SIST EN 50556:2019
(Main)Road traffic signal systems
Road traffic signal systems
This document specifies requirements for Road Traffic Signal Systems, including their development, design,
testing, installation and maintenance.
In particular, it forms the electrotechnical part of the following two standards issued by CEN:
— EN 12368, Traffic control equipment ― Signal heads;
— EN 12675, Traffic signal controllers ― Functional safety requirements.
Each of these standards above will be used with this standard either singly or together to define an
operational equipment or system. This will be achieved by using the electrotechnical methods and testing
defined in this standard.
Where Road Traffic Signal Systems are to be used with other systems, e.g. public lighting or railway
signalling and communication, this document will be used with any other respective standard(s) for the other
associated systems to ensure that overall safety is not compromised.
This document is applicable to traffic signal control equipment permanently and temporarily installed, and
portable traffic control equipment, with the exception of portable traffic signal equipment only capable of
controlling alternate / shuttle working lanes (as further defined in 3.2.10).
Straßenverkehrs-Signalanlagen
This European Standard specifies requirements for Road Traffic Signal Systems, including their development, design, testing, installation and maintenance.
In particular, it forms the electrotechnical part of the following two standards issued by CEN:
– EN 12368, Traffic control equipment ― Signal heads
– EN 12675, Traffic signal controllers ― Functional safety requirements
Each of these standards above should be used with this standard either singly or together to define an operational equipment or system. This should be achieved by using the electrotechnical methods and testing defined in this standard.
Where Road Traffic Signal Systems are to be used with other systems, e.g. public lighting or railway signalling and communication, this standard should comply with the other respective standard to ensure that overall safety is not compromised.
Only permanently or temporarily installed Road Traffic Signal Systems are included in this standard. Central office and portable signalling systems are not covered.
Systèmes de signaux de circulation routière
Sistemi prometne signalizacije
Vsak od zgornjih standardov se bo uporabljal s tem standardom posamezno ali skupaj pri opredeljevanju
operativne opreme ali sistema. To se bo zagotovilo z uporabo elektrotehničnih metod in preskušanja, opredeljenih v tem standardu.
Kjer se bodo sistemi prometne signalizacije uporabljali z drugimi sistemi, npr. javno razsvetljavo ali železniško
signalizacijo in komunikacijo, se bo ta dokument uporabljal skupaj z drugimi zadevnimi standardi za druge povezane sisteme, da se zagotovi celotna varnost.
Ta dokument se uporablja za trajno in začasno nameščeno opremo za nadzor prometa ter prenosno opremo za nadzor prometa, razen za prenosno opremo za prometno signalizacijo, ki lahko nadzoruje samo izmenične/zožane delovne pasove (kot je dodatno opredeljeno v 3.2.10).
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN 50556:2019
01-julij-2019
Nadomešča:
SIST EN 50556:2011
Sistemi prometne signalizacije
Road traffic signal systems
Straßenverkehrs-Signalanlagen
Systèmes de signaux de circulation routière
Ta slovenski standard je istoveten z: EN 50556:2018
ICS:
93.080.30 Cestna oprema in pomožne Road equipment and
naprave installations
SIST EN 50556:2019 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST EN 50556:2019
EUROPEAN STANDARD
EN 50556
NORME EUROPÉENNE
EUROPÄISCHE NORM
September 2018
ICS 93.080.30 Supersedes EN 50556:2011
English Version
Road traffic signal systems
Systèmes de signaux de circulation routière Straßenverkehrs-Signalanlagen
This European Standard was approved by CENELEC on 2017-12-18. CENELEC 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 CENELEC 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 CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the
same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden,
Switzerland, Turkey and the United Kingdom.
