Seikom Electronic NLSW 45-3 Ex SIL2 User manual

Operating
instructions
NLSW®45-3 Ex SIL2
24 V AC, 24 V DC, 230 V AC

Version 1.0

Operating
instructions
NLSW®45-3 Ex SIL2
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The installation company and the system operator are responsible for observing and
complying with the relevant national Ex regulations.
Static charges on plastic and cable parts as well as interference radiation must be avoided.
Protect devices effectively against damage.
The sensor cable must be laid securely and effectively protected against damage.

Operating
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NLSW®45-3 Ex SIL2
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CONTENTS
CONTENTS ......................................................................................................................................3
1. SAFETY INSTRUCTIONS ..........................................................................................................4
1.1 General safety instructions ..........................................................................................................4
1.2 Intended use................................................................................................................................5
2. GENERAL INFORMATION ON EXPLOSION PROTECTION .............................................................5
2.1 Electrical circuit diagram for Ex-i ..................................................................................................6
2.2 Intrinsically safe characteristics.....................................................................................................7
2.3 Properties of the various sensor types ..........................................................................................7
2.4 Type code ...................................................................................................................................7
2.5 Dimensions of the air flow sensors F3.x Ex SIL2 ...........................................................................8
2.6 Temperature class ......................................................................................................................8
3. GENERAL INFORMATION..........................................................................................................8
3.1 Field of application and practical use...........................................................................................8
3.2 Functionality................................................................................................................................9
4. TECHNICAL DATA ...................................................................................................................10
4.1 Device dimensions ....................................................................................................................11
4.2 Labeling of the sensors (type plate) ............................................................................................11
5. INSTALLATION AND COMMISSIONING ......................................................................................12
5.1 Installation conditions for air flow sensors F3.x Ex SIL2 ...............................................................13
5.2 Installation.................................................................................................................................14
5.3 Electrical connection .................................................................................................................14
5.4 Commissioning the device.........................................................................................................15
5.5 Switching point adjustment........................................................................................................16
6. SERVICING AND MAINTENANCE ...............................................................................................17
6.1 Definition of terms according to IEC 60079-17.............................................................................17
7. TROUBLESHOOTING .............................................................................................................18
8. DISPOSAL ...............................................................................................................................19
9. EU DECLARATION OF CONFORMITY....................................................................................20

Operating
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1. SAFETY INSTRUCTIONS
1.1 General safety instructions
Please read the product description carefully before using the device. Make sure that the
product is fully suitable for your application.
Improper or improper use can lead to malfunctions of the device or to undesirable effects on your
application. For this reason, installation, electrical connection, commissioning, operation and
maintenance of the device may only be carried out by trained personnel.
The following standards were taken into account when evaluating the product:
a) IEC 60079-0:2017 Ed. 7 "Potentially explosive atmospheres - Part 0: Equipment -
General requirements"
b) IEC 60079-11:2011 Ed. 6 + Corr. 2012 / EN 60079-11:2012 "Potentially explosive
atmospheres - Part 11: Equipment protection by intrinsic safety 'i'"
c) TRGS 727:2016 "Avoidance of ignition hazards due to electrostatic charge"
The sensor corresponds to the state of the art and is safe to operate. The sensor may pose a
residual risk if it is used and operated improperly by untrained personnel.
Every person responsible for the installation, commissioning, maintenance or repair of the product
must have read and understood the operating instructions and in particular the safety instructions.
a) When selecting and operating a product as intended, follow the general rules of
technology.
b) All connected electrical and mechanical equipment must be suitable for the respective
application.
c) Observe the information in these operating instructions as well as the operating
conditions and permissible data indicated on the imprints/type plates of the respective
products.
d) Ensure that only the product ignition protection types corresponding to the zones are
installed.
e) The product is only approved for proper and intended use in a normal industrial
atmosphere. Immersion in liquids is not permitted.
f) It must be ensured that no falling objects can hit the product. In combination with rust,
light metal and kinetic energy, an exothermic ignitable reaction can be caused.
g) The operator must ensure lightning protection for the entire system in accordance with
local regulations.
h) It is the responsibility of the installer to ensure that the sensors function properly in
conjunction with the individual evaluation devices and are approved for the intended
use.
i) The intrinsically safe connection - including the sensors - must be made via
approved evaluation devices, which may have to be equipped with suitable Zener
barriers or switching amplifiers.

