SIST-TP CLC/TR 50488:2007

SLOVENSKI STANDARD
SIST-TP CLC/TR 50488:2007
01-september-2007
Železniške naprave - Varnostni ukrepi za osebje, ki dela na, ali v bližini
nadzemnega voda.
Railway applications - Safety measures for the personnel working on or near overhead
contact lines
Bahnanwendungen - Sicherheitsmaßnahmen bei Arbeiten an und in der Nähe von
Oberleitungen
Applications ferroviaires - Mesures de sécurité pour le personnel travaillant sur ou a
proximité des lignes aériennes de contact
Ta slovenski standard je istoveten z: CLC/TR 50488:2006
ICS:
13.260 9DUVWYRSUHGHOHNWULþQLP Protection against electric
XGDURP shock
45.020 Železniška tehnika na Railway engineering in
splošno general
SIST-TP CLC/TR 50488:2007 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------

TECHNICAL REPORT
CLC/TR 50488

RAPPORT TECHNIQUE
December 2006
TECHNISCHER BERICHT

ICS 13.260; 45.020


English version


Railway applications -
Safety measures for the personnel working
on or near overhead contact lines



Applications ferroviaires -  Bahnanwendungen -
Mesures de sécurité pour le personnel Sicherheitsmaßnahmen bei Arbeiten
travaillant sur ou à proximité des lignes an und in der Nähe von Oberleitungen
aériennes de contact







This Technical Report was approved by CENELEC on 2006-11-24.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Cyprus, the Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the 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


© 2006 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. CLC/TR 50488:2006 E

---------------------- Page: 2 ----------------------

CLC/TR 50488:2006 - 2 -
Foreword
This Technical Report was prepared by SC 9XC, Electric supply and earthing systems for public transport
equipment and ancillary apparatus (fixed installations), of Technical Committee CENELEC TC 9X, Electrical
and electronic applications for railways.
The text of the draft was submitted to the formal vote and was approved by CENELEC as CLC/TR 50488 on
2006-11-24.
__________

---------------------- Page: 3 ----------------------

- 3 - CLC/TR 50488:2006
Contents
Page
Introduction.4
1 Scope.5
2 Normative references.5
3 Terms and definitions .6
4 Basic principles.10
4.1 Safe operation.10
4.2 Personnel.10
4.3 Organization.11
4.4 Communication (Transmission of information).11
4.5 Work location.12
4.6 Tools, equipment and devices.12
4.7 Drawings and records.13
4.8 Signs.13
5 Standard operational procedures .13
5.1 General.13
5.2 Operating activities.13
5.3 Functional checks.14
6 Working procedures .15
6.1 General.15
6.2 Dead working.16
6.3 Live working.20
6.4 Working in the vicinity of live parts .20
7 Maintenance procedures.21
7.1 General.21
7.2 Personnel.21
7.3 Repair work.21
7.4 Temporary interruption.22
7.5 End of maintenance work.22
8 Guidance for distances in air for working procedures .22
Annex A (informative) Method of calculation of the distances in air for working procedures.23
Bibliography.25

Tables
Table 1 .5
Table 2 .22
Table A.1 .24
Table A.2 .24

Figures
Figure 1.7
Figure 2.8

---------------------- Page: 4 ----------------------

CLC/TR 50488:2006 - 4 -
Introduction
This Technical Report was prepared in order to provide a technical basis for possible further
standardization activities on the subject above.
As it is known, the safety rules for the work activities on or near electrical installations are stated by
EN 50110-1. This standard was conceived with particular reference to the A.C. three-phase or D.C.
electric power generation, transmission and distribution systems. It states explicitly that it “has not been
developed specifically to apply” to the electric traction systems, because of the particular nature of these
installations.
In developing the present document, EN 50110-1 was taken as a guide, following the recommendation
contained in the Scope of the abovementioned Standard.
Because of the too many differences existing and the particular scenarios, this document deals with
maintenance activities in the vicinities of the overhead contact lines with nominal voltage equal or above
1,5 kV.
During the WG activity the general rules for organization of the work and personnel qualification
contained in EN 50110-1 revealed to be applicable also to the electric traction lines and are reported here
for the sake of completeness. According to the CEN/CENELEC Internal Regulations Part 3 – Clause 1,
second paragraph, in the statements that were taken from EN 50110-1 without modification, the
expressions "shall", "is to" and similar were not changed in the corresponding (should, ought to, etc.)
referred to in Table G.2 of the abovementioned document.
Safety measures for live working activities are not covered in this Technical Report. In the countries
where the live working on the overhead contact lines is allowed, the National Committees should state the
necessary safety rules

