SIST EN 50502:2016

SLOVENSKI STANDARD
01-februar-2016
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Railway applications - Rolling stock - Electric equipment in trolley buses - Safety
requirements and connection systems
Bahnanwendungen - Fahrzeuge - Elektrische Ausrüstung in O-Bussen –
Sicherheitsanforderungen und Verbindungssysteme
Applications ferroviaires - Matériel roulant - Equipement électrique des trolleybus -
Exigences de sécurité et systèmes de connexion
Ta slovenski standard je istoveten z: EN 50502:2015
ICS:
45.060.01 Železniška vozila na splošno Railway rolling stock in
general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN 50502
NORME EUROPÉENNE
EUROPÄISCHE NORM
August 2015
ICS 45.060.01 Supersedes CLC/TS 50502:2008
English Version
Railway applications - Rolling stock - Electric equipment in trolley
buses - Safety requirements and current collection systems
Applications ferroviaires - Matériel roulant - Equipement Bahnanwendungen - Fahrzeuge - Elektrische Ausrüstung in
électrique des trolleybus - Exigences de sécurité et O-Bussen - Sicherheitsanforderungen und
systèmes de connexion Verbindungssysteme
This European Standard was approved by CENELEC on 2015-03-30. 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, 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: Avenue Marnix 17, B-1000 Brussels
© 2015 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN 50502:2015 E
Contents
European foreword .4
1 Scope .5
2 Normative references .5
3 Terms and definitions .7
4 Voltages and classification of the voltage bands . 10
4.1 Voltages . 10
4.2 Classification of the voltage bands . 11
5 Trolley bus construction . 12
5.1 Protection and electrical safety criteria . 12
5.2 Electrical components in band III voltage (high voltage) . 16
5.3 Electric traction equipment . 17
5.4 Power supply independent from OCL . 18
5.5 Electrical components in band II voltage (medium voltage) . 19
5.6 Electrical components in band I voltage (low voltage) . 19
6 Checks and tests . 20
6.1 General information. 20
6.2 New trolley-vehicles . 21
6.3 Overhauled trolley-vehicles . 28
6.4 On-duty trolley vehicles (periodical checks) . 28
6.5 Leakage Detectors (overhaul, definitions, thresholds) . 29
Annex A (normative) Constructional detailed provisions . 39
A.1 General information. 39
A.2 Attachment of the current collection system and other components . 39
A.3 Insulations . 39
A.4 Ventilation . 39
A.5 Accessibility . 40
A.6 Location of the main circuit breaker . 40
A.7 Income and outlet points of cables . 40
A.8 Cabling . 40
A.9 Test terminal board . 40
A.10 Insulation leakage pre-alarm . 40
A.11 Equipment connected to different voltage band circuits . 40
A.12 Segregation of band III circuits . 40
A.13 Batteries and other energy storage devices . 41
A.14 Fuel cells . 41
A.15 Environmental conditions . 41
Annex B (normative) Trolley buses – Current collection system for overhead contact lines . 42
B.1 Scope . 42
B.2 General Characteristics . 42
B.3 Marking . 52
B.4 Checks and tests . 52
B.5 Inspections . 56
B.6 Electromagnetic compatibility . 56
Annex C (normative) Constructional requirements for current collection systems . 57
C.1 General information. 57
C.2 Material of the trolley poles . 57
C.3 Current connections . 57
C.4 Joints . 57
C.5 Cable insulation . 57
C.6 Abnormal line height . 57
Bibliography . 59

Figures
Figure 1 — Insulation overview — Trolley buses . 13
Figure 2 — Test circuits . 23
Figure 3 — Megaohmmeter connection . 26
Figure 4 — Megaohmmeter connection . 27
Figure 5 — Leakage current monitoring . 31
Figure 6 — Insulation resistance monitoring . 32
Figure 7 — Touch voltage monitoring with sliding wires . 33
Figure 8 — Touch voltage monitoring with grounded overhead contact line . 33
Figure 9 — Compensation of the voltage drop on the grounded overhead contact line . 34
Figure 10 — Voltage development with a load connected to the overhead contact line . 34
Figure 11 — Function check of the leakage current monitoring. 36
Figure 12 — Function check of the insulation resistance monitor. 37
Figure 13 — Function check of the touch voltage monitor with test against the positive of
overhead line or external voltage source . 38
Figure 14 — Function check of the touch voltage monitor with test against the positive of
overhead line or external voltage source . 38
Figure B.1 — General characteristics of a typical current collector . 42
Figure B.2 — Preferred excursion of trolley poles versus distances of contact lines to ground . 43
Figure B.3 — Example of fit of pole and the head . 45
Figure B.4 — Example of fit of mounting frame with the support base . 45
Figure B.5 – Typical trolley . 46
Figure B.6 — Typical slipper . 47
Figure B.7 — Devices (if any) for recovering and excursion limiting of pole ropes position,
overall dimensions and signalling . 50
Figure B.8 — Scheme of the verification of the detachment the current collector head . 56
Tables
Table 1 — Voltage bands for trolley buses . 11
Table 2 — Voltage bands for France . 11
Table 3 — Voltage bands for Italy (Decree D.P.R. 547: 1955, Law 191:1974) . 11
Table 4 — Voltage bands for electric plants on road vehicles . 12
Table 5 — Test voltages U based on rated insulation voltage U . 24
a Nm
Table 6 — Summary of electric tests . 29
Table B.1 — Summary of tests and checks . 53
European foreword
This document (EN 50502:2015) has been prepared by CLC/SC 9XB "Electromechanical material on
board rolling stock" of the Technical Committee CENELEC TC 9X “Electrical and electronic
applications for railways”.