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1.2 Intended use
a) To ensure safe operation, the products may only be used in accordance with the
information in the operating instructions. During use, the legal and safety regulations
required for the respective application must also be observed. This also applies to the
use of accessories.
b) If the instructions given in this excerpt are not observed or if the product is handled
improperly, our liability shall lapse. In addition, the warranty on products and spare parts
is void.
c) The products are not safety elements in the sense of the intended use.
d) Only original parts from the manufacturer may be used.
2. GENERAL INFORMATION ON EXPLOSION PROTECTION
The intrinsically safe air flow sensor measures air flow velocities in the range of
0.1 20.0 m/s according to the calorimetric measuring principle. Depending on the functional principle,
either the
degree of cooling (cooling method) or the heating power required to bring the heating element to a
constant temperature (constant temperature method) is used as an indicator of the flow rate.
The air flow sensor is intended for commercial installations and may only be used in accordance
with the specifications in the technical documentation from SEIKOM-Electronic GmbH & Co.KG
and the information on the type plate. It is only operated together with certified products via an
intrinsically safe circuit that is powered by a safety barrier. They comply with the applicable
standards and regulations.
The installation regulations (e.g. EN 60079-14) for systems in potentially explosive atmospheres
must be observed.
Further important details can be found in the corresponding EC type examination certificate.
The requirements for simple electrical equipment that apply to Zone 1 potentially explosive gas
atmospheres in accordance with EN 60079-11 are met.
The air flow sensor can be used as follows, in accordance with the type plate:
⮚ In Zone 2 (Gas-Ex, EPL Gc) in explosion groups IIA, IIB and IIC
The qualification with regard to the surface temperature is T4. The equipment is a source of
ignition for all gases, vapors and mists with an ignition temperature > 135 °C.
The permissible ambient temperature range for the air flow sensor is from 0°C ≤Ta ≤60°C. The
permissible ambient temperature range for the NLSW45-3 Ex SIL2 evaluation electronics is from
-20°C ≤Ta ≤50°C. The permissible media temperature (air flow sensor) is 0°C ≤T ≤60°C.
The self-heating of the air flow sensors is generally negligible; in the event of a fault, the
permissible limit values of temperature class T4 can be reached.

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2.1 Electrical circuit diagram for Ex-i
When installing, please note that the supplied Zener barriers BZE804 and BZE805 have
different values. If the barriers are interchanged, the NLSW45-3 Ex SIL2 airflow monitor
will not function properly.

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2.2 Intrinsically safe characteristics
Type
Value
Ui
25 VDC
Ii
80 mA
Pi
0.35 W @ 40°C
0.24 W @ 110°C
Ci
Negligible
Li
Negligible
2.3 Properties of the various sensor types
Type
F3.x Ex SIL2
Article no.
50276ExSIL2/[Eintauchtiefe]
Immersion depth
50 mm (F3 Ex SIL2), 130 mm (F3.1 Ex SIL2), 165 mm (F3.2 Ex SIL2),
300 mm (F3.3 Ex SIL2), 400 mm (F3.4 Ex SIL2), 500 mm (F3.5 Ex SIL2)
Media temperature
0 °C ... 60 °C
Ambient temperature
0 °C ... 50 °C
Temperature gradient
30 K/min
Process connection
PG7 thread
Sensor tube material
MS58, nickel-plated brass
Compressive strength
10 bar
Electrical connection
2.5 m / 3 x 0.75 mm2
Protection class
IP67
Evaluation electronics
NLSW®45-3 Ex SIL2
Wire colors
Brown, black, gray, numbered (1, 2, 3)
2.4 Type code
Only one product type F3.x Ex SIL2 is manufactured, which differs only in the different sensor length.
See previous table.

