EN 298:2022

SLOVENSKI STANDARD
01-februar-2023
Nadomešča:
SIST EN 298:2012
Naprave za avtomatski nadzor gorilnikov in aparatov na plin ali tekoča goriva
Automatic burner control systems for burners and appliances burning gaseous or liquid
fuels
Feuerungsautomaten für Brenner und Brennstoffgeräte für gasförmige oder flüssige
Brennstoffe
Systèmes automatiques de commande pour brûleurs et appareils utilisant des
combustibles gazeux ou liquides
Ta slovenski standard je istoveten z: EN 298:2022
ICS:
27.060.10 Gorilniki na tekoče in trdo Liquid and solid fuel burners
gorivo
27.060.20 Plinski gorilniki Gas fuel burners
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 298
EUROPEAN STANDARD
NORME EUROPÉENNE
November 2022
EUROPÄISCHE NORM
ICS 27.060.01 Supersedes EN 298:2012
English Version
Automatic burner control systems for burners and
appliances burning gaseous or liquid fuels
Systèmes automatiques de commande pour brûleurs et Feuerungsautomaten für Brenner und
appareils utilisant des combustibles gazeux ou liquides Brennstoffgeräte für gasförmige oder flüssige
Brennstoffe
This European Standard was approved by CEN on 2 October 2022.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2022 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 298:2022 E
worldwide for CEN national Members.

Contents Page
European foreword . 4
Introduction . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 7
4 Classification. 16
4.1 Classes of control . 16
4.2 Groups of control . 16
4.3 Classes of control functions . 16
4.4 Types of DC supplied controls . 16
5 Test conditions and uncertainty of measurements . 16
6 Design and construction . 17
6.1 General. 17
6.2 Mechanical parts of the control . 17
6.3 Materials . 17
6.4 Gas connections . 17
6.5 Electrical parts of the control . 17
6.6 Protection against internal faults for the purpose of functional safety . 18
7 Performance . 21
7.1 General. 21
7.2 Leak-tightness . 21
7.3 Torsion and bending . 21
7.4 Rated flow rate . 21
7.5 Durability . 21
7.6 Performance tests for electronic controls . 21
7.7 Long-term performance for electronic controls . 22
7.8 Data exchange . 23
7.101 Functional requirements . 23
8 Electrical requirements . 33
8.1 General. 33
8.2 Protection by enclosure. 33
9 Electromagnetic compatibility (EMC) . 34
9.1 Protection against environmental influences . 34
9.2 Supply voltage variations below 85 % of rated voltage . 35
9.3 Voltage dips and interruptions . 35
9.4 Supply frequency variations . 36
9.5 Surge immunity tests . 36
9.6 Electrical fast transient/burst . 37
9.7 Immunity to conducted disturbances induced by radio frequency fields . 37
9.8 Immunity to radiated disturbances induced by radio frequency fields . 37
9.9 Electrostatic discharge tests . 37
9.10 Power frequency magnetic field immunity tests . 38
9.11 Harmonics and interharmonics including mains signalling at a. c. power port, low
frequency immunity tests . 38
10 Marking, instructions . 38
10.1 Marking . 38
10.2 Instructions . 38
10.3 Warning notice . 40
Annex A (informative) Abbreviations and symbols . 41
Annex B (informative) Leak-tightness tests for gas controls − volumetric method . 42
Annex C (informative) Leak-tightness tests for gas controls − pressure loss method . 43
Annex D (normative) Calculation of pressure loss into leakage rate . 44
Annex E (normative) Electrical/electronic component fault modes . 45
Annex F (normative) Additional requirements for safety accessories and pressure
accessories as defined in EU Directive 2014/68/EU . 47
Annex G (normative) Materials for pressurized parts . 48
Annex H (informative) Additional materials for pressurized parts . 49
Annex I (normative)  Requirements for controls used in DC supplied burners and appliances
burning gaseous or liquid fuels . 50
Annex J (normative)  Method for the determination of a Safety Integrity Level (SIL) . 52
Annex K (normative)  Method for the determination of a Performance Level (PL) . 53
Annex L (informative) Relationship between Safety Integrity Level (SIL) and Performance
Level (PL) . 54
Annex M (normative)  Reset functions . 55
Annex N (informative) Guidance document on Environmental Aspects . 56
Annex O (normative) Seals of elastomer, cork and synthetic fibre mixtures . 57
