Seikom Electronic F3.xEx Series User manual

SEIKOM-Electronic GmbH & Co. KG –Fortunastr. 20 –42489 Wülfrath –Germany
Phone: [phone] / 20 44 –www.seikom-electronic.de –Email: [e-mail]
Air Flow Monitoring
Operating Instructions for the Air Flow
Sensors and Monitors of Series F3.xEx and
NLSW75-AEx (St)
The person installing the devices as well as the system operator are obligated to ensure the satisfaction of the
mandatory national ex-legislation. Electrostatic charges on plastic parts and wires must be avoided. The
devices must be protected from any damage. The wire connecting the flow sensor must be attached to
stationary surfaces and must be protected from any harm. Stray radiation must be avoided.
Our products satisfy the requirements specified in the European directives WEEE 2012/19/EU and
RoHS 2011/65/EU.

SEIKOM-Electronic GmbH & Co. KG –Fortunastr. 20 –42489 Wülfrath –Germany
Phone: [phone] / 20 44 –www.seikom-electronic.de –Email: [e-mail]
Table of Contents
1. Preamble................................................................................................................................................... 1
1.1 Safety Instructions............................................................................................................................. 1
2. General Information on Explosion Protection...................................................................................... 1
2.1 Electrical Specifications for Ex-i....................................................................................................... 2
2.2 Intrinsically Safe Parameters............................................................................................................. 2
2.3 Sensor Properties for Series F3.xEx.................................................................................................. 3
2.4 Type Code ......................................................................................................................................... 3
2.5 Dimensions of the Air Flow Sensors F3.xEx .................................................................................... 3
2.5.1 F3Ex .......................................................................................................................................... 3
2.5.2 F3.1Ex ....................................................................................................................................... 3
2.5.3 F3.2Ex ....................................................................................................................................... 4
2.5.4 F3.3Ex ....................................................................................................................................... 4
2.6 Temperature Class............................................................................................................................. 4
2.7 General Requirements ....................................................................................................................... 4
2.7.1 Intended Use.............................................................................................................................. 4
2.7.2 General Safety Instructions ....................................................................................................... 4
3. Installation and Start-Up........................................................................................................................ 5
3.1 Installation Conditions of the Air Flow Sensors F3.xEx................................................................... 6
3.2 Installation......................................................................................................................................... 6
4. Maintenance and Service........................................................................................................................ 7
4.1 Definitions......................................................................................................................................... 7
5. Troubleshooting....................................................................................................................................... 7
6. Disposal..................................................................................................................................................... 8
7. Labelling of the Air Flow Sensors F3.xEx............................................................................................. 8
8. General description NLSW75-AEx........................................................................................................ 8
9. Technical Data of the Air Flow Monitors NLSW75-AEx.................................................................... 9
10. Installation of the Air Flow Monitors NLSW75-AEx ...................................................................... 9
10.1 Start-Up and Switch-Point Adjustment........................................................................................... 10

Air Flow Monitoring
Operating Instructions for the Air Flow Sensors and Monitors of Series F3.xEx and NLSW75-AEx
SEIKOM-Electronic GmbH & Co. KG –Fortunastr. 20 –42489 Wülfrath –Germany
Phone: [phone] / 20 44 –www.seikom-electronic.de –Email: [e-mail] 1
1. Preamble
1.1 Safety Instructions
Please read the entire operating instructions to ensure the full operational capability of the devices and your
own safety before starting their installation. If questions arise you may contact the manufacturer SEIKOM-
Electronic GmbH & Co.KG directly. The directions, contained in these operating instructions, must be
followed.
The products were assessed according to the following standards:
a) IEC 60079-0:2017 Ed. 7 “Explosive atmospheres – Part 0: Equipment –General requirements”
b) IEC 60079-11:2011 Ed. 6 + Corr. 2012 / EN 60079-11:2012 “Explosive atmospheres –Part 11:
Equipment protection by intrinsic safety “i” “
c) TRGS 727:2016 “Vermeidung von Zündgefahren infolge elektrostatischer Aufladung“
2. General Information on Explosion Protection
The intrinsically safe air flow sensor measures flow velocities in the range of 0.1…20 m/s via the
calorimetric principle. According to the operating principle either the degree of cooling (cooling method) or
the required amount of heat, necessary to maintain the heating sensor elements’ temperature constant
(constant temperature method), is determined to indicate flow.
The air flow sensors of the series F3.xEx are built for commercial use and shall only be used according to the
technical documentation provided by SEIKOM-Electronic GmbH & Co.KG and specifications on their
labels. The air flow sensors shall only be operated with certified products via an intrinsically safe electrical
circuit, which is fed by Zener-barriers. These barriers satisfy valid standards and provisions.
The general provisions on the construction of facilities in areas exposed to explosion hazards (e.g. EN
60079-14) need to be considered.
More important details can be found in the alongside delivered EC type examination certificate.
The requirements regarding simple electrical utilities applicable within areas exposed to explosion hazards
due to gases in zone 1 according to EN 60079-11 are satisfied.
In accordance with its label, the air flow sensor can be used as specified below:
In zone 2 (Gas-Ex, EPL Gc) in ex-groups IIA, IIB and IIC.
The qualification concerning the surface temperature is T4. The equipment does not present an ignition
source for any gases, vapours and fogs with an ignition temperature above 135 °C.
The permissible ambient temperature range for the air flow sensor is -10 °C ≤ Ta ≤ 50 °C. The permissible
ambient temperature range for the NLSW75-AEx is -20 °C ≤ Ta ≤ 50 °C. The permissible media temperature
(air flow sensor) is 0 °C ≤ T ≤ 60 °C.
Self-heating is generally negligible, in case of failure the threshold values of temperature class T4 may be
reached.