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2.5 Dimensions of the air flow sensors F3.x Ex SIL2
Sensor type
Length A (in mm)
Length B (in mm)
F3 Ex SIL2
35
60
F3.1 Ex SIL2
115
140
F3.2 Ex SIL2
150
175
F3.3 Ex SIL2
285
310
F3.4 Ex SIL2
385
410
F3.5 Ex SIL2
485
510
2.6 Temperature class
The sensor is suitable for temperature class T4.
3. GENERAL INFORMATION
The NLSW45-3 Ex SIL2 air flow monitor is a flow monitor consisting of two air flow sensors and an
evaluation unit. The device works according to the calorimetric measuring principle. The NLSW45-3
Ex SIL2 complies with the SIL2 standards according to IEC 61508-5:2010. Both the circuitry in the
evaluation unit and the sensor have a redundant design.
3.1 Field of application and practical use
The electronic air flow monitors of the NLSW45-3 Ex SIL2 series are used for monitoring fans or
dampers, for air flow-dependent monitoring of humidifiers and electric heating registers in
accordance with DIN57100 Part 420 or for use in conjunction with DDC systems.

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General areas of application: Fan monitoring, extraction systems, supply air systems, mechanical
and plant engineering.
3.2 Functionality
Flow monitors of the NLSW45-3 Ex SIL2 series operate according to the calorimetric principle.
The relay of a device switches when the flow velocity reaches a preselected threshold value. The
calorimetric measuring principle is based on a heated, temperature-sensitive resistor. Heat is
extracted from the precision resistor by the flow in the medium. The temperature of the resistor
changes and with it its resistance value. This change is evaluated by the device. However, since
not only the flow velocity of the medium has an influence on the amount of heat dissipated, but
also its temperature, a correlation between flow and temperature must be established. This is
achieved by a second, temperature-dependent precision resistor in addition to the first. The
second precision resistor (temperature compensation) is not heated and is only used to measure
the temperature.

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4. TECHNICAL DATA
Type
NLSW®45-3 Ex SIL2
24 V AC
NLSW®45-3 Ex SIL2
24 V DC
NLSW®45-3 Ex SIL2
230 V AC
Item number
77029ACExSIL2_Gg
77029ACExSIL2_Gg
63377ExSIL2_Gg
Operating voltage
24 V AC
24 V DC
230 V AC 50/60 Hz
Voltage tolerance
± 5%
Overvoltage
category
II
Signal lamp
Tension
Green LEDs
Power consumption
5 VA
11 VA
Ambient temperature
temperature device
-20°C ... 50°C
Signal output
Flow
2 relay contacts (changeover contact)
Switching function for
Flow
Relay picks up
Electricity and
Contact load capacity
250 V AC, 8 A, 2 kVA
Minimum switching
power of the relays
10 mA / 5 V DC
Signal lamp
Flow
Yellow LEDs
Start-up bypass
5 s... 60 s
Signal lamp
Start-up bypass
Yellow LEDs
Media temperature
range
0°C ... 60°C
Temperature gradient
30 K/min
Switching point
setting
Adjustable via potentiometer
Measuring range
0.1 ... 20.0 m/s
Associated sensor
F3.x SIL2
Immersion depth
sensor
50 mm (F3 Ex SIL2), 130 mm (F3.1 Ex SIL2), 165 mm (F3.2 Ex SIL2),
300 mm (F3.3 Ex SIL2), 400 mm (F3.4 Ex SIL2), 500 mm (F3.5 Ex SIL2)
Process connection
PG7 thread
Sensor material
MS58, nickel-plated, optionally available in stainless steel
Compressive strength
10 bar
Electrical connection
14 Terminal plug, 2.5 mm²
Enclosure protection
class
IP65
Protection class Sensor
IP67
Degree of soiling
2
Housing dimensions
(L x W x H)
165 mm x 85 mm x 55 mm
SIL certification
SIL2 classification
IEC 61508 SIL 2: 03.2023, type A
More
Certifications
CE, UKCA

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4.1 Device dimensions
4.2 Labeling of the sensors (type plate)
Each airflow sensor of the F3.x Ex SIL2 series is marked with a legible marking for the type of
explosion protection required in the field as follows. This marking must not be removed.
SEIKOM-Electronic GmbH & Co KG
Fortunastr. 20
D-42489 Wülfrath
Type: F3.x Ex SIL2
[Serial number]
[Year of construction]
TFR: 18 AT Ex 0003
E II 3G Ex ic IIC T4 Gc
0 °C ≤Ta ≤60 °C
As a general rule, legible marking for the type of explosion protection required in the field must be
carried out before the product is put into operation for the first time.
A sensor that has already been operated in non-intrinsically safe circuits may no longer be used in
intrinsically safe circuits.