Annex AA (informative) Functional characteristics of automatic burner control systems, to
be given by the appliance standard . 58
Annex BB (informative) Fault modes of flame sensors . 59
Annex CC (informative) Functional diagrams of automatic burner control systems for oil 61
CC.1 Symbols . 61
CC.2 Explanations . 62
CC.3 Functional diagrams – Normal operation . 62
CC.4 Functional diagrams – protective response in case of abnormal operation in the
application . 64
Annex ZA (informative) Relationship between this European Standard and the essential
requirements of Directive 2009/142/EC aimed to be covered . 66
Annex ZB (informative) Relationship between this European Standard and the essential
requirements of Regulation (EU) 2016/426 aimed to be covered . 67
Annex ZC (informative) Relationship between this European Standard and the essential
requirements of Directive 2014/68/EU aimed to be covered . 68
Bibliography . 69
European foreword
This document (EN 298:2022) has been prepared by Technical Committee CEN/TC 58 “Safety and
control devices for burners and appliances burning gaseous or liquid fuels”, the secretariat of which is
held by BSI.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by May 2023, and conflicting national standards shall be
withdrawn at the latest by November 2025.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN 298:2012.
In comparison with the previous edition, the following significant changes have been incorporated in this
document:
a) alignment with EN 13611:2019, as impacted by EN 13611:2019/AC:2021;
b) inclusion of Annex J, Annex K, Annex L, Annex M, Annex N, Annex O, Annex ZB and Annex ZC;
c) alignment with Regulation (EU) 2016/426 on appliances burning gaseous fuels (GAR) and addition
of Annex ZB;
d) addition of the high-temperature operation (HTO).
Any feedback and questions on this document should be directed to the users’ national standards body.
A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organisations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia,
Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland,
Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of North
Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the United
Kingdom.
Introduction
This document is intended to be used in conjunction with EN 13611:2019.
This document refers to clauses of EN 13611:2019 or adapts clauses by stating “with the following
modification”, “with the following addition”, “is replaced by the following” or “is not applicable” in the
corresponding clause.
This document adds clauses or subclauses to the structure of EN 13611:2019 which are particular to this
document. Subclauses which are additional to those in EN 13611:2019 are numbered starting from 101.
Additional Annexes are designated as Annex AA, Annex BB, Annex CC, etc. It should be noted that these
clauses, subclauses and Annexes are not indicated as an addition.
If by reference to EN 13611:2019 the term “control” is given, this term should be read as automatic
burner control systems, flame detector devices or HTO detectors.
EN 298 compliance for automatic burner control systems, flame detector devices or HTO detectors
cannot be claimed based upon SIL classification according to the EN 61508 series.
SIL classification cannot be claimed based upon compliance with this standard only. A supplementary
method for SIL determination is specified in EN 13611:2019, Annex J.
1 Scope
EN 13611:2019, Clause 1 is replaced by the following:
This document specifies the safety, design, construction and performance requirements, and testing for
automatic burner control systems, programming units, flame detector devices and High Temperature
Operation (HTO) detectors, intended for use with gas and oil burners and gas and oil burning appliances,
with or without fans and similar use.
This document is applicable to automatic burner control systems that include additional functions.
This document is not applicable to automatic burner control systems utilizing thermo-electric flame
supervision devices.
NOTE Standards for burners, appliances or processes which use automatic burner control systems,
programming units, flame detectors or HTO detectors can override the requirements of this document.