---------------------- Page: 5 ----------------------

- 5 - CLC/TR 50488:2006
1 Scope
This Technical Report (TR) is applicable to all work activity on or near the overhead contact line
[IEC 60050-811, definition 811-33-02] of railway installations with supply voltage values as described in
Table 1, derived from EN 50163.
Table 1
Electrification system Nominal voltage
V
d.c. 1 500
(mean values) 3 000
a.c. 15 000
(rms values) 25 000

This Technical Report applies to requirements for safe working and maintenance procedures. It applies to
all electrical work activities as well as non-electrical work activities.
This Technical Report deals with the electrical hazard only. Risks coming from train traffic are not covered
in this document.
This Technical Report does not apply to:
 guided mass transport systems such as tramways, elevated and underground metro railways,
mountain railways, trolley bus and other conductor rail systems;
 mine or other internal industrial material transportation railways;
 railway installations with supply voltage values below 1 500 V;
 experimental electrical research work.
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 50110-1:2004, Operation of electrical installations
EN 50122-1:1997, Railway applications – Fixed installations – Part 1: Protective provisions relating to
electrical safety and earthing
EN 50163:2004, Railway applications – Supply voltages of traction systems (IEC 60850:2000, related)
IEC 60050-811:1991, International Electrotechnical Vocabulary (IEV) – Chapter 811: Electric traction
IEC 60050-826:2004, International Electrotechnical Vocabulary (IEV) – Part 826: Electrical installations

---------------------- Page: 6 ----------------------

CLC/TR 50488:2006 - 6 -
3 Terms and definitions
For the purposes of this document the following definitions apply. Refer to the International
Electrotechnical Vocabulary for other terms not defined below, like mentioned in EN 50110-1.
3.1 General
3.1.1
electric traction system
railway electrical distribution network used to provide energy for rolling stock
3.1.2
overhead contact line
contact line placed above or beside the upper limit of the vehicle gauge and supplying vehicles with
electric energy through roof-mounted current collecting equipment
3.1.3
operation
all activities including work activities necessary to permit the electrical installation to function. These
activities include such matters as switching, controlling, monitoring and maintenance as well as both
electrical and non-electrical work
3.1.4
risk
a combination of the probability and the degree of the possible injury or damage to health of a person
exposed to a hazard or to hazards
3.1.5
electrical hazard
a source of possible injury or damage to health in presence of electrical energy from an electrical
installation
3.1.6
electrical danger
risk of injury from an electrical installation
3.1.7
electrical) injury
any physical damage to a person or an animal caused by electric shock, electric burn, electricarcs, or
from fire or explosion initiated by electric energy

3.2 Personnel, organization and communication
3.2.1
nominated person in control of a work activity
that person who has been nominated to be the person with direct management responsibility for the work
activity. Parts of this responsibility may be delegated to others as required
3.2.2
nominated person in control of an electrical installation
that person who has been nominated to be the person with direct management responsibility for the
electrical installation. Parts of this responsibility may be delegated to others as required
3.2.3
skilled person
a person with relevant education and experience to enable him or her to avoid dangers which electricity
may create
NOTE  Adapted from IEC 60050-826-09-01.