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5. INSTALLATION AND COMMISSIONING
Installation and commissioning must be carried out by authorized and qualified personnel.
Depending on the IP protection rating, the time for cleaning the operating equipment (dust deposits)
must be specified. Other important facts:
a) The product may only be put into operation in Zone 2 (Cat. 3G, EPL Gc) or Zone 1 (Cat.
2G, EPL Gb in intrinsically safe circuits by specialists with a qualification similar to a
competent person in accordance with TRBS 1203.
b) The information on the rating plate must be observed.
c) The products may only be used in a normal industrial atmosphere. The manufacturer
must always be consulted if aggressive substances are present in the air. The products
must be protected accordingly in adverse ambient conditions.
d) The product may only be operated when the housing is fully assembled and
undamaged. In the event of possible damage, the operator may have to take into
account zone entrainment; in addition, operation is not permitted if the housing is
damaged.
e) The ambient conditions specified in the operating instructions must be complied with
and the device must be protected against adverse ambient conditions.
f) Heat radiation from external products/components must also be taken into account.
g) The sensors must be protected against liquids and/or soiling.
h) Stuck parts (e.g. due to frost or corrosion) must not be loosened by force if an explosive
atmosphere is present. Icing must therefore be avoided.
i) The sensors may only be exposed to low vibrations, see also IEC 34-14.
j) To ensure the dissipation of electrostatic charges, the national requirements must be
taken into account.
k) In particular, isolated capacities must be prevented.
l) The sensor housing should be electrostatically connected to the equipotential bonding; a
limit value of1 MΩ is permissible.
m) Only Zener barriers or switching amplifiers whose output circuits are approved for use in
potentially explosive atmospheres may be used. In Europe, use in Zone 1 requires an
EC type examination certificate for the equipment concerned issued by a notified body
for explosion protection.
n) The total power Po of all supply devices must be less than or equal to the power Pi
of the sensors.
o) The voltage of the supply devices must be less than or equal to the voltage Ui of the
sensors.
p) The total current Io of the supply devices must be less than or equal to the current Ii of the
sensors.
q) A block diagram (system description) to be drawn up by the installer/operator is required
for the installation of the intrinsically safe circuit.
r) Equipotential bonding must be established between the earth connection and along the
intrinsically safe circuit when using a Zener barrier and the housing of the flow sensors.
s) The certificates, including the special conditions specified therein, must be taken into
account.

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t) Stuck parts of the product (e.g. due to frost or corrosion) must not be forcibly loosened if
an explosive atmosphere is present.
u) The sensors must not be used in systems in which cathodic systems for corrosion
protection are present. Although special precautions may make this possible, the
manufacturer must always be consulted. Parasitic currents must not be conducted via the
construction.
v) Within the potentially explosive area, installation may only be carried out in accordance with
the locally applicable installation regulations.
The following conditions must be observed (incomplete):
a) Installation and maintenance may only be carried out in an explosion-free atmosphere
and in compliance with the regulations applicable in the operator's country.
b) Additional precautions must be taken if the presence of hydrogen sulphide, ethylene
oxide and/or carbon monoxide is to be expected: these substances have a very low
ignition energy.
c) If these substances are present and if a substance of explosion group IIC is present and if
an explosive atmosphere is likely to be present, only non-sparking tools may be used.
5.1 Installation conditions for airflow sensors F3.x Ex SIL2
The following installation conditions must be observed for the F3.x SIL2 sensors:
▪ The sensor tip should be located in the center of the pipe if possible and must be fully
surrounded by the medium (air/gas).
▪ Align the mark on the sensors in the direction of the flow.
▪ The sensors must be mounted in the same pipe in such a way that they do not influence
each other (approx. 3 x D (pipe inner diameter) distance in a row or on the
same height in the channel) - see drawing below:
▪ For vertical ducts, the flow direction should ideally be from bottom to top.
▪ Maintain a free inlet section 5 x D upstream of the sensor and an outlet section 3 x D
downstream of the sensor.
▪ Only screw in the sensors via the hexagon of the sensor.
▪ The sensors are independent of the installation position.
▪ The sensors must be connected to the airflow monitor in accordance with the connection
diagram. Mixing up the connections will lead to malfunctions and possible damage.
▪ The air flow sensor must be connected to the air flow monitor in accordance with the
connection diagram. Mixing up the connections will lead to malfunctions and possibly
defects
▪ The screen (shielding) must be connected to the potential equalization (PA)