The following dates are fixed:

(dop) 2016-03-30
• latest date by which this document has to be
implemented at national level by publication of
an identical national standard or by
endorsement
• latest date by which the national standards (dow) 2018-03-30
conflicting with this document have to
be withdrawn
This document supersedes CLC/TS 50502:2008.

CLC/TS 50502:2008:
- Clause 1: a more detailed scope (guided vehicles) in reference to other electric vehicles;
- 5.6.1: insulation resistance and separate source applied voltage tests for voltage band I
components is waived with respect to other electric vehicles and with reference to ECE R100;
- Table 5: test voltages for components intended to break a current which are used with open
contacts for supplementary or basic insulation;
- 6.4.2: specification of periodical checks additional to insulation resistance tests;
- 6.2.5, Table 6: electrical tests of the insulation of entrance areas are waived, visual inspection is
added;
- 6.5: extension of description and test of different leakage detectors;
- A.3: description of special requirements for external insulations;
- A.13, A.14: addition of energy storage systems and fuel cells;
- B.2.4.6: equipment for switch operation of overhead contact line.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC [and/or CEN] shall not be held responsible for identifying any or all such
patent rights.
1 Scope
This European Standard applies to electrical systems on board of vehicles of the type trolley bus, as
defined in 3.1, fed with a nominal line voltage (U ) between 600 V d.c. and 750 V d.c.
n
This European Standard defines the requirements and constructional hints, especially to avoid
electrical danger to the public and to staff. Where special requirements are existing for trolley buses,
hints are given for mechanical and functional safety as well as for protection against fire.
This European Standard covers vehicles intended for public transport of persons. This Standard
applies to:
- trolley buses,
- buses with current rail for guidance in the road surface,
- guided buses with bipolar roof current collector.
This European Standard does not apply to:
a) electric driven vehicles with only internal power supply:
1) hybrid vehicles,
2) diesel - electric vehicles,
3) fuel - cell vehicles,
4) battery vehicles,
b) vehicles with safe protective bonding:
1) rubber tyred commuter trains,
2) guided buses with supply by a separate current rail,
3) rail guided buses with unipolar roof current collector,
c) vehicles operated outside publicly accessible areas:
1) electric driven lorries on motorways.
Guidance and current rails are special solutions and at this time are not under standardization like
trolley bus current collectors and overhead contact lines (OCL).
It refers mainly to earthed networks, but reference is made also to galvanically insulated networks.
Annex A is related to detailed design features for trolley buses.
Annexes B and C are related to the current collection systems. The detailed scope of these annexes is
given in Annex B.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
EN 45502 (all parts), Active implantable medical devices
EN 45545-5, Railway applications — Fire protection on railway vehicles — Part 5: Fire safety
requirements for electrical equipment including that of trolley buses, track guided buses and magnetic
levitation vehicles
EN 50110 (all parts), Operation of electrical installations
EN 50110-1:2013, Operation of electrical installations — Part 1: General requirements
EN 50119, Railway applications — Fixed installations — Electric traction overhead contact lines
EN 50121 (all parts), Railway applications — Electromagnetic compatibility
EN 50122-1, Railway applications — Fixed installations — Electrical safety, earthing and the return
circuit — Part 1: Protective provisions against electric shock
EN 50124-1, Railway applications — Insulation coordination — Part 1: Basic requirements —
Clearances and creepage distances for all electrical and electronic equipment
EN 50125-1, Railway applications — Environmental conditions for equipment — Part 1: Rolling stock
and on-board equipment
EN 50153, Railway applications — Rolling stock – Protective provisions relating to electrical hazards
EN 50155, Railway applications — Electronic equipment used on rolling stock
EN 50163, Railway applications — Supply voltages of traction systems (IEC 60850)
EN 50178, Electronic equipment for use in power installations
EN 50215:2009, Railway applications — Rolling stock — Testing of rolling stock on completion of
construction and before entry into service
EN 50264 (all parts), Railway applications — Railway rolling stock power and control cables having
special fire performance
EN 50272-3, Safety requirements for secondary batteries and battery installations — Part 3: Traction
batteries
EN 50306 (all parts), Railway applications — Railway rolling stock cables having special fire
performance — Thin wall
EN 50343, Railway applications — Rolling stock — Rules for installation of cabling
CLC/TS 50457 (all parts), Conductive charging for electric vehicles
EN 50500, Measurement procedures of magnetic field levels generated by electronic and electrical
apparatus in the railway environment with respect to human exposure
EN 60034 (all parts), Rotating electrical machines (IEC 60034, all parts)
EN 60077 (all parts), Railway applications — Electrical equipment for rolling stock (IEC 60077, all
parts)
EN 60146 (all parts), Semiconductor converters (IEC 60146, all parts)