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2018 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN 50556:2018 E
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Contents Page
European foreword . 6
Introduction . 7
1 Scope . 8
2 Normative references . 8
3 Terms and definitions . 9
4 Electrical supply and limits . 17
4.1 Nominal voltages . 17
4.2 Operating voltage range . 17
4.3 Low voltage . 18
4.3.1 Auxiliary state switch response voltage (V ) . 18
aux
4.3.2 Power up activation voltage . 18
4.4 Overvoltage . 18
4.5 Voltage dip . 18
4.6 Mains frequency . 19
5 Safety . 19
5.1 Electrical safety . 19
5.1.1 General . 19
5.1.2 Controller Signal outputs . 20
5.1.3 Interconnections . 21
5.1.4 Cables . 21
5.1.5 Insulation . 22
5.2 Traffic safety . 23
5.2.1 General . 23
5.2.2 Requirements of signal intensity for safety . 23
5.2.3 Requirements for signal states . 23
5.2.4 Failure consideration (Failure mode analysis) . 25
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5.2.5 Location of monitoring elements for signals . 28
6 Testing . 28
6.1 Object . 28
6.2 Organization of testing . 28
6.2.1 Ordering of tests . 28
6.2.2 Presentation of equipment . 29
6.3 Environmental tests. 30
6.3.1 General conditions for the tests . 30
6.3.2 Random vibration test (in accordance with EN 60068-2-64) . 31
6.3.3 Impact tests . 31
6.3.4 Degree of protection (in accordance with EN 60529) . 31
6.3.5 Dry heat (in accordance with EN 60068-2-2) . 32
6.3.6 Cold (in accordance with EN 60068-2-1) . 32
6.3.7 Damp heat (in accordance with EN 60068-2-30) . 32
6.3.8 Solar radiation (in accordance with EN 60068-2-5) . 32
6.4 Electrical tests . 33
6.4.1 Scope of electrical compatibility tests . 33
6.4.2 Output to signal heads . 33
6.4.3 External input tests . 33
6.4.4 External output tests . 33
6.4.5 Communications interface circuits . 34
6.5 Electrical safety tests . 34
6.5.1 General . 34
6.5.2 Typical test conditions . 34
6.5.3 Protective conductors continuity test . 34
6.5.4 Labelling . 34
6.5.5 Access to hazardous voltages . 35
6.5.6 Protection against fire risks . 35
6.5.7 Test of residual current protection means for the installation . 35
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6.5.8 Test of residual current protection means for maintenance supplies . 35
6.5.9 Electrical strength test . 35
6.6 Traffic safety tests . 35
6.6.1 Safety tests (EN 12675) . 35
6.6.2 Undervoltage tests . 36
6.6.3 Power up activation voltage test . 36
6.6.4 Overvoltage test . 36
6.6.5 Power supply voltage dips . 36
6.7 Electromagnetic compatibility testing . 36
7 Electrical interfaces . 37
7.1 General . 37
7.2 Detector interface . 37
8 Installation . 37
8.1 General . 37
8.2 Tests carried out during installation . 38
8.3 Test of cables following the installation of cables . 38
8.4 Inspection of terminations following the installation and termination of all equipment and
cables . 38
8.5 Test of impedance . 39
8.5.1 Protective conductors continuity . 39
8.5.2 Earth impedance test . 39
8.5.3 Fault loop impedance test . 39
8.6 Insulation of live parts to earth . 39
8.7 RCD (residual current device / earth leakage breaker) . 40
8.8 Fuses . 40
8.9 Voltage and polarity of supply . 40
8.10 Connections between controllers, signals and ancillary equipment . 40
8.11 Safety covers . 40
8.12 Functional check of road traffic signal systems . 40
9 Maintenance . 41
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9.1 General . 41
9.2 Types of maintenance . 41
9.3 Documentation required for maintenance . 41
9.4 Equipment not covered by this standard . 42
9.5 Safety testing procedures . 42
9.6 Maintenance testing procedures . 43
10 Marking and labelling . 44
11 Classification of environmental test conditions . 45
Bibliography . 49
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EN 50556:2018 (E)
European foreword
This document (EN 50556:2018) has been prepared by CENELEC Task Force CLC/BTTF 69-3 "Road traffic
signal systems".
The following dates are fixed:
• latest date by which this document has (dop) 2019-03-28
to be implemented at national level by
publication of an identical national
standard or by endorsement
• latest date by which the national (dow) 2021-09-28
standards conflicting with this document
have to be withdrawn
This document supersedes EN 50556:2011.
EN 50556:2018 includes the following significant technical changes with respect to EN 50556:2011:
— change in the Scope to cover non-permanent signals of a certain level of complexity;
— correct the normative usage of shall and should within the whole document;
— update of the normative references to add EN 50159;
— updated invalid reference in 3.3.5 to IEC 60050-826;
— updated invalid reference from HD 384.4 to the HD 60364-4 series;
— updated invalid reference from IEC 60536 to EN 61140;
— clarified wording of requirements in 5.2.3.2;
— change of the definition of “Road traffic signal system” to fulfil formal requirements;
— additions to terms and definitions in 3.2.7 to 3.2.10;
— modification of 5.1.2 to accommodate new forms of architecture that are seen as possible in the future,
an adaptation to the level of technology;
— modification of 5.2.3.3 (last sentence) to reference the changes made to 5.1.2;
— modification of 5.2.3.4, Class X1 last paragraph, to reference the changes made to 5.1.2;
— modification of 5.2.3.4, Class X2 note added to reference the changes made to 5.1.2;
— added a note at 6.3.1.3 b) for clarification about the test setup.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CENELEC shall not be held responsible for identifying any or all such patent rights.
