oSIST prEN 12067-2:2016

Safety and control devices for burners and appliances burning gaseous or liquid fuels - Control functions in electronic systems - Part 2: Fuel/air ratio control / supervision of the electronic type

This European Standard specifies the safety, construction and performance requirements for electronic fuel/air ratio control (ERC), electronic fuel/air ratio supervision (ERS) and electronic fuel/air ratio trim (ERT) intended for use with burners and appliances burning gaseous or liquid fuels. It also describes the test procedures for evaluating these requirements and specifies information necessary for installation and use.
This standard is applicable to
-   closed loop fuel/air ratio controls (see 3.101),
-   fuel/air ratio supervision systems (see 3.102),
-   closed loop fuel/air ratio trim systems (see 3.103) and does not differentiate into classification by heat input.
This standard applies to ERC, ERS or ERT that can be tested independently, as well as part of an appliance or a burner.
NOTE 1 European Standards for burners, appliances or processes which use ERC, ERS or ERT can override the requirements of this standard.
NOTE 2 Provisions for production control are not part of this European Standard.

Sicherheits- und Regeleinrichtungen für Brenner und Brennstoffgeräte für gasförmige oder flüssige Brennstoffe - Regel- und Steuerfunktionen in elektronischen Systemen - Teil 2: Elektronische Gas-Luft-Verbundregel- und überwachungseinrichtungen

EN 13611:2015, Abschnitt 1, ist durch Folgendes zu ersetzen:
Diese Europäische Norm legt die Sicherheits , Konstruktions  und Leistungsanforderungen für elektronische Brennstoff Luft Verbundregeleinrichtungen (ERC, en: electronic fuel/air ratio control), elektronische Brennstoff Luft Verbundüberwachungseinrichtungen (ERS, en: electronic fuel/air ratio supervision) und elektronische Brennstoff Luft Verbundtrimmsteuerungen (ERT, en: electronic fuel/air ratio trim) für Brenner und Brennstoffgeräte für gasförmige oder flüssige Brennstoffe fest. Darüber hinaus beschreibt sie die Prüfverfahren zur Bewertung dieser Anforderungen und legt die für Einbau und Betrieb erforderlichen Angaben fest.
Diese Europäische Norm gilt für:
—   Brennstoff Luft Verbundregeleinrichtungen mit geschlossenem Regelkreis, siehe 3.101;
—   Brennstoff Luft Verbundüberwachungssysteme, siehe 3.102;
—   Brennstoff Luft Verbundtrimmsysteme mit geschlossenem Regelkreis, siehe 3.103,
und unterscheidet bei der Klassifizierung nicht nach Wärmebelastung.
Diese Europäische Norm gilt für ERC, ERS oder ERT, die sowohl unabhängig als auch als Teil eines Brennstoffgerätes oder Brenners geprüft werden können.
ANMERKUNG 1   Europäische Normen für Brenner, Brennstoffgeräte oder Prozesse, die ERC, ERS oder ERT einsetzen, können die Anforderungen dieser Norm außer Kraft setzen.
ANMERKUNG 2   Festlegungen für die Produktionskontrolle sind nicht Gegenstand dieser Europäischen Norm.

Dispositifs de commande et de sécurité pour les brûleurs et les appareils à gaz ou fioul - Dispositifs électroniques de régulation - Partie 2 rév : Régulation et surveillance du rapport air/combustible de type électronique

L'article 1 de l'EN 13611:2015 doit être remplacé par :
La présente Norme européenne spécifie les exigences de sécurité, de construction et de performance pour le régulateur électronique du rapport air/combustible (ERC), la surveillance électronique du rapport air/combustible (ERS) et le contrôle électronique du rapport air/combustible (ERT) destinés à équiper les brûleurs et appareils à gaz ou fioul. Elle décrit aussi les modes opératoires d’essai permettant de vérifier la conformité à ces exigences, ainsi que les informations nécessaires à l’installation et à l’utilisation.
La présente Norme est applicable :
   aux dispositifs de régulation du rapport air/combustible en boucle fermée, voir 3.101 ;
   aux systèmes de surveillance du rapport air/combustible, voir 3.102 ;
   aux systèmes de contrôle du rapport air/combustible en boucle fermée, voir 3.103 ;
et ne fait pas de classification en fonction du débit calorifique.
La présente Norme s’applique aux ERC, ERS ou ERT qui peuvent être soumis à essai séparément, comme à ceux faisant partie d’un appareil ou d’un brûleur.
NOTE 1   Les Normes européennes pour les brûleurs, appareils ou processus qui utilisent l'ERC, l'ERS ou l'ERT peuvent annuler les exigences de la présente norme.
NOTE 2   Les dispositions de contrôle de la production ne font pas partie de la présente Norme européenne.

