oSIST prEN 746-11:2020
(Main)Industrial thermoprocessing equipment - Part 11: Safety requirements for protective systems
Industrial thermoprocessing equipment - Part 11: Safety requirements for protective systems
This part of EN 746 specifies the requirements for protective systems used in industrial furnaces and associated processing equipment (TPE).
The functional requirements to which the protective systems apply are specified in the other parts of the EN 746 series.
Industrielle Thermoprozessanlagen - Teil 11: Sicherheitsanforderungen an Schutzsysteme
Dieser Teil von EN 746 legt die Anforderungen an Schutzsysteme, die in Industrieöfen und zugehörigen Prozessanlagen (TPE) verwendet werden, fest.
Die funktionalen Anforderungen, die für Schutzsysteme gelten, werden in den anderen Teilen der Normenreihe EN 746 festgelegt.
Équipements thermiques industriels - Partie 11 : Prescriptions de sécurité pour les systèmes de protection
La présente partie de l’EN 746 spécifie les exigences pour les systèmes de protection utilisés dans les fours industriels et les équipements thermiques associés (TPE).
Les exigences fonctionnelles auxquelles les systèmes de protection s’appliquent sont spécifiées dans les autres parties de la série EN 746.
Industrijska termoprocesna oprema - 11. del: Varnostne zahteve za zaščitne sisteme
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
01-marec-2020
Industrijska termoprocesna oprema - 11. del: Varnostne zahteve za zaščitne
sisteme
Industrial thermoprocessing equipment - Part 11: Safety requirements for protective
systems
Industrielle Thermoprozessanlagen - Teil 11: Sicherheitsanforderungen an
Schutzsysteme
Équipements thermiques industriels - Partie 11 : Prescriptions de sécurité pour les
systèmes de protection
Ta slovenski standard je istoveten z: prEN 746-11
ICS:
25.180.01 Industrijske peči na splošno Industrial furnaces in general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
DRAFT
EUROPEAN STANDARD
NORME EUROPÉENNE
EUROPÄISCHE NORM
January 2020
ICS 25.180.01
English Version
Industrial thermoprocessing equipment - Part 11: Safety
requirements for protective systems
Équipements thermiques industriels - Partie 11 : Industrielle Thermoprozessanlagen - Teil 11:
Prescription de sécurité pour les systèmes de Sicherheitsanforderungen an Schutzsysteme
protection
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 186.
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, 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, 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: Rue de la Science 23, B-1040 Brussels
© 2020 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 746-11:2020 E
worldwide for CEN national Members.
Contents Page
European foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 6
4 Design requirements for equipment in a protective system . 9
4.1 General . 9
4.2 Requirements for protective systems. 10
4.3 Fault assessment for the hardwired section of protective systems . 19
4.4 Failure of utilities . 19
4.5 Reset . 20
Annex A (informative) Explanation of techniques and measures for avoiding systematic
faults . 21
Annex B (informative) Examples of techniques for avoiding failures from external wiring . 23
Annex C (informative) Examples for the determination of safety integrity level SIL using the
risk graph method . 27
Annex D (informative) Example of an extended risk assessment for one safety
instrumented function using the EN 61511 method . 46
Annex E (informative) Sample schematic diagrams of protective system . 54
Annex F (normative) Hardwiring protective systems . 64
Annex ZA (informative) Relationship between this European Standard and the essential
requirements of Directive 2006/42/EC aimed to be covered . 74
Bibliography . 76
European foreword
This document (prEN 746-11:2020) has been prepared by Technical Committee CEN/TC 186
“Industrial Thermoprocess Equipment - Safety”, the secretariat of which is held by DIN.
This document is currently submitted to the CEN Enquiry.
The contents of prEN 746-11:2020 are based on parts of EN 746-2:2009 and ISO 13577-4:2016.
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 Directive(s).
For relationship with EU Directive(s), see informative Annex ZA, which is an integral part of this
document.
Introduction
This part of EN 746 was developed to specify the requirements of a protective system, which is a safety-
related electrical control system (SRECS) of industrial thermoprocessing equipment and associated
processing equipment (TPE).
Mandatory safety-related control functions of TPE are specified in EN 746-1, EN 746-2, and EN 746-3.
It is intended that in designing the protective system of TPE, manufacturers of TPE choose from the four
methods provided in this part of EN 746.
This part of EN 746 is to be used together with the other parts of EN 746 with the principles of
EN ISO 12100. However, there are cases in which a risk assessment according to EN 61511 (all parts) is
more suitable for the design of a TPE protective system.
This document is a type-C standard as stated in EN ISO 12100.
The machinery concerned and the extent to which hazards, hazardous situations, or hazardous events
are covered are indicated in the scope of this part of EN 746.
