Kobold KEP-2 User manual

Operating Instructions
for
Thermal Mass Flow Meter for Gas
Model: KEP-2

KEP-2
page 2 KEP-2 K01/0124
We don’t accept warranty and liability claims neither upon this publication nor in
case of improper treatment of the described products.
The document may contain technical inaccuracies and typographical errors. The
content will be revised on a regular basis. These changes will be implemented in
later versions. The described products can be improved and changed at any time
without prior notice.
© Copyright
All rights reserved.
1. Contents
1.Contents ........................................................................................................ 2
2.Note .............................................................................................................. 4
3.Instrument Inspection .................................................................................... 4
4.Regulation Use ............................................................................................. 5
5.Safety Instructions ......................................................................................... 5
6.Operation ...................................................................................................... 6
7.Scaling Analogue Output Compressed Air ................................................. 7
8.Installation ..................................................................................................... 8
8.1Pipe/tube requirements ........................................................................ 8
8.2Inlet/outlet runs .................................................................................... 8
8.3Installation of KEP-2 ............................................................................ 9
8.4Display Head Position .......................................................................... 9
9.Flow measuring ranges ............................................................................... 10
9.1Flow for different gases...................................................................... 10
10.Electrical wiring ........................................................................................... 12
10.1Modbus, 4...20 mA, Pulse .................................................................. 12
11.Operation .................................................................................................... 13
11.1Initialization ........................................................................................ 14
11.2 Main menu ........................................................................................ 14
11.3Settings .............................................................................................. 15
12.Status/Error messages ................................................................................ 29
12.1Status messages ............................................................................... 29
12.2Error messages ................................................................................. 30
13.Maintenance ............................................................................................... 31
14.Cleaning of the sensor head ....................................................................... 31
15.Re-Calibration ............................................................................................. 32
16.Spare parts and repair ................................................................................ 32
17.Calibration ................................................................................................... 32
18.Warranty ..................................................................................................... 32
19.Technical Information .................................................................................. 33
20.Order Codes ............................................................................................... 33
21.Dimensions ................................................................................................. 33
22.Disposal ...................................................................................................... 34
23.EU Declaration of Conformance ................................................................. 35

KEP-2
KEP-2 K01/0124 page 3
Manufactured and sold by:
Kobold Messring GmbH
Nordring 22-24
D-65719 Hofheim
Tel.: [phone]
Fax: [phone]
E-Mail: [email protected]
Internet: www.kobold.com

KEP-2
page 4 KEP-2 K01/0124
2. Note
Please read these operating instructions before unpacking and putting the unit into
operation. Follow the instructions precisely as described herein.
The instruction manuals on our website www.kobold.com are always for currently
manufactured version of our products. Due to technical changes, the instruction
manuals available online may not always correspond to the product version you
have purchased. If you need an instruction manual that corresponds to the
purchased product version, you can request it from us free of charge by email
([email protected]) in PDF format, specifying the relevant invoice number and
serial number. If you wish, the operating instructions can also be sent to you by
post in paper form against an applicable postage fee.
Operating instructions, data sheet, approvals and further information via the QR
code on the device or via www.kobold.com
The devices are only to be used, maintained and serviced by persons familiar with
these operating instructions and in accordance with local regulations applying to
Health & Safety and prevention of accidents.
When used in machines, the measuring unit should be used only when the
machines fulfil the EC machinery directive.
3. Instrument Inspection
Instruments are inspected before shipping and sent out in perfect condition.
Should damage to a device be visible, we recommend a thorough inspection of the
delivery packaging. In case of damage, please inform your parcel service /
forwarding agent immediately, since they are responsible for damages during
transit.
Scope of delivery:
The standard delivery includes:
 Thermal Mass Flow Meter for Gas model: KEP-2