Varnostne in nadzorne naprave za gorilnike in aparate na plin ali tekoča goriva - Regulacijske in nadzorne funkcije v elektronskih sistemih - 2. del: Regulacija in nadzor razmerja goriva in zraka za elektronski tip

General Information

• Status: Not Published
• Public Enquiry End Date: 01-Feb-2016
• ICS: 23.060.40 - Pressure regulators
• ICS: 27.060.01 - Burners and boilers in general
• Technical Committee: PLN - Gas appliances for domestic use
• Current Stage: 98 - Abandoned project (Adopted Project)
• Start Date: 15-May-2019
• Due Date: 20-May-2019
• Completion Date: 15-May-2019
• Directive: 2009/142/EC - DIRECTIVE 2009/142/EC OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL of 30 November 2009 relating to appliances burning gaseous fuels
• Mandate: M/BC/CEN/89/6 - Standardization request to CEN concerning appliances burning gaseous fuels
• Ref Project: prEN 12067-2 rev - Safety and control devices for burners and appliances burning gaseous or liquid fuels - Control functions in electronic systems - Part 2: Fuel/air ratio control / supervision of the electronic type

Relations

• Revised: SIST EN 12067-2:2023 - Safety and control devices for burners and appliances burning gaseous or liquid fuels - Control functions in electronic systems - Part 2: Fuel/air ratio control/supervision of the electronic types
• Effective Date: 01-Feb-2023
• Revised: SIST EN 12067-2:2004 - Gas/air ratio controls for gas burners and gas burning appliances - Part 2: Electronic types
• Effective Date: 18-Jan-2023
• Revised: SIST EN 12067-2:2004 - Gas/air ratio controls for gas burners and gas burning appliances - Part 2: Electronic types
• Effective Date: 01-Jan-2016

Overview

prEN 12067-2 rev (CEN) defines safety, construction and performance requirements for electronic fuel/air ratio control systems used with burners and appliances burning gaseous or liquid fuels. The standard covers three device types: Electronic Fuel/Air Ratio Control (ERC), Electronic Fuel/Air Ratio Supervision (ERS) and Electronic Fuel/Air Ratio Trim (ERT). It specifies test procedures, required information for installation and use, and applies to controls that can be tested independently or as part of an appliance. Note: provisions for production control are not included.

Key topics and technical requirements

• Scope and applicability
  • Applies to closed-loop fuel/air ratio controls, supervision systems and trim systems regardless of heat input.
  • Can be used for stand-alone controls or integrated in burners/appliances.
• Design and construction
  • Mechanical and electronic design requirements, materials for pressurized parts, gas connections, and electromechanical actuators with position feedback.
  • Protection against internal faults to meet functional safety needs (different protection classes).
• Performance and testing
  • Leak-tightness (volumetric and pressure-loss methods), rated flow, torsion/bending and durability tests.
  • Long-term and stress tests, ambient/min/max temperature performance checks and data-exchange requirements.
• Functional and electrical
  • Interface requirements to automatic burner control systems, ranges of operation, restart-from-safe-state behavior and accuracy requirements for fuel/air ratio control.
  • Electrical requirements including enclosure protection, EMC and immunity to supply variations, surges, RF fields, ESD and harmonics.
• Safety integrity and diagnostics
  • Methods for determining Safety Integrity Level (SIL) and Performance Level (PL), reset functions and fault mode evaluation.
• Documentation and marking
  • Mandatory marking, installation and operating instructions, warning notices and technical information for safe integration in appliances.
• Supporting annexes
  • Normative and informative annexes provide test methods, materials guidance, integration guidelines and relationships to EU directives.

Applications and who uses it

This standard is essential for:

• Manufacturers of burners, boilers and heating appliances using gaseous or liquid fuels.
• OEM designers integrating electronic fuel/air ratio control (ERC/ERS/ERT) into systems.
• Safety and control engineers specifying functional safety, EMC and performance tests.
• Test laboratories, certification bodies and compliance teams verifying conformity to CEN requirements.
• Installers and maintenance personnel who rely on the standard’s installation and operating instructions.

Related standards

• prEN 12067-2 rev complements other parts of the EN 12067 series and references EU directives (e.g., appliance safety and pressure equipment). It is intended to align with CEN/CENELEC internal regulations and may supersede EN 12067-2:2004 where applicable.

Keywords: fuel/air ratio control, ERC, ERS, ERT, electronic control, burners, appliances burning gaseous or liquid fuels, prEN 12067-2 rev, CEN, functional safety, EMC.

