Road traffic signal systems

Former EN 50278

Straßenverkehrs-Signalanlagen

Systèmes de signaux de circulation routière

Road traffic signal systems

General Information

Status
Withdrawn
Publication Date
31-Aug-2002
Withdrawal Date
06-Jan-2014
Technical Committee
Current Stage
9900 - Withdrawal (Adopted Project)
Start Date
06-Jan-2014
Due Date
29-Jan-2014
Completion Date
07-Jan-2014

RELATIONS

Effective Date
13-May-2010
Effective Date
07-Jan-2014

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SLOVENSKI STANDARD
SIST HD 638 S1:2002
01-september-2002
Road traffic signal systems
Road traffic signal systems
Straßenverkehrs-Signalanlagen
Systèmes de signaux de circulation routière
Ta slovenski standard je istoveten z: HD 638 S1:2001
ICS:
93.080.30 Cestna oprema in pomožne Road equipment and
naprave installations
SIST HD 638 S1:2002 en

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST HD 638 S1:2002
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SIST HD 638 S1:2002
HARMONIZATION DOCUMENT HD 638 S1
DOCUMENT D'HARMONISATION
HARMONISIERUNGSDOKUMENT January 2001
ICS 93.080.30
English version
Road traffic signal systems
Systèmes de signaux de circulation Straßenverkehrs-Signalanlagen
routière

This Harmonization Document was approved by CENELEC on 2000-04-01. CENELEC members are

bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for

implementation of this Harmonization Document on a national level.

Up-to-date lists and bibliographical references concerning such national implementation may be obtained

on application to the Central Secretariat or to any CENELEC member.

This Harmonization Document exists in three official versions (English, French, German).

CENELEC members are the national electrotechnical committees of Austria, Belgium, Czech Republic,

Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway,

Portugal, Spain, Sweden, Switzerland and United Kingdom.
CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
Central Secretariat: rue de Stassart 35, B - 1050 Brussels

© 2001 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.

Ref. No. HD 638 S1:2001 E
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Foreword

This Harmonization Document was prepared by the CENELEC Task Force BTTF 69-3 (TC 214 WG1),

Road traffic signal systems.

The text of the draft was submitted to the formal vote and was approved by CENELEC as HD 638 S1 on

2000-04-01.
The following dates were fixed:
– latest date by which the existence of the HD
has to be announced at national level (doa) 2000-10-01
– latest date by which the HD has to be implemented
at national level by publication of a harmonized
national standard or by endorsement (dop) 2001-08-01
– latest date by which the national standards conflicting
with the HD have to be withdrawn (dow) 2003-04-01
__________
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Contents

Introduction........................................................................................................................................... 4

1 Scope........................................................................................................................................... 5

2 Normative references.................................................................................................................. 5

3 Definitions ................................................................................................................................... 6

4 Electrical supply and limits ........................................................................................................ 9

5 Safety......................................................................................................................................... 11

6 Testing....................................................................................................................................... 19

7 Electrical interfaces................................................................................................................... 26

8 Installation................................................................................................................................. 26

9 Maintenance .............................................................................................................................. 29

10 Marking and labelling ............................................................................................................... 32

11 Classification of environmental test conditions ..................................................................... 33

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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 document 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 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 shall be used with this standard either singly or together to define an

operational equipment or system. This shall 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 shall 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.
2 Normative references

This European Standard incorporates by dated or undated reference, provisions from other publications.

These normative references are cited at the appropriate places in the text and the publications are listed

hereafter. For dated references, subsequent amendments to or revisions of any of these publications

apply to this European Standard only when incorporated in it by amendment or revision. For undated

references the latest edition of the publication referred to applies.
EN 12368 Traffic control equipment - Signal Heads
EN 12675 Traffic signal controllers – Functional safety requirements

EN 50102 1995 Degrees of protection provided by enclosures for electrical equipment

against external mechanical impacts (IK Code)
EN 50110-1 Operation of electrical installations

ENV 50129 Railway applications - Safety related electronic systems for signalling