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Introduction
To satisfy the legal and regulatory requirements and specific provisions of each CENELEC country, certain
characteristics in this standard contain a range, which is defined by a number of discrete classes. The class
to be used in the country will be selected by the Standards Authority of the CENELEC member of that country
from the range specified.
Thus, this European Standard contains the essential electrotechnical requirements of all CENELEC countries
and permits through the class selection procedure, countries to incorporate their own requirements.
It is believed that this first step will allow, over a period of time, a gradual alignment of Road Traffic Signal
Systems in Europe.
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1 Scope
This document specifies requirements for Road Traffic Signal Systems, including their development, design,
testing, installation and maintenance.
In particular, it forms the electrotechnical part of the following two standards issued by CEN:
— EN 12368, Traffic control equipment ― Signal heads;
— EN 12675, Traffic signal controllers ― Functional safety requirements.
Each of these standards above will be used with this standard either singly or together to define an
operational equipment or system. This will be achieved by using the electrotechnical methods and testing
defined in this standard.
Where Road Traffic Signal Systems are to be used with other systems, e.g. public lighting or railway
signalling and communication, this document will be used with any other respective standard(s) for the other
associated systems to ensure that overall safety is not compromised.
This document is applicable to traffic signal control equipment permanently and temporarily installed, and
portable traffic control equipment, with the exception of portable traffic signal equipment only capable of
controlling alternate / shuttle working lanes (as further defined in 3.2.10).
2 Normative references
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 12368, Traffic control equipment - Signal heads
EN 12675:2017, Traffic signal controllers - Functional safety requirements
EN 50102, Degrees of protection provided by enclosures for electrical equipment against external mechanical
impacts (IK code)
EN 50110-1, Operation of electrical installations – Part 1: General requirements
EN 50129, Railway applications - Communication, signalling and processing systems - Safety related
electronic systems for signalling
EN 50159:2010, Railway applications - Communication, signalling and processing systems - Safety-related
communication in transmission systems
EN 50293, Road traffic signal systems - Electromagnetic compatibility
EN 60068-2-1:2007, Environmental testing – Part 2-1: Tests – Test A: Cold (IEC 60068-2-1:2007)
EN 60068-2-2:2007, Environmental testing – Part 2-2: Tests – Test B: Dry heat (IEC 60068-2-2:2007)
EN 60068-2-5:2011, Environmental testing – Part 2: Tests – Test Sa: Simulated solar radiation at ground
level (IEC 60068-2-5:2010)
EN 60068-2-14:2009, Environmental testing – Part 2-14: Tests – Test N: Change of temperature
(IEC 60068-2-14:2009)
EN 60068-2-30:2005, Environmental testing – Part 2-30: Tests – Test Db: Damp heat, cyclic (12 h + 12 h
cycle) (IEC 60068-2-30:2005)
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EN 60068-2-64:2008, Environmental testing – Part 2-64: Tests – Test Fh: Vibration, broadband random and
guidance (IEC 60068-2-64:2008)
HD 60364-4-41:2007, Low-voltage electrical installations – Part 4-41: Protection for safety - Protection
against electric shock (IEC 60364-4-41:2005)
HD 60364-4 (all parts), Low-voltage electrical installations – Part 4: Protection for safety (IEC 60364-4 series)
HD 60364-5-54, Low-voltage electrical installations – Part 5-54: Selection and erection of electrical
equipment - Earthing arrangements and protective conductors (IEC 60364-5-54)
EN 60529:1991, Degrees of protection provided by enclosures (IP Code) (IEC 60529:1989)
EN 60950-1:2006, Information technology equipment – Safety – Part 1: General requirements
(IEC 60950-1:2005, modified)
EN 61008 (all parts), Residual current operated circuit-breakers without integral overcurrent protection for
household and similar uses (RCCB's) (IEC 61008 series)
EN 61140:2016, Protection against electric shock - Common aspects for installation and equipment
(IEC 61140:2016)
IEC 60050-191, International Electrotechnical Vocabulary – Chapter 191: Dependability and quality of service
IEC 60050-192, International electrotechnical vocabulary – Part 192: Dependability
IEC 60183, Guidance for the selection of high-voltage A.C. cable systems
IEC 60417, Graphical symbols for use on equipment [database]
3 Terms and definitions
For the purposes of this document, the following terms and definitions 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 http://www.iso.org/obp
3.1 General:
3.1.1
road traffic signal systems
systems for the safe control of the traffic flow at junctions, pedestrian crossings and other places with
conflicting traffic using light signals
Note 1 to entry: They may consist of the following elements, which is not in itself a complete list:
– controllers;
– signal heads, signalling devices and traffic signs:
e.g. signal heads for traffic signals;
acoustic signal generators;
mechanical signal generators;
traffic signs connected to the Road Traffic Signal System;
– traffic sensors and detectors:
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e.g. request push buttons;
vehicle detectors / Pedestrian Detectors;
– monitoring equipment:
e.g. photographic monitoring devices;
– equipment Enclosures;
– electrical Supply;
– cables;
– interconnections;
– supports.