Air Flow Monitoring
Operating Instructions for the Air Flow Sensors and Monitors of Series F3.xEx and NLSW75-AEx
SEIKOM-Electronic GmbH & Co. KG –Fortunastr. 20 –42489 Wülfrath –Germany
Phone: [phone] / 20 44 –www.seikom-electronic.de –Email: [e-mail] 2
2.1 Electrical Specifications for Ex-i
2.2 Intrinsically Safe Parameters
Type
Value
Ui
25 VDC
Ii
80 mA
Pi
0,35 W @ 40 °C
0,24 W @ 110 °C
Ci
negligible
Li
negligible

Air Flow Monitoring
Operating Instructions for the Air Flow Sensors and Monitors of Series F3.xEx and NLSW75-AEx
SEIKOM-Electronic GmbH & Co. KG –Fortunastr. 20 –42489 Wülfrath –Germany
Phone: [phone] / 20 44 –www.seikom-electronic.de –Email: [e-mail] 3
2.3 Sensor Properties for Series F3.xEx
Type
F3Ex
F3.1Ex
F3.2Ex
F3.3Ex
Article-No
50276/ex
50276/130/Ex
50276/150/Ex
50276/300/Ex
Approx. immersion depth
50 mm
130 mm
165 mm
300 mm
Permissible
media temperature
0 °C ... +60 °C
Permissible
ambient temperature
-10 °C ... +50 °C
Temperature gradient
10 K/min
Connection
PG 7
Sensor tube material
CuZn39Pb2, nickel plated
Compression strength
10 bar
Electrical connection
2,5 m / 3 x 0.75 mm2
Protection class
IP67
Evaluation unit
NLSW45-3Ex, NLSW75AEx
Wire colors
Black numbered
Tested according to DIN EN 61010-1:2011-07 by TÜV-Nord
2.4 Type Code
There is only one kind of flow sensor F3, the different types vary only by their length. Please review the
table shown above.
2.5 Dimensions of the Air Flow Sensors F3.xEx
2.5.1 F3Ex
2.5.2 F3.1Ex

Air Flow Monitoring
Operating Instructions for the Air Flow Sensors and Monitors of Series F3.xEx and NLSW75-AEx
SEIKOM-Electronic GmbH & Co. KG –Fortunastr. 20 –42489 Wülfrath –Germany
Phone: [phone] / 20 44 –www.seikom-electronic.de –Email: [e-mail] 4
2.5.3 F3.2Ex
2.5.4 F3.3Ex
The drawing will be available in the near future.
2.6 Temperature Class
The sensors are suitable for use with temperature class T4.
2.7 General Requirements
2.7.1 Intended Use
a) Safe use can only be ensured if the devices are used according to the specifications of the operating
instructions provided in this document. Moreover, the legal and safety requirements specific to the
individual use must be satisfied. This is also applicable to the use of additional equipment such as
accessories.
b) Incorrect use of the product or deviation from the directions contained by this instruction result in a
cancellation of our liability. Furthermore, any warranty on products or spare parts will be cancelled.
c) The products are no safety features in the scope of their dedicated use.
d) Only original parts from the manufacturer can be used.
2.7.2 General Safety Instructions
The sensor corresponds to the best available technology and is reliable in operation. If installed or operated
incorrectly, for instance due to installation or operation by unqualified personnel, a residual risk may arise
from the sensor.
Any person conducting the installation, start-up, maintenance or repair of the air flow sensors and monitors
must have read and understood the operating instructions and especially the safety instructions.
a) Consider general engineering rules and the dedicated use when choosing a product.
b) All electrical and mechanical equipment must be suitable for their intended use.
c) Pay attention to the information provided in this manual as well as the permissible operating
conditions printed on the label/type plate of the respective product.
d) Ensure that only products with the required ignition protection type, depending on the zone, are
installed!
e) The products are only approved for their designated and appropriate use in ordinary industrial
atmosphere. Immersion in liquids is impermissible.
f) Ensure that no falling objects may hit the product. In connection with rust (corrosion), light metal
and kinetic energy an exothermal, ignitable reaction can result.
g) The operator has to ensure the lightning protection according to local regulations.
h) Follow general engineering rules when choosing and operating products.