KEP-2
KEP-2 K01/0124 page 5
4. Regulation Use
Any use of the device, which exceeds the manufacturer’s specification, may
invalidate its warranty. Therefore, any resulting damage is not the responsibility of
the manufacturer. The user assumes all risk for such usage.
The KEP-2 consumption sensor is used for continuous flow measurements.
The KEP-2 consumption sensor is designed and constructed exclusively for the
intended purpose described here and may only be used accordingly.
The user must check whether the instrument is suitable for the selected application.
It must be ensured that the medium is compatible with the wetted parts. The
technical data listed in the data sheet are binding.
Improper handling or operation outside the technical specifications is not permitted.
Claims of any kind based on improper use are excluded.
5. Safety Instructions
Please read carefully before starting the device!
Warning: Do not exceed the pressure range of 16 bar!
Observe the measuring range of the sensor!
Always observe the direction of flow when positioning the sensor!
The screwed fixture must be pressure tight.
It is absolutely necessary to avoid condensation on the sensor element or water
drops in the measuring air as they may cause faulty measuring results.
The manufacturer cannot be held liable for any damage which occurs as a result
of non-observance or non-compliance with these instructions. Should the device
be tampered with in any manner other than a procedure which is described and
specified in the manual, the warranty is cancelled and the manufacturer is exempt
from liability.
The device is destined exclusively for the described application.
We offer no guarantee for the suitability for any other purpose and are not liable for
errors which may have slipped into this operation manual. We are also not liable
for consequential damage resulting from the delivery, capability or use of this
device.
We offer you to take back the instruments of the instrument’s family KEP-2 which
you would like to dispose of.
The installation has to be carried out by authorized professionals.
Qualified employees from the measurement and control technology branch should
only carry out adjustments and calibrations

KEP-2
page 6 KEP-2 K01/0124
Caution! Danger of burns when touching surfaces!
During operation, the components, measuring section and connection nut, can
reach a temperature close to the process temperature.
To avoid burns, protection against contact must be ensured at elevated process
temperatures, as there is a risk of medium to light injury.
The consumption sensor KEP-2 works according to the calorimetric measuring
procedure.
Flammable gases
If this consumption sensor is used for measurement of flammable gases (e. g.
natural gas and so on)
we expressly would like to point out that the sensor has no
DVGW admission, however, it can be used
for measurements in natural gas. A
DVGW admission is not mandatory.
The consumption sensor corresponds with the current state of technology and
basically it can be used in any flammable and non-flammable gases.
The area outside the pipeline (ambient area of the sensor) must not be an explosive
area.
6. Operation
The KEP-2 is a compact consumption counter for compressed air and gases.
Special features:
- Optimum accuracy due to compact design
- Integrated Display showing Flow, consumption, velocity and temperature
- Input inner tube diameter via display keys
- Units free selectable. m³/h, m³/min, l/min, l/s, kg/h, kg/min, kg/s, cfm
- Modbus RTU (RS485) Interface
- Analogoutput 4...20mA
- Pulse output galv. isolated.
Service Software
- Analogue output 4...20 mA scaleable
- Selection of gas type (Air, Nitrogen, Argon, Nitrous oxide, CO2, Oxygen, Natural
gas)
- Read out Service data
- Sensor diagnoses