2 Normative references
Shall be according to EN 13611:2019, Clause 2 with the following additions:
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
EN 267:2020, Forced draught burners for liquid fuels
EN 1643:2022, Safety and control devices for burners and appliances burning gaseous and/or liquid fuels
— Valve proving systems for automatic shut-off valves
EN 13611:2019 , Safety and control devices for burners and appliances burning gaseous and/or liquid fuels
— General requirements
EN 60730-1:2016 , Automatic electrical controls — Part 1: General requirements (IEC 60730-1:2013,
modified)
EN 60730-2-5:2015 , Automatic electrical controls — Part 2-5: Particular requirements for automatic
electrical burner control systems (IEC 60730-2-5:2013)
EN 60947-5-1:2017 , Low-voltage switchgear and controlgear — Part 5-1: Control circuit devices and
switching elements — Electromechanical control circuit devices (IEC 60947-5-1:2016, modified)
EN 61810-1:2015 , Electromechanical elementary relays — Part 1: General and safety requirements
(IEC 61810-1:2015)
EN ISO/IEC 80079-20-1:2019, Explosive atmospheres — Part 20-1: Material characteristics for gas and
vapour classification — Test methods and data (ISO/IEC 80079-20-1:2017, including Cor 1:2018)

As impacted by EN 13611:2019/AC:2021.
As impacted by EN 60730-1:2016/A1:2019 and EN 60730-1:2016/A2:2022.
As impacted by EN 60730-2-5:2015/A1:2019 and EN 60730-2-5:2015/A2:2021.
As impacted by EN 60947-5-1:2017/AC:2020-05.
As impacted by EN 61810-1:2015/AC:2017-07, EN 61810-1:2015/AC:2018-04 and EN 61810-1:2015/A1:2020.
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 13611:2019 apply with the
following modifications.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
• ISO Online browsing platform: available at https://www.iso.org/obp
• IEC Electropedia: available at https://www.electropedia.org/
3.23
safety shutdown
EN 13611:2019, 3.23 is replaced by 3.120
3.101
flame detector device
device by which the presence of a flame is detected and signalled
Note 1 to entry: Flame detector devices can consist of a flame sensor, an amplifier and a relay for signal
transmission. These parts, with the possible exception of the actual flame sensor, can be assembled in a single
housing for use in conjunction with a programming unit.
Note 2 to entry: Figure 1 contains an example of the composition of a flame detector device.

Key
1 automatic burner control system (see 3.110) 8 programming unit (see 3.109)
2 flame detector device (see 3.101) 9 shut-off valve (see 3.104)
3 flame 10 shut-off valve terminal
4 flame sensor (see 3.103) 11 flame signal (see 3.107)
5 amplifier 12 flame failure response time (see 3.105.1)
6 filter 13 sensed flame (see 3.106)
7 threshold
Figure 1 — Basic functional chain of a typical flame supervision
3.102
independent flame detector device
flame detector device which operates independent of the programming unit
Note 1 to entry: Self-checking functions are incorporated in this type of flame detector device.
Note 2 to entry: Figure 2 shows an example of the composition of a flame detector device.

Key
1 independent flame detector device (see 3.102) 6 threshold
2 flame 7 flame signal (see 3.107)
3 flame sensor (see 3.103) 8 flame failure detection time (see 3.105.2)
4 amplifier 9 sensed flame (see 3.106)
5 filter
Figure 2 — Basic functional chain of an independent flame detector device
3.103
flame sensor
device which reacts to the presence of the flame by providing an output signal that is used for further
signal processing
3.104
shut-off valve
safety device which releases the fuel flow when energized and stops the fuel flow automatically when de-
energized
Note 1 to entry: For further information refer to EN 161 or EN 126 for gas and EN ISO 23553-1 for oil, or to other
similar devices if mentioned in the relevant appliance standard.
3.105
flame failure response/detection time
3.105.1
flame failure response time
FFRT
response time between the loss of a sensed flame and the resulting de-energizing of the shut-off valve
terminals
Note 1 to entry: FFRT may be referred to as “extinction safety time” in appliance standards.
3.105.2
flame failure detection time
FFDT
response time of an independent flame detector device between the loss of a sensed flame and the flame
signal indicating the absence of a flame
3.106
sensed flame
physical value of the monitored flame
3.107
flame signal
signal given by the flame detector device in case of sensed flame
3.108
flame simulation
condition which occurs when the flame signal indicates the presence of a flame when in reality no flame
is present
3.109
programming unit
unit which executes the program, reacts to signals from control and safety devices, gives the control
commands, controls the start-up sequence, supervises the burner operation and causes controlled
shutdown, and if necessary, safety shutdown and lock-out
Note 1 to entry: The programming unit follows a predetermined sequence of actions and always operates in
conjunction with a flame detector device or HTO detector.