EN 50293 Electromagnetic compatibility - Road traffic signal systems - Product
standard
EN 60529 1991 Degrees of protection provided by enclosures (IP Code)
+ corr. May 1993 (IEC 60529:1989)
EN 60598-1 Luminaires
Part 1: General requirements and tests (IEC 60598-1, mod)
EN 61008 series Electrical accessories
Residual current-operated circuit-breakers without integral overcurrent
protection for household and similar uses (RCCBs)
(IEC 61008 series, mod)
EN ISO 9001 Quality systems - Model for quality assurance in design/development,
production, installation and servicing
HD 384.2 International Electrotechnical Vocabulary
Chapter 826: Electrical installations of buildings (IEC 60050-826)
HD 384.4 series Electrical installations of buildings
Part 4: Protection for safety (IEC 60364-4 series, mod)
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HD 384.5.54 1988 Electrical installations of buildings
Part 5: Selection and erection of electrical equipment
Chapter 54: Earthing arrangements and protective conductors
(IEC 364-5-54:1980, mod).
EN 60068-2-1 Environmental testing - Part 2: Tests;
Test A: Cold (IEC 60068-2-1)
EN 60068-2-2 Basic environmental testing procedures; Part 2: Tests;
Test B: Dry heat (IEC 60068-2-2 + IEC 60068-2-2A)
EN 60068-2-5 Environmental testing - Part 2: Tests;
Test Sa: Simulated solar radiation at ground level (IEC 60068-2-5)
EN 60068-2-14 Environmental testing - Part 2: Tests;
Test N: Change of temperature (IEC 60068-2-14)
EN 60068-2-30 Environmental testing - Part 2: Tests;
Tests Db and guidance: Damp heat, cyclic (12 + 12-hour cycle)
(IEC 60068-2-30)

EN 60068-2-64 Environmental testing - Part 2: Test methods - Test Fh: Vibration, broad

band random (digital control) and guidance (IEC 60068-2-64)
EN 60417 series Graphical symbols for use on equipment (IEC 60417 series)
IEC 60050-191 International Electrotechnical Vocabulary
Chapter 191: Dependability and quality of service

IEC 60536 1992 Classification of electrical and electronic equipment with regard to protection

against electric shock
3 Definitions
3.1 General
3.1.1
Road Traffic Signal Systems

include systems and devices, provided they are affiliated to them in terms of circuitry.

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,
e.g. request push buttons,
vehicle detectors / Pedestrian Detectors
Monitoring equipment,
e.g. photographic monitoring devices
Equipment Enclosures
Electrical Supply
Cables
Interconnections
Supports
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3.1.2
Failure Mode Analysis

a 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 under failure mode that they can not continue
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 convert the obtained information in such a manner that it can be processed in signal safeguarding

facilities
3.1.5
hardware
the 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 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 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 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.
3.2 Traffic engineering
3.2.1
controllers (traffic)
an electrical device to control signals
3.2.2
signal group

the sequence of conditions applied to a group of signal heads, which always received identical signal

light indications
3.2.3
Operating System

the principle software that allows a computer to operate. This software establishes the basic foundations,

protocols and functions that the computer can perform, including communication with internal and

external resources
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3.2.4
Application Program

software that determines specific tasks that a computer can perform i.e. operate as a traffic controller.

Application software rests on and extends the capabilities of the operating system to meet customer

needs
3.2.5
Traffic Data

that data which specifies how the application program will perform in the particular circumstances of one

traffic system. This may be considered to be in 2 parts
3.2.5.1
Traffic Safety Data

is 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)

the 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

3.3 Electrotechnical
3.3.1
live part
See HD 384.2
3.3.2
enclosure (EN 50102)

a part providing protection of equipment against certain external influences and, in any direction

protection against contact

NOTE This definition from the existing International Electrotechnical Vocabulary (HD 384.2) needs the following explanations under

the scope of this standard.

1) Enclosures provide protection of equipment against harmful effects of mechanical impacts and protection of persons and livestock

against access to hazardous parts.

2) Barriers, shapes of openings or any other means - whether attached to the enclosure or formed by the enclosed equipment -

suitable to prevent or limit the penetration of the specified test probes are considered as part of the enclosure, except when they

can be removed without the use of a tool.
3.3.3
complete protection
protection that achieves the following:

a) effective and durable prevention of contact with live parts by the attachment of obstacles at least

conforming to type of protection IP2x as defined in EN 60529;

b) complete enclosure of live parts by insulating material that can be removed only by destruction

(protection by insulating envelopment)
3.3.4
partial protection

protection that prevents the possibility of accidental contact by persons or by objects usually handled by

them in one of the following ways:

a) by placing live parts at a distance that the possibility of accidental contact by persons or objects

usually handled by them is excluded (protection against accidental contact by a safety clearance);

b) by attaching obstacles conforming at least to type of protection IP1x as defined in EN 60529