KEP-2
KEP-2 K01/0124 page 7
7. Scaling Analogue Output Compressed Air
Reference DIN1945/ ISO 1217: 20°C, 1000 mbar (Reference during calibration)
Description
V
ersion Analo
g
ue output
KEP-2 with integrated 1/4" meas. section
Low Speed
4…20 mA =
0…25 l/min
Standard 0…50 l/min
Max 0…105 l/min
Hi
g
h Speed 0…130 l/min
KEP-2 with integrated 1/2" meas. section
Low Speed
4…20 mA =
0...20 m³/h
Standard 0...45 m³/h
Max 0...90 m³/h
Hi
g
h Speed 0...110 m³/h
KEP-2 with integrated 3/4" meas. section
Low Speed
4…20 mA =
0...45 m³/h
Standard 0...85 m³/h
Max 0...175 m³/h
Hi
g
h Speed 0...215 m³/h
KEP-2 with integrated 1" meas. section
Low Speed
4…20 mA =
0...75 m³/h
Standard 0...145 m³/h
Max 0...290 m³/h
Hi
g
h Speed 0...355 m³/h
KEP-2 with integrated 1 1/4" meas. section
Low Speed
4…20 mA =
0...140 m³/h
Standard 0...265 m³/h
Max 0...530 m³/h
Hi
g
h Speed 0...640 m³/h
KEP-2 with integrated 1 1/2" meas. section
Low Speed
4…20 mA =
0...195 m³/h
Standard 0...365 m³/h
Max 0...730 m³/h
Hi
g
h Speed 0...885 m³/h
KEP-2 with integrated 2" meas. section
Low Speed
4…20 mA =
0...320 m³/h
Standard 0...600 m³/h
Max 0…1195m³/h
Hi
g
h Speed 0...1450 m³/h
KEP-2 with integrated 2 1/2" meas. section
Low Speed
4…20 mA =
0...550 m³/h
Standard 0...1025 m³/h
Max 0…2050m³/h
Hi
g
h Speed 0...2480 m³/h
KEP-2 with integrated 3" meas. section
Low Speed
4…20 mA =
0...765 m³/h
Standard 0...1420 m³/h
Max 0…2840m³/h
Hi
g
h Speed 0...3440 m³/h

KEP-2
page 8 KEP-2 K01/0124
8. Installation
8.1 Pipe/tube requirements
 Correctly sized gaskets
 Correct aligned flanges and gaskets
 Diameter mismatch at the pipe junctions should be avoided but must be less
than 1 mm. For further information see ISO 14511
 Ensure clean pipes after installation
8.2 Inlet/outlet runs
The principle of thermal Mass flow measurement is very sensitive against
disturbances. Therefore, it is necessary to ensure the recommended inlet and
outlet runs.
Table of additionally required inlet sections
Flow obstruction in front of the measuring
section
Minimum length
inlet
section (L1)
Minimum length
outlet section (L2)
Slight curve
(bend < 90°) 12 x D 5 x D
Reduction
(Pipe narrows to the meas. section) 15 x D 5 x D
Expansion
(Pipe expands towards meas. section) 15 x D 5 x D
90° bend
or T-piece 15 x D 5 x D
2 bends á 90°
on one level
20 x D 5 x D
2 bends á 90°
3-dimensional change of direction
35 x D 5 x D
Shut-off valve 45 x D 5 x D
15 x D 5 x D 15 x D 5xD 15 x D 5 x D
20 x D 5 x D 35 x D 5xD 45 x D 5 x D

KEP-2
KEP-2 K01/0124 page 9
The respective minimum values required are indicated here. If it is not possible to
observe the stipulated equalizing sections, considerable deviations in the
measuring results must be expected.
Attention:
The dimensions of the KEP-2 consumption counter measuring sections do not fulfil
the required minimum lengths of the input and outlet runs.
Please ensure recommended in - and outlet distances, dimensions for measuring
sections see page 12 and 13.
8.3 Installation of KEP-2
The sensor KEP-2 is pre-supplied with the measuring section.
 An installation at customer site is only allowed in the unpressurized state
of the system
 It has to be checked whether the KEP-2 is correctly installed in the
measuring section, the flow direction arrows must point in the same
direction.
 The connecting nut is tightened to a torque of 25 -30 Nm.
 Tightness of the connection must be checked and ensured
8.4 Display Head Position
The Position of the Display head is twistable by
180 e.g. in case of reverse flow direction.
For this purpose, the 6 fastening screws are to be
released and the display head rotated 180°.
Caution:
It must be ensured that the connection plugs are
still plugged and the gasket is installed correctly.

