Pepperl+Fuchs NCN3-F31K2 Series User manual

ISO9001
2
Functional Safety
Inductive Dual Sensor
NCN3-F31K2(M)-N*-B*3-S
FACTORY AUTOMATION
MANUAL

With regard to the supply of products, the current issue of the following document is applicable:
The General Terms of Delivery for Products and Services of the Electrical Industry, published by the
Central Association of the Electrical Industry (Zentralverband Elektrotechnik und Elektroindustrie (ZVEI) e.V.)
in its most recent version as well as the supplementary clause: "Expanded reservation of proprietorship"
Functional Safety NCN3-F31K2(M)-N*-B*3-S

Functional Safety NCN3-F31K2(M)-N*-B*3-S
Content
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1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.1 Content of this Document. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.2 Safety Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.3 Symbols Used . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2 Product Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.1 Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.2 Interfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.3 Marking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.4 Standards and Directives for Functional Safe. . . . . . . . . . . . . . . . . . . . 8
3 Planning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.1 System Structure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.2 Assumptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
3.3 Safety Function and Safe State . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
3.4 Characteristic Safety Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3.5 Useful Lifetime . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
4 Mounting and Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
4.1 Mounting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
4.2 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
4.3 Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
5 Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
5.1 Proof Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
6 Maintenance and Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
7 List of Abbreviations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

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Functional Safety NCN3-F31K2(M)-N*-B*3-S
Introduction
1 Introduction
1.1 Content of this Document
This document contains safety-relevant information for usage of the device.
You need this information to use your product throughout the applicable stages of the product
life cycle. These can include the following:
• Product identification
• Delivery, transport, and storage
• Mounting and installation
• Commissioning and operation
• Maintenance and repair
• Troubleshooting
• Dismounting
• Disposal
The documentation consists of the following parts:
• Present document
• Instruction manual
• Manual
• Datasheet
Additionally, the following parts may belong to the documentation, if applicable:
• EU-type examination certificate
• EU declaration of conformity
• Attestation of conformity
• Certificates
• Control drawings
• FMEDA report
• Assessment report
• Additional documents
For more information about Pepperl+Fuchs products with functional safety,
see www.pepperl-fuchs.com/sil.
Note!
For full information on the product, refer to the further documentation on the Internet
at www.pepperl-fuchs.com.

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Introduction
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1.2 Safety Information
Target Group, Personnel
Responsibility for planning, assembly, commissioning, operation, maintenance,
and dismounting lies with the plant operator.
Only appropriately trained and qualified personnel may carry out mounting, installation,
commissioning, operation, maintenance, and dismounting of the product. The personnel
must have read and understood the instruction manual and the further documentation.
Intended Use
The device is only approved for appropriate and intended use. Ignoring these instructions
will void any warranty and absolve the manufacturer from any liability.
The device is developed, manufactured and tested according to the relevant safety standards.
Use the device only
• for the application described
• with specified environmental conditions
• with devices that are suitable for this safety application
Improper Use
Protection of the personnel and the plant is not ensured if the device is not used according
to its intended use.

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Functional Safety NCN3-F31K2(M)-N*-B*3-S
Introduction
1.3 Symbols Used
This document contains symbols for the identification of warning messages
and of informative messages.
Warning Messages
You will find warning messages, whenever dangers may arise from your actions.
It is mandatory that you observe these warning messages for your personal safety
and in order to avoid property damage.
Depending on the risk level, the warning messages are displayed in descending order
as follows:
Informative Symbols
Action
This symbol indicates a paragraph with instructions. You are prompted to perform
an action or a sequence of actions.
Danger!
This symbol indicates an imminent danger.
Non-observance will result in personal injury or death.
Warning!
This symbol indicates a possible fault or danger.
Non-observance may cause personal injury or serious property damage.
Caution!
This symbol indicates a possible fault.
Non-observance could interrupt the device and any connected systems and plants,
or result in their complete failure.
Note!
This symbol brings important information to your attention.