(protection against accidental contact by the attachment of obstacles)
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3.3.5
reinforced insulation
See EN 60529
3.3.6
nominal voltages
See HD 384.2
3.3.7
earthed systems
See HD 384.2
3.3.8
Class 0 equipment
See IEC 60536
3.3.9
Class I equipment
See IEC 60536
3.3.10
Class II equipment
See IEC 60536
3.3.11
Class III equipment
See IEC 60536
3.3.12
safety extra-low voltage (SELV)
See IEC 60536
3.3.13
protective conductor (symbol PE)
See HD 384.2
3.3.14
earthing conductor
See HD 384.2
3.3.15
RCD
See EN 61008 and EN 61009
3.3.16
voltage dip
See IEC 60050-161
4 Electrical supply and limits
4.1 Nominal voltages

The standard nominal voltage for connection to the public supply shall be taken to be 230 V AC .

r.m.s
Other nominal voltages shall be permitted.
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4.2 Operating voltage range

The system shall be classified according to its mains voltage range within which the Road Traffic Signal

System shall work as defined by EN 12675, as follows:
Class A1: nominal voltage -13%...+10%;
Class A2: 220 volts -20%...+15%.

The system shall not display signals which contravene EN 12675 when the supply voltage is outside the

above voltage ranges.
4.3 Low voltage
4.3.1 Switch off response voltage (V )
off

The system shall be classified as follows according to whether or not it automatically switches off when

the supply voltage falls below a specified value.
Class B0: no automatic switch off is required;
Class B1: automatic switch off is required at nominal voltage -20%;
Class B2: automatic switch off is required at nominal voltage -25%.
4.3.2 Auxiliary state switch response voltage (V )
aux

The auxiliary state is a state specified by the customer which will occur when normal operation is not

satisfactory due to low supply voltage or other specified conditions. This state shall be specified by

EN 12675 as:
Signals off
Flashing Yellow
etc.

The system shall be classified as follows according to whether or not the system automatically switches

to an auxiliary state when the supply voltage falls below a specified value (V ).

aux.
Class C0: no auxiliary state is required;

Class C1: the system switches to the auxiliary state when the supply voltage has any value between

the minimum operating voltage as specified in 4.2 and V .
off
4.3.3 Power up activation voltage

The system shall become active when the supply voltage reaches a value within its operating voltage

range. The restart procedure shall normally be automatic or in exceptional circumstances it may be by

manual or remote control. No signalling state dangerous to traffic shall be possible and the signalling

state shall conform to EN 12675.
4.4 Overvoltage

The system shall be classified as follows according to whether or not a protective device is incorporated

which cuts off the supply voltage to prevent damage. Where incorporated, the protective device shall

operate when the supply voltage is greater than the operating voltage range.
Class D0: no protective device is required;
Class D1: a protective device is required to provide protection up to 1500 V .
r.m.s
4.5 Voltage dip

The system shall be classified according to the duration of dips in supply which affect the operation. In

order to avoid undesirable reactions by the signal safeguarding facilities, the system shall operate as

shown in Table 1 according to the duration of the voltage dip below V or V . Where B0 and C0 are

off aux.
specified, V or V shall be taken as zero.
off aux

Period t is a timeperiod of a voltage dip in the supply which will not affect the normal operation of the

system.
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Period t is a timeperiod of voltage dip in the supply when the system shall change to signals OFF

followed by the start up sequence.
Table 1 - Classification according to voltage dip (Values in milliseconds)
Criterion Class E1 Class E2 Class E3
Period t < 50 < 20 < 20
Period t >300 >800 >100
For Class E1, E2 or E3:

For any voltage dip in the supply between t and t the controller may remain working correctly or change

1 2
to signals OFF followed by the start up sequence.
4.6 Mains frequency

The system shall be classified as follows according to the acceptable variations in mains frequency.