---------------------- Page: 7 ----------------------

- 7 - CLC/TR 50488:2006
3.2.4
(electrically) instructed person
person adequately advised or supervised by electrically skilled persons to enable him or her to perceive
risks and to avoid hazards which electricity can create

NOTE  Adapted from IEC 60050-826-09-02.
3.2.5
ordinary person
a person who is neither a skilled person nor an instructed person
[IEC 60050-826-09-03]

3.2.6
notification
messages or instructions which are either verbal or in writing associated with operation of any electrical
installation
3.3 Working zone
3.3.1
work location
site(s), place(s) or area(s) where a work activity ìs to be, is being, or has been carried out
3.3.2
vicinity zone
limited space outside the live working zone where an electrical hazard can exist (see Figure 1 and
Figure 2)
NOTE  The outer limit of the vicinity zone is called D .
V


Figure 1

---------------------- Page: 8 ----------------------

CLC/TR 50488:2006 - 8 -

Figure 2
3.3.3
live working zone
space around live parts where prevention of electrical hazard is assured by suitable meanssuch as
limiting access to skilled persons, maintaining the appropriate air distances to energized parts and using
tools for live working (see Figure 1 and Figure 2)
NOTE  The outer limit of the live working zone is called D .
L
3.4 Working
3.4.1
work activity
any form of electrical or non-electrical work where there is the possibility of an electrical hazard
3.4.2
electrical work
work activity on or near an electrical installation such as testing and measurement, repairing, replacing,
modifying, extending, erection and inspection
3.4.3
non-electrical work
work activity near to an electrical installation such as construction, excavation, cleaning, painting, etc…
3.4.4
live working
all work activity in which a worker makes contact with live parts or reaches into the live working zone with
either parts of his or her body or with tools, equipment or devices being handled
3.4.5
working in the vicinity of live parts
all work activity in which a worker with part of his or her body, with a tool or with any other object enters
into the vicinity zone without encroaching into the live working zone

---------------------- Page: 9 ----------------------

- 9 - CLC/TR 50488:2006
3.4.6
isolation
function intended to make dead for reasons of safety all or a discrete section of the electrical installation
by separating the electrical installation or section from every source of electric energy
3.4.7
dead
at or about zero voltage that is without voltage and/or charge present
3.4.8
dead working
work activity on electrical installations which are neither live nor charged, carried out after having taken all
measures to prevent electrical danger
3.4.9
earthing
earthing is connecting the overhead contact line to the earth
3.4.10
short circuiting
short circuiting is connecting the overhead contact line to the return circuit

NOTE  Depending on the work to be performed and on the power supply system, earthing or short circuiting or both
operations may be necessary taking into account that, except than in some cases, the track of the dc systems is not
earthed.
3.5 Protective devices
3.5.1
screen
any device, which may be insulated or not, which is used to prevent approach to any equipment or part of
electrical installation which presents electrical danger
3.5.2
barrier
a part providing protection against direct contact from any usual direction of access
[IEC 60050- 826-03-13]
3.5.3
insulating covering
a rigid or flexible cover made of insulating material used to cover live and/or unenergized parts and/or
adjacent parts in order to prevent accidental contact
3.5.4
enclosure
a part providing protection of equipment against certain external influences and, in any direction,
protection against direct contact
[IEC 60050-826-03-12]
3.6
nominal voltage
designated value for a system
3.7 Distances
3.7.1
minimum working distance
distance in air to be maintained between any part of the body of a worker, or any conductive tool being
directly handled, and any part at different potentials, live or earthed. The minimum working distance is the
sum of the electrical distance and the ergonomic component