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Product Description
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2 Product Description
2.1 Function
General
The device is an inductive dual sensor. Dual sensors are used, for example, to detect the final
positions of valve positions in valve actuators.
Inductive dual sensors consist of 2 sensor circuits arranged one above the other.
Each sensor has its own coil. If a measuring plate is inside the sensing range of one
of the coils, the magnetic field of the coil is influenced and an electrical switching signal
is generated.
The device is a NAMUR sensor with 2 independent sensor circuits in 2-wire configuration.
The device transmits the binary signal according to NAMUR to a connected control unit.
A control unit can, e. g., be a switch amplifier or an I/O card in a PLC.
NCN3-F31K2(M)-N4-B*3-S
The sensor has two separate sensor circuits with NC function (normally-closed).
The device is in high impedance state when a measuring plate is located within the sensing
range of the respective sensor circuit.
The sensor has a rated operating distance sn of 3 mm.
NCN3-F31K2-N5-B*3-S
The sensor has two sensor circuits. One sensor circuit of these sensor circuits is activated
depending on the polarity of the supply voltage. The active sensor circuit is in high impedance
state when a measuring plate is located within the sensing range of this sensor circuit.
The sensor has a rated operating distance sn of 3 mm.
2.2 Interfaces
The device has the following interfaces.
• Safety relevant interface: device output
• Non-safety relevant interface: none
Note
See corresponding datasheets for further information.
Note
For corresponding connections see datasheet.

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Functional Safety NCN3-F31K2(M)-N*-B*3-S
Product Description
2.3 Marking
2.4 Standards and Directives for Functional Safe
Device-specific standards and directives
Pepperl+Fuchs Group
Lilienthalstraße 200, 68307 Mannheim, Germany
Internet: www.pepperl-fuchs.com
NCN3-F31K2-N4-B13-S
NCN3-F31K2-N4-B33-S
NCN3-F31K2M-N4-B13-S
NCN3-F31K2M-N4-B23-S
NCN3-F31K2-N5-B13-S
NCN3-F31K2-N5-B33-S
Up to SIL 2
Functional safety IEC/EN 61508, part 1 –2, edition 2010:
Functional safety of electrical/electronic/programmable electronic
safety-related systems (manufacturer)

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Planning
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3 Planning
3.1 System Structure
3.1.1 Low Demand Mode of Operation
If there are two control loops, one for the standard operation and another one for
the functional safety, then usually the demand rate for the safety loop is assumed to be less
than once per year.
The relevant safety parameters to be verified are:
• the PFDavg value (average Probability of dangerous Failure on Demand) and
the T1value (proof test interval that has a direct impact on the PFDavg value)
• the SFF value (Safe Failure Fraction)
• the HFT architecture (Hardware Fault Tolerance)
3.1.2 High Demand or Continuous Mode of Operation
If there is only one safety loop, which combines the standard operation and safety-related
operation, then usually the demand rate for this safety loop is assumed to be higher than once
per year.
The relevant safety parameters to be verified are:
• the PFH value (Probability of dangerous Failure per Hour)
• Fault reaction time of the safety system
• the SFF value (Safe Failure Fraction)
• the HFT architecture (Hardware Fault Tolerance)
3.1.3 Safe Failure Fraction
The safe failure fraction describes the ratio of all safe failures and dangerous detected failures
to the total failure rate.
SFF = (s + dd) / (s + dd + du)
A safe failure fraction as defined in IEC/EN 61508 is only relevant for elements or (sub)systems
in a complete safety loop. The device under consideration is always part of a safety loop but
is not regarded as a complete element or subsystem.
For calculating the SIL of a safety loop it is necessary to evaluate the safe failure fraction
of elements, subsystems and the complete system, but not of a single device.

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Functional Safety NCN3-F31K2(M)-N*-B*3-S
Planning
3.2 Assumptions
The following assumptions have been made during the FMEDA:
• Failure rate based on the Siemens standard SN 29500.
• Failure rates are constant, wear is not considered.
• External power supply failure rates are not included.
• The safety-related device is considered to be of type A device with a hardware fault
tolerance of 0.
• The device will be used under average industrial ambient conditions comparable
to the classification "stationary mounted" according to MIL-HDBK-217F.
Alternatively, operating stress conditions typical of an industrial field environment similar
to IEC/EN 60654-1 Class C with an average temperature over a long period of time
of 40 ºC may be assumed. For a higher average temperature of 60 ºC, the failure rates
must be multiplied by a factor of 2.5 based on experience. A similar factor must be used
if frequent temperature fluctuations are expected.
SIL 2 Application
Only use the device in SIL 2 applications in combination with a control unit according
to EN 60947-5-6 (NAMUR).
• The device claims less than 25 % of the total failure budget for a SIL 2 safety loop.
• For a SIL 2 application operating in low demand mode the total PFDavg value
of the SIF (Safety Instrumented Function) should be smaller than 1 x 10-2,
hence the maximum allowable PFDavg value would then be 2.5 x 10-3.
• For a SIL 2 application operating in high demand mode the total PFH value
of the SIF should be smaller than 1 x 10-6 per hour, hence the maximum allowable
PFH value would then be 2.5 x 10-7 per hour.
• Since the safety loop has a hardware fault tolerance of 0 and it is a type A device,
the SFF must be > 60 % according to table 2 of IEC/EN 61508-2 for a SIL 2 (sub) system.