3.1.2
failure mode analysis
means of examining all failure modes to ensure that signal states endangering the road users and/or risk of
electrical hazard cannot occur during normal conditions of operation of a Road Traffic Signal System or if
they do occur as a result of, or whilst a failure (failure mode) exists, that the signal states endangering the
road users are detected and prevented from continuing
3.1.3
signal safeguarding facility
facilities intended to prevent states of signals endangering the traffic
3.1.4
monitoring element
device that signals electrical and mechanical states of equipment, preferably for signal circuits, and which
converts the obtained information in such a manner that it can be processed in signal safeguarding facilities
3.1.5
hardware
complete Road Traffic Signal System or a (material) part of it
3.1.6
hardware fault
failures of components and any influence that will cause the equipment to fail
Note 1 to entry: Systematic hardware faults constitute either design faults or systematic production faults.
3.1.7
software
all or part of the sequence instructions for a Road Traffic Signal System including the affiliated documentation
Note 1 to entry: Software is exclusively immaterial, so that it is subject to no wear or failure mechanisms. Once
implemented, software cannot be falsified on its own.
3.1.8
software error
deviation between the realised and intended functional contents of the software
Note 1 to entry: All errors in the software are systematic errors. They are caused by:
— invalid specification (incorrect formulation of intention);
— incorrect programming (incorrect translation of the specification to sequential instructions).
Apparent program falsification in memories is produced by hardware faults or failures or is caused by inadmissible
influencing.
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3.2 Traffic engineering:
3.2.1
controllers (traffic)
electrical device to control signals
3.2.2
signal group
sequence of conditions applied to a group of signal heads, which always received identical signal light
indications
3.2.3
operating system
principle software that allows a computer to operate, and which establishes the basic foundations, protocols
and functions that the computer can perform, including communication with internal and external resources
3.2.4
application program
software that determines specific tasks that a computer can perform, i.e. operate as a traffic controller
Note 1 to entry: Application software rests on and extends the capabilities of the operating system to meet customer
needs.
3.2.5
traffic data
data, which specifies how the application program will perform in the particular circumstances of one traffic
system
Note 1 to entry: This may be considered to be in two parts.
3.2.5.1
traffic safety data
all Traffic Data stored in non-volatile memory that has a direct impact on the safety of road users
3.2.5.2
traffic non safety data
all the remainder of the data, which will not cause an unacceptable danger to the road user if the data is
changed
3.2.6
design authority
design responsible
individual or group (organisation) responsible for the safe design and manufacturing, including the
instructions for safe use, installation and maintenance of the equipment or system
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3.2.7
centralised power supply and centralised intelligence
example traffic control system, close coupled within a cabinet where both the power supply and intelligence
(the safety elements that switch the lamps and monitor the states of those switches) are centralised
Key
1 cabinet in which all elements are close coupled
2 central processing / controller application
3 safety signal switching and monitoring elements
4 close coupled communication within controlled environment
5 power
6 power switch to remove power from external elements (part of signal safeguarding facility)
7 switched power to illuminate signals
8 traffic / Pedestrian signals (filament / LED)
9 power to signal switching elements that can be switched off / removed.
Figure 1 — Example of conventional close coupled safety system
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3.2.8
centralised power supply, distributed Intelligence system
system in which the distributed intelligence safety data is transferred between a central control process and
distributed switching elements and in which, however, power is still distributed from a central source and can
be switched off at this point in case of emergency
Key
1 cabinet in which all e
...
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