Air Flow Monitoring
Operating Instructions for the Air Flow Sensors and Monitors of Series F3.xEx and NLSW75-AEx
SEIKOM-Electronic GmbH & Co. KG –Fortunastr. 20 –42489 Wülfrath –Germany
Phone: [phone] / 20 44 –www.seikom-electronic.de –Email: [e-mail] 5
i) The person performing the installation of the air flow sensors and their connection to the flow
monitors is responsible for their correct function and must ensure that they are eligible for their
intended use.
j) The intrinsically safe connection, including the air flow sensors, must be carried out via approved
flow monitors, which, if necessary, must be installed with suitable Zener-barriers or switching
amplifiers.
3. Installation and Start-Up
Depending on the IP protection class time intervals for cleaning of the equipment (accumulation of dust)
must be set. Additional important facts:
a) The product can be installed in zone 2 (Cat. 3G, EPL Gc) or in zone 1 (Cat. 2G, EPL Gb) in
intrinsically safe electrical circuits by professionals equally competent to qualified personnel
according to TRBS 1203.
b) The information provided on the label must be followed bindingly during installation.
c) The products can only be operated in ordinary industrial atmosphere. The manufacturer must be
contacted if the atmosphere contains aggressive components. In case of adverse ambient conditions,
the sensors need to be protected accordingly.
d) Usage of the devices is only permissible when they are fully mounted and connected in an intact
condition. Damages would enable a zone entrainment which must therefore be considered by the
operator. Usage of devices with damaged casing is not permitted.
e) The in this operating instructions defined permissible ambient conditions must be met, the products
must be protected from adverse ambient conditions.
f) Thermal radiation of other components and products must be considered.
g) The air flow sensors must be protected from impermissible inflow of liquids and/or pollution.
h) Tight or stuck parts, e. g. due to frost or corrosion, cannot be loosened with force if exposed to an
explosive atmosphere. Icing must therefore be avoided.
i) The air flow sensors can only be exposed to minor vibrations, see IEC 34-14.
j) To ensure the dissipation of electrostatic charges, national regulations must be considered.
k) Especially capacities that build up in an isolated manner must be avoided.
l) The flow sensor housing should be connected to the potential equalization electrostatically, a
threshold value of 1MΩis permissible.
m) Only Zener-barriers and switching amplifiers with Ex-area approved output circuits can be used. In
Europe the use within zone 1 requires an EC type examination for the relevant equipment, issued by
a for explosion protection appointed authority.
n) The power P0of all supply units combined must be lower or equal to the power Piof the air flow
sensors.
o) The supply voltage of the supply units must be lower or equal to the voltage Uiof the air flow
sensors.
p) The current Ioof all supply units combined must be lower or equal to the current Iiof the air flow
sensors.
q) For the installation of an intrinsically safe electrical circuit, a block diagram (system description) is
necessary, which must be provided by the builder or operator.
r) If a Zener-barrier is used, a potential equalisation between the grounding connection and the flow
sensor casing alongside the intrinsically safe electrical circuit must be ensured
s) The certificates including the therein defined special conditions must be considered.
t) Tight or stuck parts, e. g. due to frost or corrosion, cannot be loosened with force if exposed to an
explosive atmosphere.
u) The flow sensors cannot be used in facilities with cathodic corrosion protection. Although special
precautions might enable the use of the flow sensors in this special case, the manufacturer must be
contacted in any scenario. Parasitic currents cannot be discharged via the construction.
v) Within the area exposed to an explosion hazard the installation must comply with local regulations.