3.110
automatic burner control system
system comprising at least a programming unit and all the elements of a flame detector device or, if
applicable, HTO detector
Note 1 to entry: The various functions of an automatic burner control system can be in one or more housings.
3.111
start position
stage where the system is not in lock-out position and has not yet received the start signal but can proceed
with the start-up sequence when required
Note 1 to entry: At this stage, the output terminals for any shut-off valve and ignition device are not energized.
3.112
start signal
signal which releases the system from its start position and commences the predetermined program
Note 1 to entry: A thermostat is an example from which such a signal could be generated.
3.113
purge
forced introduction of air through the combustion chamber and flue passages in order to displace any
remaining fuel/air mixture and/or products of combustion
3.114
pre-purge
purge which takes place between the start signal and the energization of the shut-off valve or, in the case
of gas, the energization of the ignition device, if this comes first
3.115
post-purge
purge which takes place immediately following shutdown
3.116
first safety time
interval between the pilot shut-off valve, the start shut-off valve or the main shut-off valve, as applicable,
being energized and the pilot shut-off valve, start shut-off valve or the main shut-off valve, as applicable,
being de-energized if no flame signal is present
Note 1 to entry: Where there is no second safety time, this is called the safety time.
3.117
second safety time
where there is a first safety time applicable to either a pilot or start fuel flame only, the second safety time
is the interval between the main shut-off valve being energized and the main shut-off valve being de-
energized if no main flame signal is present
3.118
running position
position of the system in which the burner is in normal operation under the supervision of the
programming unit and its flame detector device or the burner is in HTO and supervised
3.119
controlled shutdown
process by which the power to the shut-off valve(s) is removed before any other action takes place as a
result of the action of a controlling function
3.120
safety shutdown
process which is effected immediately following the response of a protection device or the detection of a
fault in the automatic burner control system and puts the burner out of operation
Note 1 to entry: The resulting state of the system is defined by deactivated terminals for the shut-off valves and
the ignition device.
3.121
lock-out
3.121.1
non-volatile lock-out
safety shutdown condition of the control, where a restart can only be accomplished by a manual reset of
the control and by no other means
3.121.2
volatile lock-out
safety shutdown condition of the control, where a restart can only be accomplished by either a manual
reset of the control, or an interruption of the main power and its subsequent restoration
3.122
ignition restoration
spark restoration
process by which, following loss of flame signal, the ignition device is switched on again without total
interruption of the fuel supply
3.123
recycling
process by which, after a safety shutdown, a full start-up sequence is automatically repeated
3.124
timings
3.124.1
waiting time
for burners without fans, interval between the start signal being given and the energization of the
ignition device or shut-off valves, whichever comes first
Note 1 to entry: During this time natural ventilation of the combustion chamber and the flue passages can take
place.
3.124.2
waiting time
interval between the start signal being given (and air registers in purge position, if applicable) and
the energization of the ignition device
Note 1 to entry: During this time natural ventilation of the combustion chamber and the flue passages takes place.
3.124.3
pre-purge time
period during which purging takes place at the proven air rate prior to the energization of the
ignition device or shut-off valves, whichever comes first
3.124.4
pre-purge time
period preceding the signal to energize the shut-off valve during which the combustion chamber is
compulsorily ventilated
3.124.5
post-purge time
period during which purging takes place at the proven air rate between any shutdown and the
moment the fan is switched off
3.124.6
post-purge time
period following the signal to de-energize the shut-off valve during which the combustion chamber
is compulsorily ventilated
3.124.7
inter-purge time
period during which purging of the combustion chamber takes place at the proven air rate after
unsuccessful ignition and prior to the next recycle attempt
3.124.8
inter-waiting time
period during which natural ventilation of the combustion chamber takes place after unsuccessful
ignition and prior to the next recycle attempt
3.125
sequences
3.125.1
start-up sequence
sequence of actions executed by the system which brings the burner from the start position to the running
position
3.125.2
first stage
part of the start-up sequence which allows the release of start fuel into the combustion chamber
3.125.3
second stage
part of the start-up sequence which allows the release of further fuel into the combustion chamber
3.126
system for permanent operation
system that is designed to remain in the running position for longer than 24 h without interruption
3.127
system for non-permanent operation
system that is designed to remain in the running position for less than 24 h
3.128
self-checking function of the flame detector device/HTO detector
automatic internal function of the control which checks the operation of the flame detector device/HTO
detector
3.129
air flow simulation
condition which occurs when the air flow sensor indicates the presence of air flow when in reality no air
flow is present
3.130
spark supervision
process of monitoring the ignition spark
3.131
pilot or start fuel flame proving period
interval between the end of the first safety time and the beginning of the second safety time which is used
to prove that the pilot or start fuel flame is stable
3.132
intermittent first stage
first stage that is ignited prior to ignition of the main flame and is shut off simultaneously with the main
flame
3.133
interrupted first stage
first stage that is ignited each time the burner is started up and which is extinguished at the end of the
second safety time
3.134
burner ignition systems
3.134.1
ignition by supervised gas-fired pilot burner
system which releases the main fuel when the ignition burner flame is present
3.134.2
ignition by non-supervised gas-fired pilot burner
system in which the release of the main fuel is not prevented by the absence of the flame of the pilot
burner
3.135
ignition timings
3.135.1
total ignition time
period during which the ignition device is energized
Note 1 to entry: This time includes pre-ignition, ignition and post-ignition times.