KEP-2
page 10 KEP-2 K01/0124
9. Flow measuring ranges
9.1 Flow for different gases
1/4" 3/8" 1/2“ 3/4" 1" 1 ¼" 1 ½" 2" 2 ½" 3"
Analog
output
20mA
Analog
output
20mA
Analog
output
20mA
Analog
output
20mA
Analog
output
20mA
Analog
output
20mA
Analog
output
20mA
Analog
output
20mA
Analog
output
20mA
Analog
output
20mA
l/min [m³/h]
**l/min
[m³/h] [m³/h] [m³/h] [m³/h] [m³/h] [m³/h] [m³/h] [m³/h]
Reference DIN1945/ ISO 1217: 20°C, 1000 mbar (Reference during calibration)
Air
Low Speed 25 225** 20 45 75 140 195 320 550 765
Standard 50 25 45 85 145 265 365 600 1025 1420
Max 105 50 90 175 290 530 730 1195 2050 2840
High Speed 130 60 110 215 355 640 885 1450 2480 3440
Adjustment to DIN 1343: 0°C, 1013,25 mbar
Air
Low Speed 25 200** 20 40 70 130 180 295 505 705
Standard 50 380** 40 80 135 240 335 550 945 1305
Max 100 45 80 160 270 485 670 1100 1885 2610
High Speed 120 55 100 195 325 590 815 1330 2280 3165
Argon (Ar)
Low Speed 45 20 35 75 120 220 305 505 865 1200
Standard 85 35 70 135 230 415 570 935 1605 2225
Max 170 75 140 275 460 830 1140 1870 3205 4440
High Speed 205 95 170 335 555 1005 1385 2265 3880 5380
Carbon dioxide
(CO2)
Low Speed 25 225** 20 45 75 140 195 320 545 760
Standard 50 25 45 85 145 260 360 590 1015 1405
Max 105 50 90 175 290 525 720 1185 2030 2810
High Speed 130 60 105 210 350 635 875 1430 2455 3405
Nitrogen (N2)
Low Speed 25 205** 20 40 70 130 180 295 505 705
Standard 50 20 40 80 135 240 335 550 945 1305
Max 100 45 80 160 270 485 670 1100 1885 2610
High Speed 120 55 100 195 325 590 815 1330 2280 3165
Oxygen (O2)
Low Speed 25 215** 20 45 75 135 185 305 525 730
Standard 50 20 40 80 140 250 345 570 980 1355
Max 100 45 85 165 280 505 695 1140 1955 2710
High Speed 125 55 105 205 340 610 845 1380 2365 3280
Nitrous oxide
(N2O)
Low Speed 25 220** 20 45 75 140 190 315 540 750
Standard 50 20 40 85 140 260 355 585 1005 1395
Max 105 45 85 170 285 520 715 1170 2010 2785
High Speed 125 60 105 210 345 630 865 1420 2435 3375
Natural gas
(NG)
Low Speed 15 130** 15 25 45 85 115 190 325 450
Standard 30 245** 25 50 85 155 215 355 605 840
Max 60 25 50 105 170 310 430 705 1210 1680
High Speed 75 35 65 125 210 380 520 855 1465 2035
Other gases on request

KEP-2
KEP-2 K01/0124 page 11
Please note:
The consumption sensor corresponds with the current state of technology and
basically it can be used in any flammable and non-flammable gases.
If this consumption sensor is used for measurement of flammable gases (e.g.
natural gas and so on) we expressly would like to point out that the sensor has no
DVGW admission, however, it can be used for measurements in natural gas. A
DVGW admission is not mandatory.
The area outside the pipeline (ambient area of the sensor) must not be an explosive
area.

KEP-2
page 12 KEP-2 K01/0124
10. Electrical wiring
10.1 Modbus, 4...20 mA, Pulse
Attention: Not required connections NC must not be connected to a voltage
and/or to protection earth. Cut and insulate cables.
Pin 1 Pin 2 Pin 3 Pin 4 Pin 5
Connector plug A +VB RS 485 (A)
RS 485 (+) -VB RS 485 (B) RS 485 (-) I+
4...20 mA
Connector plug B
Pulse output (standard)
NC GND DIR Pulse
galv. isolated
Pulse
galv. isolated
Connector plug B
Option MBus NC GND DIR MBus MBus
Colours pulse cables
0553 0106 (5 m)
0553.0107 (10 m)
brown white blue black grey
Legend:
-VB Negative supply voltage 0 V
+VB Positive supply voltage 18...36 VDC
smoothed
I + Current signal 4...20 mA – selected measured
RS 485 (A)
RS 485 (B)
Modbus RTU A / Modbus RTU (+)
Modbus RTU B / Modbus RTU (-)
Pulse Pulse for consumption
NC Must not be connected to a voltage and/or to
protection earth. Please cut and isolate cables.
MBus MBus (reverse polarity protected)
If no connection cable/ pulse cable is ordered the sensor will be supplied with a
M12 connector plug. The user can connect the supply and signal cables as
indicated in the connection diagram.