When requirements of this type-C standard are different from those which are stated in type-A or -B
standards, the requirements of this type-C standard take precedence over the requirements of the other
standards for machines that have been designed and built according to the requirements of this type-C
standard.
EN 61511 (all parts) provides the option of a low-demand rate on the protective system.
EN 62061:2005 or EN ISO 13849-1:2015 always assume high-demand applications.
Therefore, this part of EN 746 permits extended risk assessment for SRECS in which risk assessment
based on EN 61511 (all parts) can be chosen as an alternative.
1 Scope
This part of EN 746 specifies the requirements for protective systems used in industrial furnaces and
associated processing equipment (TPE).
The functional requirements to which the protective systems apply are specified in the other parts of
the EN 746 series.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable to its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
1)
prEN ISO 13574:— , Industrial furnaces and associated processing equipment — Vocabulary
EN 298:2012, Automatic burner control systems for burners and appliances burning gaseous or liquid
fuels
EN ISO 13849-1:2015, Safety of machinery - Safety-related parts of control systems - Part 1: General
principles for design (ISO 13849-1:2015)
EN 14597:2012, Temperature control devices and temperature limiters for heat generating systems
EN IEC 60947-4-1:2019, Low-voltage switchgear and controlgear — Part 4-1: Contactors and motor-
starters - Electromechanical contactors and motor-starters (IEC 60947-4-1:2018)
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)
EN 60204-1:2018, Safety of machinery — Electrical equipment of machines — Part 1: General
requirements (IEC 60204-1:2016)
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 61508 (all parts), Functional safety of electrical/electronic/programmable electronic safety-related
systems (IEC 61508)
EN 61131-3:2013, Programmable controllers — Part 3: Programming languages (IEC 61131-3:2013)
EN 61511 (all parts), Functional safety — Safety instrumented systems for the process industry sector (IEC
61511 (all parts))
2)
EN 62061:2005 , Safety of machinery — Functional safety of safety-related electrical, electronic and
programmable electronic control systems (IEC 62061:2005)
1) Under preparation.
2) This document is impacted by the amendments EN 62061:2005/A1:2013 and EN 62061:2005/A2:2015.
3 Terms and definitions
For the purposes of this document, the terms and definitions given in prEN ISO 13574 and the following
apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at https://www.iso.org/obp
3.1
final element
part of a protective system which implements the physical action necessary to achieve a safe state
Note 1 to entry: Examples are valves, switch gear, motors including their auxiliary elements, for example, a
solenoid valve and actuator if involved in the safety function.
[SOURCE EN 61511-1:2017, 3.2.24 modified: "instrumented system" had been changed to read
"protective system" in the definition.]
3.2
flame detector device
device by which the presence of a flame is detected and signaled
Note 1 to entry: It can consist of a flame sensor, an amplifier, and a relay for signal transmission.
[SOURCE: prEN ISO 13574:—, 2.65, modified: The second sentence in the original definition had been
presented as in the Note.]
3.3 automatic burner control system
protective system comprised of at least a programming unit and all the elements of a flame detector
device
Note 1 to entry: The various functions of an automatic burner control system can be in one or more housings.
[SOURCE: prEN ISO 13574:—, 2.5, modified: The second sentence in the original definition had been
presented as in the Note.]
3.4
functional safety
capability of a protective system or other means to reduce risk, to execute the actions required for
achieving or maintaining a safe state for the process and its related equipment
[SOURCE: prEN ISO 13574:—, 2.73]
3.5
logic function
function that performs the transformations between input information (provided by one or more input
functions or sensors) and output information (used by one or more output functions or final elements)
Note 1 to entry: Logic functions are executed by the logic solver of a protective system.
[SOURCE: EN 61511-1:2017, 3.2.39, modified — "input functions" had been changed to read "input
functions or sensors" and "output function" had been changed to read "output function or final
elements" in the definition, and the second sentence in the original definition had been deleted; Note
has been added.]
3.6
logic solver
portion of a protective system that performs one or more logic function(s)
Note 1 to entry: Examples are electrical systems, electronic systems, programmable electronic systems,
pneumatic systems, and hydraulic systems. Sensors and final elements are not part of the logic solver.
[SOURCE: EN 61511-1:2017, 3.2.40 modified: "either a BPCS or SIS" had been changed to read "a
protective system" in the definition; Note 1 in the original definition had been deleted.]
3.7
manual reset
action after a lockout of a safety device (e.g. automatic burner control) carried out manually by the
supervising operator
[SOURCE: prEN ISO 13574:—, 2.107]
3.8
performance level
PL
discrete level used to specify the ability of safety-related parts of control systems to perform a safety
function under foreseeable conditions
[SOURCE: EN ISO 13849-1:2015, 3.1.23]
3.9
product standard
standard for products and devices which are listed in EN 746 (all parts) except this part of EN 746
[SOURCE: prEN ISO 13574:—, 2.135 modified:
...
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