Class F1: 50 Hz ±2%
Class F2: 50 Hz ±4%
Class F3: 50 Hz ±10%
Class F4: 60 Hz ±2%
4.7 Detectors

The detectors may be powered from a separate supply or from the controller. The recommended

voltages are:
The OPERATING VOLTAGE (see 4.2);
110 V AC;
24 V AC;
24 V DC;
12 V DC.
5 Safety
5.1 Electrical safety
5.1.1 General

The Road Traffic Signal System shall conform to HD 384.4. This subclause deals with the additional

requirements for Road Traffic Signal Systems.
5.1.1.1 Criteria - leakage current
5.1.1.1.1 Road Traffic Signal Systems
Class T1:

For Road Traffic Signal Systems, leakage current protection facilities conforming to HD 384.4.41 shall be

fitted. Earth leakage circuit breakers conforming to EN 61008 for nominal currents 20% greater than the

expected current and nominal leakage currents ≤ 0,3 A shall be installed.
Class T2:

No requirement for leakage current protection facilities for the whole system, however the customer may

request facilities as class T1.
5.1.1.1.2 Maintenance equipment supply
Class U0:

No requirement to provide earth leakage current protection facilities for the maintenance equipment

socket in addition to those specified above, but there may be a requirement to provide this facility when

portable tools are used.
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Class U1:

Earth leakage circuit breakers conforming to EN 61008 with nominal leakage currents ≤ 0,03 A shall be

installed.
5.1.1.2 Earthing

This subclause applies to the installation or part of the installation which is class I conforming to

IEC 60536.
5.1.1.2.1 Protective earth conductor (PE)
The system shall conform to HD 384.5.54.

Protective earth conductors shall connect together all conductive parts and the PE terminals throughout

the system. They shall either be created by conductors in a cable or by separately installed wires and/or

construction parts.

In controllers the PE conductors shall be connected to the PE terminal / earth bus bar.

NOTE Metallic bodies which, by virtue of their location or smallness, cannot be touched or are unlikely to become live shall be

designated excluded devices, i.e. they need not be connected to the PE conductor.

5.1.1.2.2 PE wiring of external equipment
NOTE 1 Examples of external equipment are poles, signal heads and detectors.
The system shall be classified according to the following methods.
Class L0:
PE wiring is not required in class II systems conforming to IEC 60536.
Class L1:

Accessible conductive parts shall be connected to the PE conductors incorporated in the cables or a

separate PE cable.

NOTE 2 Armouring of cables may also be used as PE conductors where the cable construction permits.

Class L2:

Accessible conductive parts shall be connected to a PE conductor incorporated in the cable. The signal

pole shall have an additional PE conductor in the form of a cable with a cross section of at least 10 mm

and at least 1 m longer than the cores of the cables to the distributor in the poles.

NOTE 3 Armouring of cables may also be used as PE conductors where the cable construction permits.

5.1.1.2.3 Accepted methods of earthing

Extraneous bodies shall be connected to each other by one of the following methods:

a) the connection points have been welded, reliably riveted or firmly bolted;

b) the connection points shall be established on bare metallic locations under pressure that is

maintained continuously e.g. slide-in modules.
Hinges shall have an earth bonding conductor fitted across them.

The system of earthing poles shall be classified according to the requirement for earthing and the size of

the terminal point screw for the PE conductor, as follows. The terminal point shall always be above the

ground level.
Class M1: always earthed, no screw size is specified
Class M2: earthed if required, minimum size M8
Class M3: earthed if required, minimum size M6
5.1.1.3 Enclosure

The enclosure shall provide the mechanical protection to IK07 (see EN 50102) with the following criteria:

No damage shall occur to the equipment contained within the enclosure and the equipment shall

continue to operate to it’s specification. There shall be no degradation of the IP rating of the equipment.

Class V1:

Enclosures shall provide protection to IP44. When the manual panel is open, the protection provided

shall be to IP42. When the enclosure is open the protection shall be to IP20.
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Class V2:

Enclosures shall provide protection to IP54. When the manual panel is open, the protection provided

shall be to IP43. When the enclosure is open the protection shall be to IP23.
Class V3:

Enclosures shall provide protection to IP44. When the enclosure is open the protection shall be to IP21.

Class V4:

Enclosures shall provide protection to IP55. When the manual panel is open, the protection provided

shall be to IP43. When the enclosure is open the protection shall be to IP20.
5.1.1.4 Access

Covers, doors, flaps, or similar allowing access to controls, circuits or live parts when opened, shall be

capable of being opened only with the aid of a key or a tool. Keys may be specified either on a country

basis or by the customer.
5.1.1.5 Over-current protection

Supply voltages within the enclosure or external to the enclosure shall have excess current protection,

generally by means of fuses or circuit breakers in accordance with HD 384.4.
5.1.1.6 Terminations

The system shall be classified according to its access to mains terminations as follows:

Class H0: No separate access to mains terminations.
Class H1: separate access to meters or parts of a mains terminal etc.
5.1.1.7 Controller enclosure doors

The controller enclosure shall be classified according to whether or not it is fitted with a device to lock the

doors in the open position as follows:
Class J0: No open locking device provided.