Standards Content (Sample)

SLOVENSKI STANDARD
01-januar-2016
9DUQRVWQHLQQDG]RUQHQDSUDYH]DJRULOQLNHLQDSDUDWHQDSOLQDOLWHNRþDJRULYD
.UPLOQHLQQDG]RUQHIXQNFLMHYHOHNWURQVNLKVLVWHPLKGHO5HJXODFLMDLQQDG]RU
UD]PHUMDJRULYDLQ]UDND]DHOHNWURQVNLWLS
Safety and control devices for burners and appliances burning gaseous or liquid fuels -
Control functions in electronic systems - Part 2: Fuel/air ratio control / supervision of the
electronic type
Sicherheits- und Regeleinrichtungen für Brenner und Brennstoffgeräte für gasförmige
oder flüssige Brennstoffe - Regel- und Steuerfunktionen in elektronischen Systemen -
Teil 2: Elektronische Gas-Luft-Verbundregel- und überwachungseinrichtungen
Dispositifs de commande et de sécurité pour les brûleurs et les appareils à gaz ou fioul -
Dispositifs électroniques de régulation - Partie 2 rév : Régulation et surveillance du
rapport air/combustible de type électronique
Ta slovenski standard je istoveten z: prEN 12067-2 rev
ICS:
23.060.40 7ODþQLUHJXODWRUML Pressure regulators
27.060.01 Gorilniki in grelniki vode na Burners and boilers in
splošno general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
EUROPEAN STANDARD
prEN 12067-2
NORME EUROPÉENNE
EUROPÄISCHE NORM
November 2015
ICS 23.060.40; 27.060.20 Will supersede EN 12067-2:2004
English Version
Safety and control devices for burners and appliances
burning gaseous or liquid fuels - Control functions in
electronic systems - Part 2: Fuel/air ratio control /
supervision of the electronic type
Dispositifs de commande et de sécurité pour les Sicherheits- und Regeleinrichtungen für Brenner und
brûleurs et les appareils à gaz ou fioul - Dispositifs Brennstoffgeräte für gasförmige oder flüssige
électroniques de régulation - Partie 2 rév : Régulation Brennstoffe - Regel- und Steuerfunktionen in
et surveillance du rapport air/combustible de type elektronischen Systemen - Teil 2: Elektronische Gas-
électronique Luft-Verbundregel- und überwachungseinrichtungen
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 58.
If this draft becomes a European Standard, 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.

This draft European Standard was established by CEN 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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are
aware and to provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without
notice and shall not be referred to as a European Standard.

EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2015 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 12067-2:2015 E
worldwide for CEN national Members.

prEN 12067-2:2015 (E)
Contents Page
European foreword . 6
Introduction . 7
1 Scope . 8
2 Normative references . 8
3 Terms and definitions . 8
4 Classification . 14
4.1 Classes of control . 14
4.2 Groups of control . 14
4.3 Classes of control functions . 14
4.4 Types of DC supplied controls . 14
5 Test conditions and uncertainty of measurements . 14
6 Design and construction . 14
6.1 General . 14
6.1.101 General structure and feedback types . 14
6.2 Mechanical parts of the control . 15
6.2.101 Use of non-metallic material . 15
6.2.102 Special requirements for electromechanical actuators with position feed-back
sensors . 15
6.3 Materials . 16
6.4 Gas connections . 16
6.5 Electronic parts of the control . 16
6.5.1 General . 16
6.5.2 Switching elements . 16
6.5.3 Electrical components . 16
6.6 Protection against internal faults for the purpose of functional safety . 16
6.6.1 Design and construction requirements . 16
6.6.2 Class A . 16
6.6.3 Class B . 16
6.6.4 Class C . 17
6.6.5 Circuit and construction evaluation . 18
7 Performance . 18
7.1 General . 18
7.2 Leak-tightness . 18
7.3 Torsion and bending . 18
7.4 Rated flow rate . 18
7.5 Durability . 18
7.6 Performance tests for electronic controls . 18
7.6.1 At ambient temperature . 18
7.6.2 At minimum temperature . 18
7.6.3 At maximum temperature . 18
7.7 Long-term performance for electronic controls . 19
7.7.1 General . 19
7.7.1.101 Test requirements . 19
7.7.1.102 Test conditions . 19
prEN 12067-2:2015 (E)
7.7.2 Stress test . 20
7.7.3 Long term performance test . 20
7.8 Data exchange . 20
7.101 Functional requirements . 20
7.101.1 General . 20
7.101.2 Interface to the automatic burner control system . 21
7.101.3 Void . 21
7.101.4 Ranges of operation . 21
7.101.5 Restart from safe state . 22
7.101.6 Accuracy requirements . 23
8 Electrical requirements . 23
8.1 General . 23
8.2 Protection by enclosure . 23
9 Electromagnetic compatibility (EMC) . 23
9.1 Protection against environmental influences . 23
9.2 Supply voltage variations below 85 % of rated voltage. 24
9.3 Voltage dips and interruptions . 24
9.4 Supply frequency variations . 24
9.5 Surge immunity test . 24
9.6 Electrical fast transient/burst . 25
9.7 Immunity to conducted disturbances induced by radio frequency fields . 25
9.8 Immunity to radiated fields induced by radio frequency fields . 25
9.9 Electrostatic discharge test . 25
9.10 Power frequency magnetic field immunity test . 26
9.11 Harmonics and interharmonics including mains signalling at a. c. power port, low
frequency immunity tests . 26