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▪ An extension of the sensor cable (shielded) is only permitted in a non-explosive
atmosphere and may not exceed a total length of 30 m with a minimum cross-section of
1.5 mm².
do not exceed
The following points must be observed for the connecting cable during operation:
▪ The temperature range for mobile installation is -5°C to +80°C; minimum bending radius
10 x cable diameter
▪ The temperature range for fixed installation is -40°C to +80°C; minimum bending radius
10 x cable diameter
The connecting cable used is not suitable for outdoor use or underground installation. Always
contact the manufacturer for deviating operating conditions.
5.2 Installation
It is mounted using the PG7 thread on the sensor housing. Mounting is also possible using the
enclosed PG7 nuts. The marking serves as an alignment aid to align the cross hole with the
sensors in the air flow. When commissioning with media temperatures below 0°C and strong air
currents, the start-up time of the device may be extended to 60 s until it is ready for operation.
5.3 Electrical connection
The mains connection (L1, N) must be established via a fused isolating switch with the usual fuses.
The general VDE regulations must always be observed during electrical installation (VDE0100,
VDE0113, VDE0160).
If a safety extra-low voltage is applied to the potential-free contact, ensure that the connecting
cables are sufficiently insulated up to the terminal point, as otherwise the double insulation to the
mains voltage side will be impaired. The current carrying capacity of the potential-free contact is
limited to 8 A.

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Color code: GY=grey | BK=black | BN=brown
5.4 Commissioning the device
The two potentiometers (purple) fixed with protective lacquer are set at the factory and must
not be adjusted.
The following procedure is recommended for commissioning and setting the devices:
a) Connect two suitable sensors (F3.x) to the device using the supplied terminals; sensor A
to channel A, sensor B to channel B (light blue).

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b) Connect the PLC or control unit to relay output A and B (green) using the terminals
supplied. Please note the NO/NC contact assignment and circuit.
c) Set the "Sensitivity" potentiometer (dark blue) for both channels to the left stop
(insensitive).
d) Set the "Start-up bypass" potentiometer (orange) to the desired start-up bypass time
approx. 5 s ... 60 s (left stop approx. 5 s/ right stop approx. 60 s) for both sensors.
e) Apply mains voltage (red); the green LEDs light up. The device is ready for operation
within 2 seconds.
f) The yellow LEDs light up (briefly) and go out again as soon as the set start-up bridging
time has elapsed. The relays are energized during this time.
g) Switch on the airflow generator.
h) Before setting the switching points, the device should run for at least 2 minutes under
operating conditions (with flow). The switching point setting at low flow rates requires a
sensitive setting on the potentiometer.
i) Slowly turn the "Sensitivity" potentiometer for channel A (dark blue) to the right until the
yellow LED lights up and the output relay is energized. To achieve stable switching
conditions, you should turn slightly beyond the switching point. Set the same switching
ratio for channel B.
Note: Depending on the installation position and air flow situation in the duct, small
switching differences between duct A and duct B are normal.
j) If the start-up bypass is preset, do not make this sensitivity setting until the start-up
bypass has expired and the yellow LED has gone out.
k) To check the flow monitoring, reduce or switch off the flow generation. The yellow LEDs
go out and the output relays de-energize.
The device is now set to monitoring function. Preset values of the
NLSW45-3 Ex SIL2:
▪ The switching hysteresis is fixed.
▪ The switching delay is 0.2 s as standard.
▪ The start-up delay is adjustable from 5 s to 60 s as standard.
5.5 Switching point adjustment
The relationship between air velocity and change in resistance is not linear. In the lower range
(small flows), the change in resistance is very large. In the upper range, the change in resistance is
always smaller for the same flow changes. When setting the switching point, it should therefore be
noted which change is to be monitored, as different settings have certain disadvantages. The
following requirements should be observed:
Small flow change in the high flow velocity range: The switching point must be selected very
close to the measured value of the normal flow, as the measured value change is very small when
the flow changes. As the temperature compensation has a certain delay compared to the actual
temperature change, such a switching point setting is only possible for applications with slow
temperature changes.
Small flow change in the low flow velocity range: The switching point can be selected with a
greater distance to the measured value of the normal flow, as the measured value change is large
when the flow changes. A change in temperature has no effect on the switching behavior.