3.135.2
pre-ignition time
period between the energization of the ignition device and the start of the safety time
3.135.3
ignition time
period between the start of the safety time and the first detection of a flame signal
Note 1 to entry: The maximum ignition time ends prior to or simultaneous with the safety time when no flame
signal has been detected.
3.135.4
post-ignition time
period between the first detection of the flame signal and the de-energization of the ignition device
3.136
maximum fuel flow rate
constant mass of oil consumed during a period of time at maximum heat input as stated in the instructions
Note 1 to entry: Maximum fuel flow rate is expressed in kilograms per hour (kg/h).
[SOURCE: EN 267:2020, 3.2.1.1]
3.137
common cause failure
failure of different items, resulting from a single event, where these failures are not consequences of each
other
Note 1 to entry: Common cause failures should not be confused with common mode failures.
[SOURCE: IEV 191-04-23]
3.138
high-temperature operation
HTO
operation on the basis of auto-ignition temperature which assures ignition and burning of fuel
Note 1 to entry: High-temperature operation is used e.g. in fuel cells (EN IEC 62282-3-100) and in industrial
furnaces and associated processing equipment (EN 746-2) where ignition and burning is detected by means of
sensing the temperature.
3.139
HTO detector
device which provides the programming unit with a signal indicating presence or absence of HTO
Note 1 to entry: It includes the HTO sensor and may include an amplifier and a relay for signal transmission. The
amplifier and relay may be in its own housing or combined with the programming unit.
Note 2 to entry: Figure 3 shows an example of the basic functional chain of a typical HTO detector supervision

Key
1 automatic burner control system (see 3.110) 8 programming unit (see 3.109)
2 HTO detector (see 3.139) 9 shut-off valve (see 3.104)
3 flame 10 shut-off valve terminal
4 HTO sensor (see 3.140) 11 HTO signal (see 3.144)
5 amplifier 12 HTO detector response time (see 3.142)
6 filter 13 sensed flame (see 3.106)
7 threshold
Figure 3 — Basic functional chain of a typical HTO detector supervision
3.140
HTO sensor
device which senses the temperature of a surface or a medium within the combustion chamber which is
in direct contact with a flammable fuel-air mixture and provides a signal indicating presence or absence
of HTO
3.141
auto-ignition temperature
AIT
lowest temperature (of a hot surface or the environment) at which an ignition of a flammable fuel/air
mixture occurs
[SOURCE: EN ISO/IEC 80079-20-1:2019, 3.3, modified: “or the environment” has been added in the
parenthesis, “at which under specified test conditions” has been deleted and “ flammable gas or vapour
in mixture with air or air/inert gas” has been replaced by “ flammable fuel/air mixture”]
3.142
HTO detector response time
period of time between the temperature falling below the defined HTO temperature limit and the control
proceeding to safety shutdown or to switch over to flame supervision
3.143
HTO detector operating characteristics
function of the HTO detector which indicates absence or presence of HTO as the output signal of the HTO
detector relating to the input signal
Note 1 to entry: Normally the input signal is provided by a HTO sensor.