10 Marking, installation and operating instructions . 26
10.1 Marking . 26
10.2 Installation and operating instructions . 26
10.3 Warning Notice . 28
10.101 Technical information for the safety after integration in the appliance . 28
Annex A (informative) Abbreviations and Symbols . 29
Annex B (informative) Leak-tightness test for gas controls − Volumetric method . 30
Annex C (informative) Leak-tightness for gas controls − Pressure loss method . 31
Annex D (normative) Calculation of pressure loss into leakage rate . 32
Annex E (normative) Electrical/electronic component fault modes . 33
Annex F (normative) Additional requirements for safety accessories and pressure
accessories as defined in EU 97/23/EC. 34
Annex G (normative) Materials for pressurized parts . 35
Annex H (informative) Additional materials for pressurized parts . 36
Annex I (normative) Requirements for controls used in DC supplied burners and
appliances burning gaseous or liquid fuels. 37
Annex J (normative) Method for the determination of a Safety integrity level (SIL) . 38
Annex K (normative) Method for the determination of a Performance Level (PL) . 39
Annex L (informative) Relationship between Safety Integrity Level (SIL) and Performance
Level (PL) . 40
prEN 12067-2:2015 (E)
Annex M (normative) Reset functions . 41
Annex N (informative) Guidance document on Environmental Aspects . 42
Annex O (normative) Seals of elastomer, cork and synthetic fibre mixtures. 43
Annex AA (normative) Declaration for sensors, actuators and repeatability . 44
Annex BB (normative) Special requirements for single position feed-back potentiometers
in electromechanical actuators . 48
Annex CC (informative) Overall fuel to air ratio accuracy . 49
Annex DD (informative) Guideline for the integration of an ERC, ERS or ERT into the
appliance . 50
Annex EE (informative) Guideline for the definition of limits for safe operation of the
appliance . 52
Annex ZA (informative) Relationship between this European Standard and the Essential
Requirements of EU Directive 2009/142/EC relating to appliances burning gaseous
fuels . 58
Annex ZB (informative) Relationship between this European Standard and the Essential
Requirements of EU Directive 97/23/EC concerning pressure equipment . 60
Bibliography . 61
Figure
Figure 1 — Scope of the electronic fuel/air ratio control (ERC) . 9
Figure 2 — Scope of the electronic fuel/air ratio supervision (ERS) . 10
Figure 3 — Scope of the electronic fuel/air ratio trim (ERT) . 11
Figure 4 — Fault tolerating time (FTT) . 12
Figure 5 — Fault reaction time control for ERC and ERS . 12
Figure 6 — Fault reaction time control for ERT . 13
Figure 7 — Fault reaction time control for ERC and ERS . 22
Offset Figure AA.1 — Informative graph for definitions . 44
Figure EE.1 — Maximum permissible concentration of combustible substances [from EN 1539] . 54
Figure EE.2 — Test room dimensions . 56
Table
Table 1 — Acceptable feedback types . 15
Table AA.1 — Declaration for sensors . 45
Table AA.2 — Declaration for actuators . 46
Table AA.3 — Declaration for accuracy . 47
Table CC.1 — Tolerances . 49
prEN 12067-2:2015 (E)
Table DD.1 — Responsibility matrix . 51
Table EE.1 — Example of lower explosion limits (LEL) and ignition temperatures for different
combustibles. . 53
Table EE.2 — Maximum leakage rate (Source: EN 15502-2-1: Table 102 Maximum admissible leakage
rates) . 57
Table ZA.1 — Correspondence between this European Standard and Directive 2009/142/EC relating to
appliances burning gaseous fuels . 58