Air Flow Monitoring
Operating Instructions for the Air Flow Sensors and Monitors of Series F3.xEx and NLSW75-AEx
SEIKOM-Electronic GmbH & Co. KG –Fortunastr. 20 –42489 Wülfrath –Germany
Phone: [phone] / 20 44 –www.seikom-electronic.de –Email: [e-mail] 6
The following conditions must be met:
a) Installation and maintenance may only be executed in atmospheres without any explosion hazard and
in compliance with the applicable national regulations depending on the location of operation.
b) Additional precautions must be made if hydrogen sulphide, ethylene oxide or carbon monoxide may
be or are present. These substances require only very low energy to ignite!
c) In case these substances and a substance of explosion group IIC and a presumably explosive
atmosphere are present only non-arcing tools can be used!
3.1 Installation Conditions of the Air Flow Sensors F3.xEx
Please consider the following points while mounting the air flow sensors to avoid any malfunction:
a) The tip of the sensor should be placed in the centre of the tube. The gaseous medium must fully flow
through the drilled hole located within the tip section of the sensor.
b) The mark on the base of the sensor may be used to verify whether the opening of the drilled hole
points in the direction of the flow.
c) In case of vertical tubing the direction of flow should be upwards.
d) An inlet zone of 5xD, before the sensor, and an outlet zone of 3xD, after the sensor should be
maintained (D=inner diameter of the pipe).
e) The air flow sensor must be connected with the air flow monitor according to the block diagram.
Any alteration of the connections leads to malfunction and may result in defects.
f) The shield must be connected to the potential equalisation.
g) An extension of the sensor wiring (shielded) is only permitted if the wiring is used in non-explosive
atmosphere. Yet, a total length of 30 m at a minimum cross section of 1,5 mm² cannot be exceeded.
During operation the following points concerning the wiring must be considered:
a) In case of flexible mounting the applicable temperature range is -5 °C up to +80 °C with a minimum
bend radius of 10x wire diameter.
b) In case of stationary mounting the applicable temperature range is -40 °C up to +80 °C with a
minimum bend radius of 10x wire diameter.
The wiring is not eligible for outdoor use or burying in the ground. Please contact the manufacturer if the
present operating conditions deviate from the specifications.
3.2 Installation
The sensor can be mounted via the PG7 connected to the sensor housing. Furthermore, mounting can be
supported by the alongside delivered PG7-nuts. During mounting the mark may be used to ensure the correct
orientation of the hole within the tip of the sensor, so that the medium can fully flow through it. During start-
up of the device with media temperatures below 0 °C and strong air flow, the start-up time may increase to
60 s.

Air Flow Monitoring
Operating Instructions for the Air Flow Sensors and Monitors of Series F3.xEx and NLSW75-AEx
SEIKOM-Electronic GmbH & Co. KG –Fortunastr. 20 –42489 Wülfrath –Germany
Phone: [phone] / 20 44 –www.seikom-electronic.de –Email: [e-mail] 7
4. Maintenance and Service
4.1 Definitions
Definitions according to IEC 60079-17:
Maintenance and Repair: A combination of activities, carried out to maintain an object in a certain
condition or to regain this condition, which satisfies the requirements of the relevant specifications and
ensures the ability to perform the demanded functions.
Inspection: An activity, involving the thorough investigation of an object, with the aim of obtaining a
reliable conclusion regarding the condition of the object, which is conducted without removal of the object,
or if necessary with partial removal, complemented by actions such as measurements.
Visual Inspection: A visual inspection is an examination during which visible faults may be recognized (e.
g. missing screws) without application of any tools or gaining further access.
Close Inspection: An inspection that exceeds the visual inspection, during which faults may be recognized
(e. g. loose screw) that require further access or the utilization of tools. Neither opening a housing nor
switching to zero potential is usually required for a close inspection.
Detailed Inspection: An inspection that exceeds the close inspection, enabling the detection of faults (e. g.
loose connections) that can only be recognized if a housing is opened and/or, if necessary, tools and testing
equipment are utilized.
a) Maintenance activities can only be performed by qualified personnel.
b) Accessories used within areas exposed to explosion hazards have to satisfy the requirements of the
European directives and national legislation.
c) Maintenance activities involving the removal of sensors can only be performed in areas without any
explosion hazards.
d) Only original parts, dedicated for the use within areas exposed to explosion hazards, can be used for
the replacement of components.
e) Products within the area exposed to an explosion hazard must be serviced and cleaned regularly. The
intervals must be determined by the operator according to the environmental stress on site.
Activity
Monthly visual
inspection
Close inspection
every 6 months
Detailed inspection
every 12 months
Visual check of the sensors regarding
damage, removal of accumulated dust
●
Inspection regarding intactness and
function
●
Inspection of the entire facility
Responsibility of the operator
Polluted air flow sensors shall only be cleaned in lukewarm soapy water. Before reinstallation the sensors
should be air-dried completely. Never use hard or sharp objects (e. g. screwdriver, steel brush) for cleaning.
5. Troubleshooting
Products used in areas exposed to explosion hazards cannot be altered or modified. Repair of the product can
only be performed by qualified and authorised personnel which has received specialised education in this
field.