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Planning
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3.3 Safety Function and Safe State
Safe State
The safe state of the device is the high impedance state (low current).
Applications with control units or safety functions where the safe state is the low impedance
state (high current) were not evaluated.
Safety Function
Figure 3.1 Distance values for the design of the safety function (abstract figure)
The NAMUR sensor signals the safe state when the reference object is inside of the operating
distance of the respective sensor (s < Sao). The assured operating distance Sao is 2.1 mm.
This assured operating distance is valid when using a reference object with a size
of 12 mm x 12 mm x 0.4 mm, made of stainless steel 1.4305.
To ensure the safety of the safety loop according to SIL 2, only use control units according
to EN 60947-5-6 (NAMUR).
Reaction Time
The reaction time for all safety functions is < 1 ms.
sCurrent operating distance
snRated operating distance
Sao Assured operating distance of a PDBB
Sar Assured release distance of a PDDB
Sao
Sar
sn
s
0
Note
See corresponding datasheets for further information.

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Functional Safety NCN3-F31K2(M)-N*-B*3-S
Planning
3.4 Characteristic Safety Values
The characteristic safety values like PFD, SFF, HFT and T1 are taken from the
SIL report/FMEDA report. Observe that PFD and T1 are related to each other.
The function of the devices has to be checked within the proof test interval (T1).
Parameter Characteristic values
Assessment type and
documentation
Full assessment
Device type A
Mode of operation Low Demand Mode or High Demand Mode
HFT 0
Safety function High impedance state, depending on the position of the measuring plate
SIL 2
in combination with a control unit according to EN 60947-5-6 (NAMUR)
SC 3
s1
1"No effect failures" are not influencing the safety function and are therefore not included in SFF and in the failure rates of the safety
function.
107 FIT
du 66 FIT
total (safety function) 173 FIT
SFF 162 %
PFH 6.55 x 10-8 1/h
PFDavg for T1 = 1 year 2.87 x 10-4
PFDavg for T1 = 2 years 5.74 x 10-4
PFDavg for T1 = 5 years 1.43 x 10-3
MTTFd1730 years
Useful life time 20 years
Reaction time 2
2Step response time, also valid under fault conditions (including fault detection and fault reaction)
< 1 ms
Table 3.1

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Planning
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3.5 Useful Lifetime
Although a constant failure rate is assumed by the probabilistic estimation this only applies
provided that the useful lifetime of components is not exceeded. Beyond this useful lifetime,
the result of the probabilistic estimation is meaningless as the probability of failure significantly
increases with time. The useful lifetime is highly dependent on the component itself and
its operating conditions – temperature in particular. For example, the electrolytic capacitors
can be very sensitive to the operating temperature.
This assumption of a constant failure rate is based on the bathtub curve, which shows
the typical behavior for electronic components.
Therefore it is obvious that failure calculation is only valid for components that have this
constant domain and that the validity of the calculation is limited to the useful lifetime
of each component.
It is assumed that early failures are detected to a huge percentage during the installation
and therefore the assumption of a constant failure rate during the useful lifetime is valid.
The standard EN/ISO 13849-1:2015 proposes a useful lifetime TM of 20 years for devices
used within industrial environments. This device is designed for this lifetime.
Observe that the useful lifetime can be reduced if the device is exposed to the following
conditions:
• highly stressful environmental conditions such as constantly high temperatures
• temperature cycles with high temperature differences
• permanent repeated mechanical stress (vibration)
Please note that the useful lifetime refers to the (constant) failure rate of the device.
The effective lifetime can be higher.

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Functional Safety NCN3-F31K2(M)-N*-B*3-S
Mounting and Installation
4 Mounting and Installation
Mounting and Installing the Device
1. Observe the safety instructions in the instruction manual.
2. Observe the information in the manual.
3. Observe the requirements for the safety loop.
4. Connect the device only to devices that are suitable for this safety application.
5. Check the safety function to ensure the expected output behavior.
4.1 Mounting
Mounting the Measuring Plate
1. If you are using a custom-specific measuring plate, check the operating distance
in your application under realistic environmental conditions.
The measuring plate is suitable if the measured value does not differ
by more than 10 % from the rated operating distance.
2. Fasten the measuring plate so that the measuring plate does not come loose or get lost.
4.2 Installation
Connecting the Sensor
1. Connect the device in safety applications up to SIL 2 to a control unit according
to EN 60947-5-6 (NAMUR).
Observe the limitations, see chapter 1.2.
2. Observe that the insulation resistance must be greater than 1 M.
Insulate the single wires from any other electrical connections.
3. Observe that the loop resistance must be less than 50 .
4.3 Configuration
A configuration of the device is not necessary and not possible.
Danger!
Danger to life from missing safety function
An incorrectly mounted, incorrectly positioned or missing measuring plate can lead to failure
of the safety loop.
• Fasten the measuring plate in a suitable manner.
• For SN sensors: Do not remove the measuring plate.