prEN 12067-2:2015 (E)
European foreword
This document (prEN 12067-2:2015) 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 document is currently submitted to the CEN Enquiry.
This document will supersede EN 12067-2:2004.
This document has been prepared under a mandate given to CEN by the European Commission and the
European Free Trade Association, and supports essential requirements of EU Directives.
For relationship with EU Directives, see informative Annexes ZA and ZB, which are integral parts of this
document.
It should be noted that the following significant changes compared to the previous edition have been
incorporated in this European Standard:
a) alignment with EN 13611:2015;
b) integration of the requirements for fuel to air ratio using oil as the fuel;
c) addition of the control types ERS and ERT and
d) updating to IEC 60730-1:2013;
e) update requirements for fault reaction time and fault tolerating time;
f) updating the Annexes for Sensors and actors;
g) including the use of pressure sensing devices already complying with EN 1854;
h) new Annex “Guideline for the integration of ERC, ERS or ERT into the appliances;
i) new Annex “Guideline for the definition of limits for safe operation on the appliance.
prEN 12067-2:2015 (E)
Introduction
This standard recognizes the safety level specified by CEN/TC 58 dealing with the safety, construction
and performance of controls for burners and appliances burning gaseous or liquid fuels and to their
testing.
This document refers to clauses of EN 13611:2015-07 and adapts them, indicating the changes by
stating "with the following modification", "with the following addition", "is replaced by the following" or
"is not applicable". It also adds clauses or sub-clauses to the structure of EN 13611:2015-07 which are
particular to this standard (prEN 12067-2:2015). Additional sub-clauses or annexes are either
numbered starting from 101 or are designated as Annex AA, BB, CC etc. It should be noted however that
these clauses and sub-clauses are not indicated as additions in the text.
EN 12067-2 compliance for electronic fuel/air ratio control cannot be claimed based upon SIL
classification according to EN 61508.
SIL classification cannot be claimed based upon compliance with this standard only. A supplementary
method for SIL determination is specified in EN 13611:2015, Annex J.
prEN 12067-2:2015 (E)
1 Scope
EN 13611:2015, 1 shall be replaced by the following:
This European Standard specifies the safety, construction and performance requirements for electronic
fuel/air ratio control (ERC), electronic fuel/air ratio supervision (ERS) and electronic fuel/air ratio trim
(ERT) intended for use with burners and appliances burning gaseous or liquid fuels. It also describes
the test procedures for evaluating these requirements and specifies information necessary for
installation and use.
This European Standard is applicable to
— closed loop fuel/air ratio controls, see 3.101;
— fuel/air ratio supervision systems, see 3.102;
— closed loop fuel/air ratio trim systems, see 3.103;
and does not differentiate into classification by heat input.
This European Standard applies to ERC, ERS or ERT that can be tested independently, as well as part of
an appliance or a burner.
NOTE 1 European Standards for burners, appliances or processes which use ERC, ERS or ERT can override the
requirements of this standard.
NOTE 2 Provisions for production control are not part of this European Standard.
2 Normative references
The following referenced documents are indispensable for the application 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 88-1:2011, Pressure regulators and associated safety devices for gas appliances — Part 1: Pressure
regulators for inlet pressures up to and including 50 kPa;
EN 298:2012, Automatic burner control systems for burners and appliances burning gaseous or liquid
fuels
EN 16340:2014, Safety and control devices for burners and appliances burning gaseous or liquid fuels —
Combustion product sensing devices
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 13611:2015 and the following
apply.
3.101
electronic fuel/air ratio control (ERC)
closed loop modulating system consisting of the electronic control, actuating elements for the fuel flow
and the air flow as a minimum, and allocated feedback signal(s)
Note 1 to entry: Figure 1 shows an example of different feedback alternatives. For details, see also Table 1.
prEN 12067-2:2015 (E)
Key
1 electronic control unit (ECU) 8 sensor flame
2 combustion process 9 sensor flue gas
3 actuator air 10 actuator air feedback
4 actuator fuel 11 actuator fuel feedback
5 sensor air 12 automatic burner control system
6 sensor fuel
7 sensor fuel air mixture scope of ERC
Figure 1 — Scope of the electronic fuel/air ratio control (ERC)
3.102
electronic fuel/air ratio supervision (ERS)
supervision system consisting of electronic and sensor(s), providing at least one output signal to
indicate if the combustion process is in safe state or not
Note 1 to entry: Figure 2 shows an example of different feedback alternatives. For details, see also Table 1.
prEN 12067-2:2015 (E)
Key
1 electronic control unit (ECU) 8 sensor flame
2 combustion process 9 sensor flue gas
3 actuator air 10 actuator air feedback
4 actuator fuel 11 actuator fuel feedback
5 sensor air 12 automatic burner control system
6 sensor fuel 13 arbitrary control
7 sensor fuel air mixture
scope of ERC
Figure 2 — Scope of the electronic fuel/air ratio supervision (ERS)
3.103
electronic fuel/air ratio trim (ERT)
closed loop system consisting of the electronic trim control, actuating element(s) or control output to
influence the fuel air ratio controlled by other means and the allocated feedback signal(s)
Note 1 to entry: Figure 3 shows an example of different feedback alternatives. For details, see also Table 1.
prEN 12067-2:2015 (E)
Key
1 electronic control unit (ECU) 9 sensor flue gas
2 combustion process 10 actuator air feedback
3 actuator air 11 actuator fuel feedback
4 actuator fuel 12 automatic burner control system
5 sensor air 13 arbitrary control
6 sensor fuel 14 trimsignal air
7 sensor fuel air mixture 15 trimsignal fuel
8 sensor flame
scope of ERC
Figure 3 — Scope of the electronic fuel/air ratio trim (ERT)
3.104
electronic control unit (ECU)
electronic main control module incorporating all inputs and outputs for the ERC, ERS or ERT function
3.105
actuator
device for controlling the amount of fuel and/or air
3.106
sensor
device which gives a signal related to a physical property to which it responds
3.107
combustion process
chemical reaction between fuel and air to produce heat
3.108
safe state
state of the system with the following characteristics:
a) the system passively assumes a state in which the output signal(s) ensure a safe situation under all
circumstances or;
prEN 12067-2:2015 (E)
b) the system actively executes a protective action causing it to shut down and lock out, or;
c) the system remains in operation, continuing to satisfy all safety related functional requirements
3.109
fault tolerating time (FTT)
time between the occurrence of a fault and reaching a safe state, which is tolerated by the application
without resulting in a hazardous situation
Note 1 to entry: For illustration of the fault tolerating time, see Figure 4.