3.144
HTO signal
output signal of the HTO detector
3.145
independent HTO detector
HTO detector which operates independent of the programming unit
Note 1 to entry: Self-checking functions are incorporated in this type of HTO detector.
Note 2 to entry: Figure 4 shows an example of the basic functional chain of an independent HTO detector.
Key
1 independent HTO detector (see 3.145) 6 threshold
2 flame 7 HTO signal (see 3.144)
3 HTO sensor (see 3.140) 8 HTO detection time (see 3.146)
4 amplifier 9 sensed flame (see 3.106)
5 filter
Figure 4 — Basic functional chain of an independent HTO detector
3.146
HTO detection time
period of time of an independent HTO detector between the loss of a sensed flame and the HTO signal
indicating the absence of a flame
4 Classification
4.1 Classes of control
EN 13611:2019, 4.1 is replaced by the following:
This document does not provide classes of controls.
4.2 Groups of control
EN 13611:2019, 4.2 is not applicable.
4.3 Classes of control functions
Shall be according to EN 13611:2019, 4.3 with the following addition:
— the burner control system is a class C control function;
— the flame detector device or HTO detector (including sensor and detector), if independent from the
programming unit, is a class C control function;
— the reset function as given in 6.6.1.3 is a class B control function.
4.4 Types of DC supplied controls
Shall be according to EN 13611:2019, 4.4.
5 Test conditions and uncertainty of measurements
Shall be according to EN 13611:2019, Clause 5.
6 Design and construction
6.1 General
Shall be according to EN 13611:2019, 6.1.
6.2 Mechanical parts of the control
EN 13611:2019, 6.2 is not applicable.
6.3 Materials
EN 13611:2019, 6.3 is not applicable.
6.4 Gas connections
EN 13611:2019, 6.4 is not applicable.
6.5 Electrical parts of the control
6.5.1 General
Shall be according to EN 13611:2019, 6.5.1.
6.5.2 Switching elements
6.5.2.1 Requirements
Shall be according to EN 13611:2019, 6.5.2.1 with the following addition:
The requirement to include at least two operating elements does not apply to flame detector devices or
HTO detectors which are not intended to energize shut-off valves directly.
The requirement for two independent operating elements can be replaced by a requirement for one
operating element for each shut-off valve (two operating elements in total), under the following
conditions which guarantee the same overall safety level:
— an integrated solution consisting of a burner control function and a valve-proving system according
to EN 1643:2022 and
— the valve proving system checking the leakage during each burner cycle.
The above requirement does not supersede the other requirements of this document e.g. fault
assessment.
The construction of any additional functions included in the automatic burner control system,
programming unit, flame detector device or HTO detector, for which no provisions exist in this standard,
shall be such that they do not degrade the safe and correct operation of the automatic burner control
system, programming unit flame detector device, or HTO detector.
Measures shall be taken to protect against the failure of two (or more) switching elements, due to a
common cause by an external short-circuit that would prevent the automatic burner control system from
performing a safety shutdown.
Acceptable methods are current limitation, overcurrent protection device or internal fault detecting
functions.
The suitability of measures to maintain the capability to interrupt the energization of the shut-off valve
terminals by means of at least one switching element, or by interrupting a non-replaceable overcurrent
protection device, shall be verified by the following test.
6.5.2.2 Test of protecting measures against failure of switching elements
Shall be according to EN 13611:2019, 6.5.2.2 with the following modifications:
For the purpose of this clause, the terms “safety related output terminals” or “output terminals” are
replaced by “shut-off valve terminals”
Delete in the brackets of the first paragraph the words “contacts of”.
Add the following NOTE:
NOTE A switching element means semiconductors as well as electro-mechanic switching elements.
Add to the end of the 2nd paragraph the following text:
If the valve circuit of the burner control system is always supplied by an integrated power supply, the
test shall be applied with this integrated power supply under worst-case conditions for the highest short
circuit current.
6.5.3 Electrical components
6.5.3.1 Performance of electrical components
Shall be according to EN 13611:2019, 6.5.3.1.
6.5.3.2 Tests
Shall be according to EN 13611:2019, 6.5.3.2.
6.5.3.3 Sensing element
Shall be according to EN 13611:2019, 6.5.3.3 for HTO sensors.