---------------------- Page: 10 ----------------------

CLC/TR 50488:2006 - 10 -
NOTE 1  In this document it is meant that the safety distances are measured from the nearest live part. For
maintenance purposes the safety distances may be measured from the live conductive part of the insulators (see
EN 50110-1 – Annex A – A.1 and A.2).
NOTE 2  The ergonomic component depends upon the type of the work to be carried out and tools.
3.7.2
electrical distance
distance in air which protects against electrical breakdown during live working. In generic terms, the
electrical component is the minimum distance between two electrodes, which represent live and/or
earthed parts, required to ensure that the probability of electrical breakdown is negligible when subjected
to the most severe electrical stress likely to arise under the conditions prescribed
3.7.3
ergonomic component
distance in air which allows for limited errors in movement and judgement of distance during the work
required to be carried out at the minimum working distance. This needs to take into consideration the
actions of the person as well as the tools that are to be used and manipulated
4 Basic principles
4.1 Safe operation
Before carrying out any operation of or work activity on or near an electrical installation an assessment of
the electrical risks shall be made. This assessment shall specify how the operation or work activity shall
be carried out to ensure safety.
4.2 Personnel
The responsibilities placed upon persons for the safety of those engaged in a work activity and those who
are or may be affected by the work activity shall be in accordance with National Legislation.
All personnel involved in a work activity on or near an electrical installation shall be instructed in the
safety requirements, safety rules and company instructions applicable to their work. These instructions
shall be repeated during the course of the work where the work is long or complex. The personnel shall
be required to comply with these requirements, rules and instructions.
Personnel shall wear clothing suitable for the locations and conditions where they are working. This could
include the use of close-fitting clothing or additional PPE.
Before any work activity is started and during that work activity, the nominated person in control of that
work activity shall ensure that all relevant requirements, rules and instructions are complied with.
The nominated person in control of the work activity shall instruct all persons engaged upon the work
activities of all dangers that are not immediately apparent to them.
No person shall undertake any work activity where technical knowledge or experience is needed to
prevent electrical danger or injury, unless that person has such technical knowledge or experience, or is
under such supervision as is necessary for the work undertaken.
National Legislation can set out the minimum age and the criteria for competence of persons.
Where there are no national requirements for competence, the following criteria shall be used in
assessing the competence of persons:
 knowledge of electricity;
 experience of electrical work;

---------------------- Page: 11 ----------------------

- 11 - CLC/TR 50488:2006
 understanding of the installation to be worked on and practical experience of that work;
 understanding the hazards which can arise during the work and the precautions to be observed;
 ability to recognize at all times whether it is safe to continue working;
 knowledge of the layout of the installation, of the special features of the overhead contact line
installations and of the special separating devices that are used in the separation zones;
 knowledge of marking the work location and of operating the earthing devices used during
maintenance activities.
The complexity of the work activity shall be assessed before the activity starts such that the appropriate
choice of skilled, instructed, or ordinary person is made for carrying out the work activity.
NOTE  Employees of the infrastructure manager or of a transport company or anyone permitted by the infrastructure
manager, not working on the catenary, are allowed to use the distances as defined by EN 50122-1 (5.1.2 and 5.1.3.2)
for non restricted areas.
4.3 Organization
Each electrical installation shall be placed under the responsibility of a person, the nominated person in
control of the electrical installation. Where two or more installations come together; it is essential that
there are formal arrangements between the nominated persons in control of each of those installations.
Access to all places where electrical hazards for ordinary persons are present shall be regulated. The
method of regulation and control of access shall be the responsibility of the nominated person in control
of the installation.
Each work activity shall be the responsibility of the nominated person in control of the work activity.
Where the work activity is subdivided it may be necessary to nominate a person to be responsible for the
safety of each subdivision, all under the responsibility of one co-ordinating person.
The nominated person in control of the work activity and the nominated person in control of the electrical
installation shall agree both the arrangements of the electrical system to allow the work to take place and
a description of the work activity on or near the electrical installation before any changes to the
arrangements of the electrical installation are made or work takes place.
The nominated person in control of the work activity and the nominated person in control of the electrical
installation can be one and the same person.
Where the work activity is complex the preparation shall be made in a written form.
A sufficient number of persons who are required to work on or near an electrical installation shall be
provided with training and information so that they are able to give appropriate first aid treatment for
electric shock and/or burns. It is recommended that guidance on first-aid is provided on posters or charts
displayed at the work location or in leaflets or safety documents issued to workers as appropriate to the
circumstances.
There shall be arrangements in place such that any worker who objects for reasons of safety to carrying
out any instruction or work activity can report those objections immediately to the nominated person in
control of the work activity. That nominated person shall have the matters investigated, and if necessary
consult a higher authority for a decision.
4.4 Communication (Transmission of information)
This includes every way in which information is passed or exchanged between persons i.e. by spoken
word (including telephone, personal radio, and person to person), in writing (including fax), and visually
(including Visual Display Units, annunciator panels, lights etc.).