KEP-2
KEP-2 K01/0124 page 13
M12 Connector plug
View from back side
(terminal side)
Connector plug A (M12 - A-coding) Connector plug B (M12 - A-coding)
Remark: If the sensor is placed at the end of the Modbus system a
termination is required. The sensors have an internal switchable termination,
therefore the 6 fastening screws from the lid are to be released and set the
internal DIP Switch to “On”. It must be ensured that the connection plugs are
still plugged and the gasket is installed correctly.
Alternatively, a 120R resistor can be installed in the plug between pin 2 and
pin 4.
11. Operation
Remark: Only for version with display
The operation of the KEP-2 is done by the two capacitive key buttons Up () und
Enter (
 ).

KEP-2
page 14 KEP-2 K01/0124
11.1 Initialization
After switching on the KEP-2, the initialized
screen is displayed followed by the main menu.
11.2 Main menu
Switching to pages 2-4 or back by pressing key „“
AV-Time (Period for average value calculation) could be changed under Sensor
Setup.-Advanced– AV- Time

KEP-2
KEP-2 K01/0124 page 15
11.3 Settings
The settings menu could accessed by pressing the key „OK“. But the access to
the settings menu is password protected.
11.3.1 Sensor Setup
Setup →Sensor Setup

KEP-2
page 16 KEP-2 K01/0124
11.3.1.1 Input / change tube diameter
Settings→Sensor Setup→Diameter
For KEP-2 not adjustable (suspended) as voted on included measuring section with
corresponding pipe diameter.
11.3.1.2 Input / change consumption counter
Setup →Sensor Setup→Total Counter →Unit button
Important!
When the counter reach 100000000 m³ the counter will be reset to zero.
11.3.1.3 Definition of the units for flow, velocity, temperature and pressure
Setup →Sensor Setup→Units

KEP-2
KEP-2 K01/0124 page 17
11.3.1.4 Definition of the reference conditions
Here can be defined the desired measured media reference conditions for pressure
and temperature and times for the filter and averaging.
 Factory presetting for reference temperature and reference pressure are 20 °C,
1000 hPa
 All volume flow values (m³/h) and consumption values indicated in the display
are related to 20 °C and 1000 hPa (according to ISO 1217 intake condition)
 Alternatively, 0 °C and 1013 hPa (=standard cubic meter) can also be entered
as a reference.
 Do not enter the operation pressure or the operation temperature under
reference conditions!
Setup →Sensor Setup→Advanced
 Setup →Sensor Setup →Advanced →Ref.Pref
Setup →Sensor Setup→Advanced →Ref.Temp

KEP-2
page 18 KEP-2 K01/0124
Setup →Sensor Setup→Advanced →Filtertime
Setup →Sensor Setup→Advanced →AV-Time
11.3.1.5 Setting of Zeropoint and Low-flow cut off
Setup →Sensor Setup→ZP Adjust

KEP-2
KEP-2 K01/0124 page 19
Setup →Sensor Setup →ZP Adjust →ZeroPnt
Setup → Sensor Setup → ZP Adjust →CutOff
Setup →Sensor Setup →ZP Adjust t →Reset

KEP-2
page 20 KEP-2 K01/0124
11.3.2 Modbus Settings
11.3.2.1 Modbus RTU Setup
The Flow sensors KEP-2 comes with a Modbus RTU Interface. Before commissioning the
sensor, the communication parameters
 Modbus ID, Baudrate, Parity und Stop bit
must be set in order to ensure the communication with the Modbus master.
Settings → Modbus Setup
Default values out of factory:
Modbus ID: 1
Baud rate: 19200
Stopbit: 1
Parity: even
Byte Order: ABCD