Class J1: Inspection doors shall be provided with an open locking device or simple unhinging

mechanism. The doors shall not be capable of being unhinged in the closed position.

Class J2: No open locking device provided, but the purchaser may specify the device.

5.1.2 Controller Signal outputs

The controller shall provide electrical power to the signal heads. Electrical details of compatible signal

heads shall be specified by the controller manufacturer in order to ensure the safety of the system.

NOTE The recommended voltage ranges are:
– The OPERATING VOLTAGE
– 40 V AC
– 50 V - 0 - 50 V AC
– 55 V - 0 - 55 V AC

The controller shall be classified according to the range of the current / power per signal output of the

controller, which shall include at least one or more of the following ranges:
Class K1: 0,1 A to 4 A
Class K2: 0,09 A to 2,0 A
Class K3: 0,07 A to 5 A at power factor > 0,8
Class K4: 30 VA up to 1200 VA
5.1.3 Signal heads

The signals shall use electrical power from the controller which shall be specified by the signal

manufacturer.
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NOTE The safety of the system depends on the compatibility of the signal controllers and the signal heads particularly with respect

to the signal safeguarding facilities (see 5.2.2). For example but not restricted to:

Lamps at operating mains voltage, 15 W to 200 W
Lamps at 12 W to 100 W with an associated transformer
LED signals
5.1.4 Detectors and push buttons

The general rules of this document and HD 384.4 apply. Purchasers may request for Functional Extra

Low Voltage working.
5.1.5 Interconnections
5.1.5.1 PE Terminal

The terminal points of the PE conductor on bodies shall be easily accessible and shall bear the

identification mark specified in EN 60417. They shall provide bare metallic contact and serrated washers

shall be used.
5.1.5.2 General terminations
The terminal points shall be of corrosion resisting materials.
5.1.5.3 Plugs and Sockets

Female connectors shall always be connected to the power supply and shall provide protection against

touching live parts when not interconnected.
5.1.6 Cables
5.1.6.1 PE cable dimensions
The minimum cross sections of PE conductors shall be as follows:
a) if part of a composite cable the size of the largest conductor;
b) if laid in a protected manner 2,5 mm copper;
c) if laid in an unprotected manner 4,0 mm copper.
5.1.6.2 Earth cable dimensions
The minimum cross sections of earth conductors shall be as follows:
a) if corrosion protected : 16 mm copper or galvanised steel;
b) if corrosion unprotected : 25 mm copper;
50 mm galvanised steel.
5.1.6.3 Distribution cables

Distribution cables shall be designed to work in the environment found in traffic signal systems. They

shall be of adequate cross section to withstand fault currents which may occur under fault conditions.

NOTE This is dependent on the size of the protection device, the temperature range and the insulation material.

The rating voltage of cables carrying mains voltage shall be 1000 V minimum.

The number of cores specified for the installation will depend on the facilities required.

5.2 Traffic safety
5.2.1 General

For the present subclause concerning rules for the functional safety of Road Traffic Signal Systems the

definitions for "item" and "failure" according to IEC 60050-191 shall be applied.

Failures shall be considered at different levels of the Road Traffic Signal System. Failures considered in

EN 12675 are apparent to road users, i.e. traffic and pedestrians. In this subclause those failures of items

of the Road Traffic Signal System which may lead to the faults described in EN 12675 are considered.

This subclause defines the requirements for traffic signal safety, the testing of which is defined in

clause 6.
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5.2.2 Requirements of signal intensity for safety
The signal limits for safety shall be to one of the following classes
Class AF1:

The luminous intensity of the light output on axis for signals which are required for safety to be ”ON”, e.g.

Red, shall be greater than 10 cd (as specified in EN 12368).

The luminous intensity of the light output for signals which are required for safety to be ”OFF”, e.g.

Green, shall be less than 0,05 cd (as specified in EN 12368).

The signal manufacturer shall specify the signal requirements either voltage, curren

...

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