---------------------- Page: 12 ----------------------

CLC/TR 50488:2006 - 12 -
Before any work activity starts, the nominated person in control of the electrical installation shall be
informed of the intended work.
All necessary information such as network arrangements, the status of switchgear (on, off, earthed), and
the position of safety devices, to permit safe operation of the electrical installation shall be transmitted by
a notification. Where it is necessary to use other means of transmitting information, for example radio
signals, computers, lights, etc. such means shall only be used when precautions are taken and are in
place to ensure that the information path is reliable and that no misunderstandings can arise or false
signals are given.
All notifications shall include the name and if necessary, the location of the person providing the
information.
To avoid errors when information is transmitted verbally the recipient shall repeat the information back to
the sender, who shall confirm it has been correctly received and understood. Permission to start work and
re-energizing of the electrical installation on completion of work which is controlled by signals or pre-
arranged understanding after an agreed interval of time shall not be permitted.
NOTE  A good practice could be to use the phonetic alphabet for critical communications.
4.5 Work location
The work location shall be defined and marked clearly. Adequate working space, means of access and
lighting shall be provided at all parts of an electrical installation on or near which any work activity is to be
carried out. When necessary the access to the work location shall be marked clearly in outdoor
installations.
Overhead contact lines are always installed in a direct reference to a track of the railway infrastructure but
singular points also exist. So for overhead contact lines the track, in which the work activity takes place,
the earthing devices and the insulators in the catenary are normally sufficient to mark the work location in
plain line situation.
Suitable precautions shall be taken to prevent injury to persons from other sources of danger such as
mechanical or pressure systems or falls.
Objects which impede access and/or flammable materials shall not be placed adjacent to nor in or on
access ways, escape routes to and from electrical switchgear and controlgear nor in those areas where
personnel have to operate that equipment. Flammable materials shall be kept out of electric arc sources.
In railway stations with a lot of tracks, switches and a complex arrangement of the overhead contact line
as well as in the interconnections, if there are crossings and in the stretches of line where the installations
differs from the simple line configuration (for instance: regulations) additional signs should be used (eg
flag, or railway markers) in order to limit the movements of on track vehicle.
4.6 Tools, equipment and devices
Tools, equipment and devices shall comply with the requirements of relevant European, International or
National Standards where these exist.
NOTE 1  Examples of tools, equipment and devices are:
 insulating boots, gloves and overshoes;
 eye or face protection;
 head protection;
 suitable protective clothing;
 insulating mats, platforms and stands;
 insulating flexible and rigid screening materials;

---------------------- Page: 13 ----------------------

- 13 - CLC/TR 50488:2006
 insulated and insulating tools;
 operating poles and rods;
 locks, notices, signs;
 voltage detecting and indicating devices;
 cable locating equipment;
 earthing and short-circuiting equipment;
 barriers, flags, supports.
Tools, equipment and devices shall be used in accordance with the instructions and/or guidance provided
by the manufacturer or supplier. These instructions and/or guidance shall be in the language or
languages of the country of use.
Any tools, equipment and devices provided for the purpose of safe operation of, or work on or near
electrical installations shall be suitable for that use, be maintained in a condition suitable for that use, and
be properly used.
NOTE 2  "Maintained in a condition suitable for use" means periodic visual inspections and electrical testing where
necessary including after repairs and /or modification to verify the electrical integrity and mechanical properties of the
tools, equipment and devices.
NOTE 3  Equipment includes personal protective equipment.
All special tools, equipment and devices used during operation of, or work on
...