Figure 4 — Fault tolerating time (FTT)
3.110
Fault reaction time control (FRTc)
time that the ERC, ERS or ERT needs from the moment the fault condition reaches the sensor to the
moment of an initialisation to reach a safe state
Note 1 to entry: For illustration of the fault reaction time control for ERC and ERS, see Figure 5.

Key
1. fuel air ratio is outside the safe area of the application 5. filter
2. delay time till fault condition reaches the sensor 6. limit switch
3. sensor monitoring fuel/air ratio e.g. position sensors, flue gas sensors 7. automatic burner control
4. amplifier 8. shut down valve
Figure 5 — Fault reaction time control for ERC and ERS
Note 2 to entry: For illustration of the fault reaction time control for ERT, see Figure 6.
prEN 12067-2:2015 (E)
Key
1. Fuel air ratio is outside the safe area of the application 5. Filter
2. Delay time till condition reaching the sensor 6. Limit switch
3. Sensor monitoring fuel/air ratio e.g. position sensors, 7. Fuel/air ratio control (an ERC may be part of
flue gas sensors the system)
4. Amplifier 8. (Trimming) actuating element
Figure 6 — Fault reaction time control for ERT
3.111
non-volatile lock-out
safety shutdown condition of the system, where a restart can only be accomplished by a manual reset of
the system and by no other means
[SOURCE: EN 298:2012, 3.121.1]
3.112
volatile lock-out
safety shutdown condition of the system, where a restart can only be accomplished by either a manual
reset of the system or an interruption of the mains power and its subsequent restoration
[SOURCE: EN 298:2012, 3.121.2]
3.113
normal operation
operation of the ERC, ERS or ERT control system within its specification including the effect of
influences which may occur during intended operation
Note 1 to entry: Examples of influences on sensors are given in Table AA.1.
3.114
abnormal operation
operation under the effect of internal failures of the ERC, ERS or ERT control system
3.115
form closure construction
construction ensuring non-slippage
3.116
accuracy
ability to provide an indicated value close to the true value
prEN 12067-2:2015 (E)
4 Classification
4.1 Classes of control
EN 13611:2015, 4.1 is not applicable.
4.2 Groups of control
EN 13611:2015, 4.2 is not applicable.
4.3 Classes of control functions
Shall be according to EN 13611:2015, 4.3 with the following addition:
— ERC is a class C control function;
— ERS is a class C control function;
— ERT is a class C control function.
If the above specified classes of controls function are combined with each other or with other fuel/air
ratio control technologies, e.g. pneumatic, mechanic, the ERC, ERS or ERT can have a lower class of
control function if the total ratio control system complies with class C control function.
4.4 Types of DC supplied controls
Shall be according to EN 13611:2015, 4.4.
5 Test conditions and uncertainty of measurements
Shall be according to EN 13611:2015, Clause 5.
6 Design and construction
6.1 General
Shall be according to EN 13611:2015, 6.1 with the following addition:
6.1.101 General structure and feedback types
The ERC shall consist of at least two actuators and at least one sensor, see Figure 1 and Table 1 which
shall be considered together.
The ERS shall consist of at least one sensor and one output to initiate a safety shutdown or one output
to initiate reaching a safe state, see Figure 2 and Table 1 which shall be considered together.
The ERT shall consist of at least one output to trim the fuel / air ratio and at least one sensor, see Figure
3 and Table 1 which shall be considered together.
The ERC, ERS or ERT shall have continuous self-checking functions when their control function is in
force. In periods of time where the ERC, ERS or ERT is not in force, e.g. in stand-by or inactive, any fault
in its control function shall not unsafely influence the fuel / air ratio.
The complete system shall include the peripheral elements, e.g. servo motors, actuators, positional
devices, sensors, variable speed controls for combustion air fans and combustion analysis feedback
systems.
prEN 12067-2:2015 (E)