Air Flow Monitoring
Operating Instructions for the Air Flow Sensors and Monitors of Series F3.xEx and NLSW75-AEx
SEIKOM-Electronic GmbH & Co. KG –Fortunastr. 20 –42489 Wülfrath –Germany
Phone: [phone] / 20 44 –www.seikom-electronic.de –Email: [e-mail] 8
Problem
Cause
Solution
NLSW75-AEx does not work
No or wrong supply voltage
Check supply voltage
and connection
NLSW75-AEx cannot
identify flow
Sensor not installed correctly or the measured
range does not correspond to the technical data
Check installation
conditions and
installation
NLSW75-AEx shows
changed response behaviour
Sensor is polluted
Clean the sensor with
lukewarm soapy
water
NLSW75-AEx switches in
case of fast temperature
increase
The temperature gradient exceeds the technical
data
Re-adjust switch-
point/Reinforcement/
Zero point
6. Disposal
The disposal of the packaging materials and used parts must be in accordance with the national regulations
relevant in the location of operation of the product.
7. Labelling of the Air Flow Sensors F3.xEx
Every air flow sensor of the series F3.xEx carries a readable label which specifies the required explosion
protection class as specified below. The label cannot be removed. Generally, a readable identification of the
required explosion protection class in field use must be attached before the first use of the product.
SEIKOM-Electronic GmbH & Co.KG
Fortunastr. 20
D-42489 Wülfrath
Type: F3.*Ex
[Serial number]
C [Year of construction]
TFR: 18 ATEX003
EII 3G Ex ic IIC T4 Gc
0 °C ≤ Ta ≤ 60 °C
A sensor, that was once used in a not intrinsically safe electric circuit, cannot be used in intrinsically safe
electric circuits subsequently.
8. General description NLSW75-AEx
With this air flow monitor, you can depict air flows via an externally connected display or realize a min-
max-control via a limiting value transmitter. The monitor also has a continuously adjustable change-over
contact. You can adjust the analog outputs by setting 0V in the absence of flow and 10V at maximum flow
(20mA). The switch-point of the output relay can be adjusted in the range of 0 to 10V.

Air Flow Monitoring
Operating Instructions for the Air Flow Sensors and Monitors of Series F3.xEx and NLSW75-AEx
SEIKOM-Electronic GmbH & Co. KG –Fortunastr. 20 –42489 Wülfrath –Germany
Phone: [phone] / 20 44 –www.seikom-electronic.de –Email: [e-mail] 9
9. Technical Data of the Air Flow Monitors NLSW75-AEx
Type
NLSW75-AEx
NLSW75-AEx
NLSW75-AEx
Article-No
70789/DC/Ex
60620/Ex
70789/AC/Ex
Operating voltage
24 V DC
230 VAC
24 V AC
Voltage tolerance
± 5 %
Signal display, voltage
Green LED
Max. power consumption
5 VA/W
5 VA/W
5 VA/W
Permissible ambient
temperature
-10..+50 °C
Overvoltage category
II
Signal output flow
1 change-over contact
Current and contact rating
250 V AC, 6 A, 1,5 kVA
Switch function in case of
flow
Relay contact changes
Signal display flow
Yellow LED
Analog outputs
0…10V/4…20mA relative
Burden
200Ω
Applicable range of media
temperature
0 °C…+60 °C
Switch-point
Adjustable via potentiometer
Measurable range
0,5 m/s…20 m/s, adjustable via potentiometer
Flow sensors
F3Ex, F3.1Ex, F3.2Ex, F3.3Ex
Z-Barrier
2 pcs. included in delivery
Electrical connection
16 clips, 2,5 mm²
Casing
Standard housing N75
Casing dimensions
L=112 mm; W=75 mm; H=73 mm
Protection class casing
IP20
Protection class clips
IP20
Mark of conformity
10.Installation of the Air Flow Monitors NLSW75-AEx
The air flow monitors of the series NLSW75-AEx must be mounted, together with the safety barriers,
outside of the area exposed to an explosion hazard. The protection class IP20 of the housing must be
considered.
Connection and start-up must be conducted by qualified personnel. The mandatory competence of qualified
personnel includes knowledge of the types of ignition protection as well as provisions and regulations
concerning equipment in ex-zones! Verify whether the classification (according to these instructions and the
labelling of the devices) is sufficient for the dedicated use.
The housing enables mounting on a profile rail NS35/7,5 according to DIN EN 50022-35. If the profile rail is
exposed to larger vibrations, it has to be mounted in a vibration-reducing manner. Please follow the
provisions of DIN EN 60034-14 (IEC34-14).