Functional Safety NCN3-F31K2(M)-N*-B*3-S
Operation
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5 Operation
Operating the device
1. Observe the safety instructions in the instruction manual.
2. Observe the information in the manual.
3. Use the device only with devices that are suitable for this safety application.
4. Correct any occurring safe failures within 8 hours. Take measures to maintain
the safety function while the device is being repaired.
5.1 Proof Test
If you perform a proof test for the safety loop, the following steps are necessary:
• Check the device for housing damages. If moisture penetrates into the device
or internal components of the device are damaged, this can lead to unpredictable effects.
• Check that the device is working correctly. If the device is not working correctly
or not working, replace the device.
For this proof test, no proof test coverage (PTC) can be claimed as only a full functional test
with the defined reference object over the temperature range can reveal an unacceptable
dislocation of the switching point (PTC = 100 %). But the safety characteristic values
are considered low enough to continually manage without proof test.
Danger!
Danger to life from missing safety function
If the safety loop is put out of service, the safety function is no longer guaranteed.
• Do not deactivate the device.
• Do not bypass the safety function.
• Do not repair, modify, or manipulate the device.

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Functional Safety NCN3-F31K2(M)-N*-B*3-S
Maintenance and Repair
6 Maintenance and Repair
Maintaining, Repairing or Replacing the Device
In case of maintenance, repair or replacement of the device, proceed as follows:
1. Implement appropriate maintenance procedures for regular maintenance of the safety loop.
2. While the device is maintained, repaired or replaced, the safety function does not work.
Take appropriate measures to protect personnel and equipment while the safety function
is not available.
Secure the application against accidental restart.
3. Do not repair a defective device. A defective device must only be repaired
by the manufacturer.
4. If there is a defect, always replace the device with an original device.
Danger!
Danger to life from missing safety function
Changes to the device or a defect of the device can lead to device malfunction.
The function of the device and the safety function is no longer guaranteed.
Do not repair, modify, or manipulate the device.

Functional Safety NCN3-F31K2(M)-N*-B*3-S
List of Abbreviations
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7 List of Abbreviations
DC Diagnostic Coverage of dangerous faults
FIT Failure In Time in 10-9 1/h
FMEDA Failure Mode, Effects, and Diagnostics Analysis
sProbability of safe failure
dd Probability of dangerous detected failure
du Probability of dangerous undetected failure
no effect Probability of failures of components in the safety loop that have
no effect on the safety function.
not part Probability of failure of components that are not in the safety loop
total (safety function) Probability of failure of components that are in the safety loop
HFT Hardware Fault Tolerance
MTBF Mean Time Between Failures
MTTFDMean Time To dangerous Failure
MTTR Mean Time To Restoration
OSSD Output Signal Switching Device
PDDB Proximity Device with Defined Behaviour under fault conditions
PFDavg Average Probability of dangerous Failure on Demand
PFH Average frequency of dangerous failure per hour
PL Performance Level
PLC Programmable Logic Controller
PTC Proof Test Coverage
sCurrent operating distance
Sao Assured operating distance of a PDDB
Sar Assured release distance of a PDDB
snRated operating distance
SC Systematic Capability
SFF Safe Failure Fraction
SIL Safety Integrity Level
T1Proof Test Interval

Subject to modifications
Copyright PEPPERL+FUCHS • Printed in Germany
www.pepperl-fuchs.com
FACTORY AUTOMATION –
SENSING YOUR NEEDS
Worldwide Headquarters
Pepperl+Fuchs Group
68307 Mannheim · Germany
Tel. [phone]
E-mail: [email protected]
USA Headquarters
Pepperl+Fuchs Inc.
Twinsburg, Ohio 44087 · USA
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E-mail: [email protected]
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Company Registration No. 199003130E
Singapore 139942
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E-mail: [email protected]
DOCT-6036B
11/2019