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Large flow change: A 'yes/no' statement is usually required here (e.g. fan running or fan
stopped). Therefore, such a large safety distance can be selected that neither temperature
changes nor turbulence have an influence on the switching behavior.
The switching points are set on the evaluation unit of the airflow monitor.
6. SERVICING AND MAINTENANCE
6.1 Definition of terms according to IEC 60079-17
Maintenance and repair: A combination of all activities carried out to maintain or restore an item to
a condition that meets the requirements of the relevant specification and ensures the performance
of the required functions.
Inspection: An activity involving the careful examination of an object with the aim of making a
reliable statement about the condition of this object, whereby it is carried out without disassembly
or, if necessary, with partial disassembly, supplemented by measures such as measurements.
Visual inspection: A visual inspection is an inspection in which visible defects are detected without
the use of access equipment or tools, for example missing screws.
Close-up test: A test in which, in addition to the aspects of the visual inspection, faults such as
loose screws that can only be detected by using access equipment, e.g. steps (if necessary) and
tools, are detected. For close-up inspections, an enclosure does not usually need to be opened or
the equipment de-energized.
Detailed inspection: An inspection in which, in addition to the aspects of the close-up inspection,
defects such as loose connections, which can only be detected by opening housings and/or, if
necessary, using tools and test equipment, are detected.
a) Maintenance work may only be carried out by qualified persons.
b) Only accessories that meet all the requirements of European directives and national
legislation may be used in potentially explosive atmospheres.
c) Maintenance work involving disassembly of the sensors may only be carried out in an
explosion-free atmosphere.
d) Components may only be replaced with original spare parts that are also approved for
use in hazardous areas.
e) The products must be regularly maintained and cleaned in hazardous areas. The
intervals are determined by the operator according to the environmental conditions on
site.

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Activity
Visual
inspection
monthly
Close
inspection
every 6
months
Detailed
inspection
every 12
months
Visually check the
sensors for damage,
remove dust deposits
●
Testing for integrity and
function
●
Testing the overall
system
In the area of responsibility of the operator
Only clean dirty air flow sensors in lukewarm soapy water. After cleaning, allow to air dry
completely before refitting the air flow sensors. Never use hard or sharp objects (e.g.
screwdrivers, wire brushes, etc.) for cleaning.
7. TROUBLESHOOTING
The following instructions are intended as first aid if your airflow monitor is not working properly. If
you have any further questions, the SEIKOM Electronic team will be happy to help you at any time by
phone or e-mail.
Problem
Possible cause
Troubleshooting
Device does not work at all
No or incorrect mains voltage
connected
Check mains voltage and
connection.
Device does not detect any
flow (on one or both
channels)
Sensor(s) is/are not installed
correctly or the sensitivity on
the evaluation unit is not
correct
discontinued.
Check the installation
conditions and sensitivity
settings.
Flow rate is outside the
measuring range
Adjust the diameter of the
pipe to increase the flow
rate
or reduce them.
NLSW45-3 Ex SIL2
works but both channels
switch (very) differently.
Sensor of a channel not set
correctly or defective.
Check the sensor and
setting; if necessary,
replace and readjust the
sensor.
NLSW45-3 Ex SIL2 has
Changed response
behavior
Sensor is heavily soiled by the
medium (deposits on the
sensor)
Carefully clean the sensor
with water.
Never use hard objects
use for cleaning.
NLSW45-3 Ex SIL2
switches with rapid media
temperature increase
or lowering
Temperature gradient is
outside the specification
Check the temperature
gradients of the system
(max.
30 K/min). In the event of a fault