (pressure side)
2 Inlet (suction side)
3 Motor

Diaphragm Vacuum Pump N 828 / N 838 Design and function
Translation of original Operating and Installation Instructions, English, KNF 121249-121517 09/19 15
Design UN 838 _NDC
Fig. 5: Design UN 838 _NDC
Design UN 828 KNDC-B and UN 828 KN.29DC-B
Fig. 6: Design UN 828 KNDC-B and UN 828 KN.29DC-B
1 Outlet (pressure side)
2 Inlet (suction side)
3 Motor
1 Outlet (pressure side)
2 Inlet (suction side)
3 Motor controller
4 Motor

Design and function Diaphragm Vacuum Pump N 828 / N 838
16 Translation of original Operating and Installation Instructions, English, KNF 121249-121517 09/19
Design UN 838 KNDC-B and UN 838 KN.29DC-B
Fig. 7: Design UN 838 KNDC-B and UN 838 KN.29DC-B
Design UN 838.1.2 KNDC-B and UN 838.1.2 KN.29DC-B
Fig. 8: Design UN 838.1.2 KNDC-B and UN 838.1.2 KN.29DC-B
1 Outlet (pressure side)
2 Inlet (suction side)
3 Motor controller
4 Motor
1 Outlet (pressure side)
2 Inlet (suction side)
3 Motor
4 Motor controller
5 Pneumatic connection

Diaphragm Vacuum Pump N 828 / N 838 Design and function
Translation of original Operating and Installation Instructions, English, KNF 121249-121517 09/19 17
Function Diaphragm Pump
Fig. 9: 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.
1 Outlet valve
2 Inlet valve
3 Transfer chamber
4 Diaphragm
5 Eccentric
6 Connection rod
7 Pump drive

Installation and connection Diaphragm Vacuum Pump N 828 / N 838
18 Translation of original Operating and Installation Instructions, English, KNF 121249-121517 09/19
6. 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).
6.1. 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.
 For mounting dimensions see:
Fig. 10 UN 828 _NI
Fig. 11 UN 838 _NI
Fig. 12 UN 838.1.2 KNI
Fig. 13 UN 828 _NDC
Fig. 14 UN 838 _NDC
Fig. 15 UN 828 KNDC-B and
UN 828 KN.29DC-B
Fig. 16 UN 838 KNDC-B and
UN 838 KN.29DC-B
Fig. 17 UN 838.1.2 KNDC-B and
UN 838.1.2 KN.29DC-B
Mounting dimensions

Diaphragm Vacuum Pump N 828 / N 838 Installation and connection
Translation of original Operating and Installation Instructions, English, KNF 121249-121517 09/19 19
Fig. 10: Mounting dimensions UN 828 _NI (All dimensional tolerances con-
form to DIN ISO 2768-1, Tolerance Class V)
*only N 828 KNE
Fig. 11: Mounting dimensions UN 838 _NI (All dimensional tolerances con-
form to DIN ISO 2768-1, Tolerance Class V)
1/8 NPT
1/8 NPT
G 1/8 or 1/8 NPT
G 1/8 or 1/8 NPT

Installation and connection Diaphragm Vacuum Pump N 828 / N 838
20 Translation of original Operating and Installation Instructions, English, KNF 121249-121517 09/19
Fig. 12: Mounting dimensions UN 838.1.2 KNE (All dimensional tolerances
conform to DIN ISO 2768-1, Tolerance Class V)
Fig. 13: Mounting dimensions UN 828 _NDC (All dimensional tolerances
conform to DIN ISO 2768-1, Tolerance Class V)
G 1/8 or
1/8 NPT
G 1/8 or
1/8 NPT
G 1/8 or 1/8 NPT
G 1/8 or 1/8 NPT