6.5.3.4 Gas controls employing electrical components in the gas circuit
EN 13611:2019, 6.5.3.4 is not applicable.
6.6 Protection against internal faults for the purpose of functional safety
6.6.1 Design and construction requirements
6.6.1.1 Fault avoidance and fault tolerance
Shall be according to EN 13611:2019, 6.6.1.1.
6.6.1.2 Lock-out function
Shall be according to EN 13611:2019, 6.6.1.2.
6.6.1.3 Reset device
Shall be according to EN 13611:2019, 6.6.1.3 with the following addition:
— the switching action of a thermostat or similar devices can result in a reset from volatile lock-out (see
10.2 o));
— the requirements for a reset device shall be evaluated together with the reset function as functional
part of an automatic burner control system.
6.6.1.4 Design documentation
Shall be according to EN 13611:2019, 6.6.1.4.
6.6.2 Class A
EN 13611:2019, 6.6.2 is not applicable.
6.6.3 Class B
Shall be according to EN 13611:2019, 6.6.3.
The reset function as given in 6.6.1.3 is a class B control function, see Annex M.
6.6.4 Class C
6.6.4.1 Design and construction requirements
Shall be according to EN 13611:2019, 6.6.4.1 with the following modification:
Replace the last paragraph by the following:
Automatic burner control systems, independent flame detector devices and HTO detectors shall be fail-
safe. Controls which meet the requirements of this clause and, if applicable, 6.6.1.1, are considered to be
inherently fail-safe.
The circuitry and the construction of the control shall be such that they meet the requirements of 7.101.
They shall be appraised according to the requirements of 6.6.4.2, 6.6.4.3 and 6.6.4.4, and tested under the
test conditions and criteria of 6.6.5.
Components shall be dimensioned on the basis of the worst-case conditions which can arise in the control,
as stated in the instructions.
Internal faults of the checking circuit for discharge tubes used in flame detector devices for non-
permanent operation (see 7.101.4.1.5) shall not be considered.
6.6.4.2 First fault
EN 13611:2019, 6.6.4.2 is replaced by the following:
Any first fault (see Annex E) in any one component, or any one fault together with any other fault arising
from that first fault, shall result in either:
a) the control becoming inoperative with all shut-off valve terminals de-energized (for independent
flame detector devices or independent HTO detectors the de-energization of the flame signal output
resulting in a “flame off” signal is equivalent);
b) the control proceeding to safety shutdown within 3 s, or to lock-out, provided that subsequent reset
from the lock-out condition under the same fault condition results in the control returning to the
lock-out condition; continue with fault assessment during lock-out or safety shutdown according to
6.6.4.4.3;
c) the control continuing to operate, the fault being identified during the next start-up sequence and
the result being either a) or b);
d) the control remaining operational in accordance with all other functional requirements of this
standard (see 7.101.2 to 7.101.5).
For automatic burner control systems, independent flame detector devices and HTO detectors designed
for non-permanent operation, list item c) is applicable. List item c) is not applicable for automatic burner
control systems, independent flame detector devices and HTO detectors designed for permanent
operation.
6.6.4.3 Second fault
Shall be according to EN 13611:2019, 6.6.4.3 with the following addition:
For automatic burner control systems, independent flame detector devices and HTO detectors designed
for non-permanent operation EN 13611:2019, 6.6.4.3 a) is applicable. EN 13611:2019, 6.6.4.3 b) is
applicable for automatic burner control systems, independent flame detector devices and HTO detectors
designed for permanent operation.
NOTE While conducting this test, the fault can be applied at any time. It is not necessary to wait 24 h before
applying the fault. If the fault was applied before 24 h and unacceptable results were obtained, the fault is applied
24 h after the first fault.
6.6.4.4 Faults during lock-out or safety shutdown
6.6.4.4.1 General
Shall be according to EN 13611:2019, 6.6.4.4.1.
6.6.4.4.2 First fault introduced during lock-out or safety shutdown
EN 13611:2019, 6.6.4.4.2 is replaced by the following:
During assessment, the first fault shall not be reckoned to occur within 24 h after lock-out or safety
shutdown is reached, without an internal fault.
Any first fault (together with any other fault arising from that fault) in any one component (see Anne
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