Table 1 — Acceptable feedback types
Actuator feedback Actuator output Process feedback
feedback
b d
Position Speed Flow/ΔP P Fuel/air Flame Flue gas
ratio
Actuator Valve / X  X X X X X
damper
a, e
Air fan  X X X
Actuator valve / X  X X
pump /
damper
Fuel pressure   X X
regulator
c c
At least 2 feedbacks (1 fuel, 1 air) required At least 1 feedback required
a
If a fan speed signal is used as means to control the air flow, proof of air flow cannot rely on fan rotation alone. A possible additional
signal can be derived from an independent air proving device at least checked during start up.
b
A feedback signal which is directly related to the mechanical part of the actuator.
c
The two actuator feedbacks and the process feedback are alternatives.
d
see 7.101.1
e
A feedback out of a variable speed drive cannot be used as long as this feedback signal is not derived through a class C control function
representing the actual fan speed.
If ERC, ERS or ERT controls are combined with each other or with other fuel/air ratio control
technologies, e.g. pneumatic, mechanical, any ERC, ERS or ERT can have a lower class of control function
provided the total ratio control system complies with class C requirements.
6.2 Mechanical parts of the control
Shall be according to EN 13611:2015, 6.2 with the following addition:
6.2.101 Use of non-metallic material
The following aspects shall be considered for fuel/air ratio components constructed of non-metallic
material:
— dimensional stability;
— flow characteristics of the material;
— possible heat shrinkage;
— durability.
They shall be considered with respect to the mechanical, chemical, thermal and environmental
conditions of the intended use.
6.2.102 Special requirements for electromechanical actuators with position feed-back sensors
The mechanical connection between the actuator and the actuator feed-back sensor, which represents
e.g. the position or flow, shall be of form closure construction or of adequate design. This requirement
shall include the complete connection up to the shaft of the control element (e.g. butterfly valve, air
damper).
Screws, pins and other components which are necessary to ensure form closure shall be secured, e.g. by
glue.
prEN 12067-2:2015 (E)
6.3 Materials
Shall be according to EN 13611:2015, 6.3.
6.4 Gas connections
EN 13611:2015, 6.4 is not applicable.
6.5 Electronic parts of the control
6.5.1 General
Shall be according to EN 13611:2015, 6.5.1 with the following modification:
Replace the third paragraph.
The ERC, ERS or ERT shall be designed such that changes in critical component values (such as those
affecting timing, sequence, accuracy) within the worst case specifications of the components, including
the long-term stability, shall result in the control continuing to function in accordance with this
standard. Compliance shall be checked by worst case analysis.
6.5.2 Switching elements
EN 13611:2015, 6.5.2 is not applicable.
6.5.3 Electrical components
6.5.3.1 Performance of electrical components
Shall be according to EN 13611:2015, 6.5.3.1.
6.5.3.2 Test
Shall be according to EN 13611:2015, 6.5.3.2.
6.5.3.3 Sensing element
Shall be according to EN 13611:2015, 6.5.3.3.
6.5.3.4 Gas controls employing electrical components in the gas way
Shall be according to EN 13611:2015, 6.5.3.4.
6.6 Protection against internal faults for the purpose of functional safety
6.6.1 Design and construction requirements
Shall be according to EN 13611:2015, 6.6.1 with the following addition
Where ever in a reference to EN 13611 the terms lock-out or safety shutdown are used they shall be
replaced by the term safe state.
6.6.2 Class A
Shall be according to EN 13611:2015, 6.6.2
NOTE This class of control functions is only applicable if the control function is combined with other ERC,
ERS or ERT see 6.1.101.
6.6.3 Class B
Shall be according to EN 13611:2015, 6.6.3.
prEN 12067-2:2015 (E)
NOTE This class of control functions is only applicable if the control function is combined with other ERC,
ERS or ERT see 6.1.101.
6.6.4 Class C
6.6.4.1 Design and construction requirements
Shall be according to EN 13611:2015, 6.6.4.1 with the following modification:
Replace the last paragraph by the following paragraphs:
The ERC, ERS or ERT shall be fail-safe. Systems which meet the requirements of this clause and, if
applicable, 6.6.1, are considered to be inherently fail-safe.
For the purpose of the fault assessment the behaviour and fault modes according Annex AA shall be
considered too.
The circuitry and the construction of the system shall be such that they meet the requirements of 7.101.
They shall be appraised according to the requirements to 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.
Any interface and interlock between the ERC, ERS or ERT and automatic burner control system shall not
degrade the safety of the complete system.
An ERC, ERS or ERT shall use a feedback system which ensures the fuel to air ratio meets the
requirements of 7.101.7 over the load range.
Information shall be provided for the safety related segments of the software. Information of the non-
safety related sections shall be sufficient to establish that it does not influence the safety related
sections.
If ERC, ERS or ERT controls are combined with each other or with other fuel/air ratio control
technologies, e.g. pneumatic, mechanical, any ERC, ERS or ERT can have a lower class of control function
provided the total ratio control system complies with class C requirements.
6.6.4.2 First fault
Shall be according to EN 13611:2015, 6.6.4.2 with the following modification:
— list item c) is only applicable for ERS if the ERS is a Class C control function and is combined with
1) a pneumatic gas/air ratio control according EN 88-1, or
2) a mechanical fuel/air ratio control, or
3) an ERC or ERT according to this standard complying at least as a Class B control function.
— the fault reaction time shall be as specified in the technical documentation, considering 7.101.5 and
the fault tolerating time if given in the relevant application standard.
6.6.4.3 Second fault
Shall be according to EN 13611:2015, 6.6.4.3 with the following modification:
— List item b) is applicable unless the ERC, ERS or ERT can make use of a cyclic operation of the
appliance not exceeding 24h in operation, in which case list item a) is applicable.
prEN 12067-2:2015 (E)
6.6.4.4 Faults during lock-out or safety shutdown
6.6.4.4.1 General
Shall be according to EN 13611:2015, 6.6.4.4.1 with the following addition:
6.6.4.4.2 First fault introduced during lock-out or safety shutdown
Shall be according to EN 13611:2015, 6.6.4.4.2 with the following modification:
— the fault reaction time control (FRTc) shall be as specified in the technical documentation,
considering 7.101.5 and the fault tolerating time if given in the relevant application standard.
6.6.4.4.3 Second fault introduced during lock-out or safety shutdown
Shall be according to EN 13611:2015, 6.6.4.4.3.
6.6.5 Circuit and construction evaluation
Shall be according to EN 13611:2015, 6.6.5.
7 Performance
7.1 General
Shall be according to EN 13611:2015, 7.1.
7.2 Leak-tightness
Shall be according to EN 13611:2015, 7.2.
7.3 Torsion and bending
Shall be according to EN 13611:2015, 7.3.
7.4 Rated flow rate
Shall be according to EN 13611:2015, 7.4.
7.5 Durability
Shall be according to EN 13611:2015, 7.5.
7.6 Performance tests for electronic controls
7.6.1 At ambient temperature
Shall be according to EN 13611:2015, 7.6.1 with the following addition:
The ERC, ERS or ERT shall comply with the requirements of 7.101.
7.6.2 At minimum temperature
Shall be according to EN 13611:2015, 7.6.2 with the following addition:
The ERC, ERS or ERT shall comply with the requirements of 7.101.
7.6.3 At maximum temperature
Shall be according to EN 13611:2015, 7.6.3 with the following addition:
The ERC, ERS or ERT shall comply with the requirements of 7.101.
prEN 12067-2:2015 (E)
7.7 Long-term performance for electronic controls
7.7.1 General
EN 13611:2015, 7.7.1 shall be replaced by the following:
7.7.1.101 Test requirements
All elements of the ERC, ERS or ERT which include electronic components shall withstand the tests as
deta
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