Air Flow Monitoring
Operating Instructions for the Air Flow Sensors and Monitors of Series F3.xEx and NLSW75-AEx
SEIKOM-Electronic GmbH & Co. KG –Fortunastr. 20 –42489 Wülfrath –Germany
Phone: [phone] / 20 44 –www.seikom-electronic.de –Email: [e-mail] 10
Furthermore, the following points must be considered:
a) For the installation of an intrinsically safe electrical circuit a block diagram (system description) is
required, which must be supplied by the builder or operator
b) The installation can only be conducted in a cleared status
c) The start-up can only be performed after the mounting and electrical connection have been finished
d) The permissible ambient conditions specified in this operating instruction cannot be exceeded
ATTENTION: It is not permitted to connect the connection “N” of the supply voltage with b2 (strand
no. 2) of the sensor wire when using a 24 AC and DC air flow monitor of the series NLSW75-AEx!
10.1 Start-Up and Switch-Point Adjustment
The relation between air flow velocity and resistance change is non-linear. In the lower section (small flow)
the change of resistance is large. The change of resistance becomes smaller with constant increase of the
flow velocity in the upper section. This characteristic should be considered when adjusting the switch-point.
Moreover, the following requirements must be taken into account:
Small changes of flow in the high section of flow velocity: The switch-point must be chosen close to the
usual value of the flow, because the changes of the measured value are very small with changing flow. Since
the temperature compensation lags behind the real change of temperature, such a kind of switch-point
adjustment is only possible in use cases with slow temperature change.
Small changes of flow in the small section of flow velocity: The switch-point can be selected with a certain
distance to the usual value of the flow, since changes in the measured value are large for changing flow.
Temperature changes are not influencing the switching behavior.
Large changes of flow: In this case a yes/no response is desired (e. g. to verify that a fan is working or not).
Therefore a large interval may be selected, so that neither temperature changes nor turbulences may impact
the switching behavior.
For the start-up the following approach is recommended:
1. Install the air flow sensor and monitor according to the instructions.
2. Connect analog measuring equipment.
3. Set potentiometer “Reinforcement” to minimum sensitivity (left stop).
4. Switch Supply voltage; the green LED lights up and the device is ready to operate within two
seconds.
5. Without flow, adjust the the output voltage or current with potentiometer “Zero Point” to 0V or
4mA.
6. Activate the flow generation.
7. At maximum flow, adjust the output voltage or current to 10V or 20mA with potentiometer
“Reinforcement”.
8. Turn the potentiometer „switch-point“ slowly towards maximum until the yellow LED lights up and
the potential-free switcher operates; in order to obtain stable switching conditions the potentiometer
“airflow” should be turned slightly over the switch-point.
9. Review the settings: In order to review the settings turn the air flow off, the yellow LED
extinguishes, the potential-free switcher operates, activate the air flow, the yellow LED lights up, the
potential-free switcher operates again.
The air flow monitor is now adjusted to monitoring function. Please find the relation between air flow and
switching position of the potential-free switcher below:
Flow ≥ Threshold value
Signal output switches
yellow LED „airflow“ lights up
Flow < Threshold value
Signal output does not operate
yellow LED „airflow“ does not light up

Air Flow Monitoring
Operating Instructions for the Air Flow Sensors and Monitors of Series F3.xEx and NLSW75-AEx
SEIKOM-Electronic GmbH & Co. KG –Fortunastr. 20 –42489 Wülfrath –Germany
Phone: [phone] / 20 44 –www.seikom-electronic.de –Email: [e-mail] 11
Please do not hesitate to contact us in case of questions or problems.
Technical development and errors reserved Revision status: 04/2021