EN 60322, Railway applications — Electrical equipment for rolling stock — Rules for power resistors of
open construction (IEC 60322)
EN 60349 (all parts), Electric traction — Rotating electrical machines for rail and road vehicles
(IEC 60349, all parts)
EN 60445, Basic and safety principles for man-machine interface, marking and identification —
Identification of equipment terminals, conductor terminations and conductors (IEC 60445)
EN 60529, Degrees of protection provided by enclosures (IP Code) (IEC 60529)
EN 60721-3-5, Classfication of environmental conditions — Part 3: Classification of groups of
environmental parameters and their severities — Section 5: Ground vehicle installations (IEC 60721-
3-5)
EN 61111, Live working — Electrical insulating matting (IEC 61111)
EN 61287-1, Railway applications — Power converters installed on board rolling stock — Part 1:
Characteristics and test methods (IEC 61287-1)
EN 61373, Railway applications — Rolling stock equipment — Shock and vibration tests (IEC 61373)
EN 61557-2, Electrical safety in low voltage distribution systems up to 1 000V a.c. and 1 500 V d.c. —
Equipment for testing, measuring or monitoring of protective measures — Part 2: Insulation resistance
(IEC 61557-2)
EN 61557-8, Electrical safety in low voltage distribution systems up to 1 000 V a.c. and 1 500 V d.c. —
Equipment for testing, measuring or monitoring of protective measures — Part 8: Insulation monitoring
devices for IT systems (IEC 61557-8)
EN 61851 (all parts), Electric vehicle conductive charging system (IEC 61851, all parts)
EN 61881 (all parts), Railway applications — Rolling stock equipment — Capacitors for power
electronics (IEC 61881, all parts)
EN 62196-1, Plugs, socket-outlets, vehicle connectors and vehicle inlets — Conductive charging of
electric vehicles — Part 1: General requirements (IEC 62196-1)
IEC 60479 (all parts), Effects of current on human beings and livestock
ISO 6469-3, Electrically propelled road vehicles — Safety specifications — Part 3: Protection of
persons against electric shock
ISO 10099, Pneumatic fluid power — Cylinders — Final examination and acceptance criteria
ISO 16750-2, Road vehicles — Environmental conditions and testing for electrical and electronic
equipment — Part 2: Electrical loads
ISO 16750-3, Road vehicles — Environental conditions and testing for electrical and electronic
equipment — Part 3: Mechanical loads
ISO 23273, Fuel cell road vehicles — Safety specifications — Protection against hydrogen hazards for
vehicles fuelled with compressed hydrogen
3 Terms and definitions
For the purpose of this document, the following terms and definitions apply.
3.1
trolley bus
vehicles with rubber tyres (with limited lateral operating range or guided) without safe protective
bonding of the chassis, which operate with an electrical drive in the public area accessible for persons
and galvanically externally powered by a supply line (overhead contact line, current rail)
Note 1 to entry: The two poles of the supply line are either both galvanically insulated from earth or one insulated and the
other earthed. This can take place at a central point or at every feed (substation).
3.2
current collection system
whole of the components, generally mounted on the vehicle roof, having the task of taking the current
from the overhead contact lines to supply the equipment of the vehicle, both in standing and in running
conditions
3.3
mass
conductive part of an electrical component which is accessible and which is not energized in normal
conditions, but may become energized in fault conditions
Note 1 to entry: The equipment defined in 5.6.1 as normal bus vehicle components are not included in this term.
Note 2 to entry: The conductive parts of the chassis and of the bodywork are defined as the vehicle mass.
3.4
intermediate mass
conductive part between two insulating parts of a double insulated equipment (protection, enclosure,
etc.), which shall not be accessible to the public
3.5
basic insulation
insulation for personal safety between the electric parts which are subject to be energized and the
intermediate mass, to provide basic protection against electric shock
3.6
supplementary insulation
insulation for personal safety between the intermediate mass and the vehicle mass
3.7
double insulation
insulation comprising both basic insulation and supplementary insulation
Note 1 to entry: According to EN 60077-1 the basic and supplementary insulation may also be interchanged (refer also to
Table 5).
3.8
functional insulation
insulation not for personal safety, with lower requirements, that ensures the function of the plant
Note 1 to entry: To some extent, the design is specified in the product standards.
3.9
nominal voltage U
n
designated value for a system to which the general characteristics are referred
3.10
rated voltage range U
Ne
voltage range which, together with rated current, defines the use of the equipment and to which the
applicable tests and the utilization categories are referred
3.11
highest permanent voltage U
max1
maximum voltage value likely to be present indefinitely
3.12
rated insulation voltage U
Nm
value to which the dielectric test voltages and the creepage distances are referred and which can in no
cases be lower than U
Ne
Note 1 to entry: When no value is defined by the purchaser for U , the maximum operating voltage U , given by
Nm max1
EN 50163 is due to be assumed.
3.13
power frequency withstand voltage U
a
r.m.s. a.c. voltage which does not cause an insulation fault according to specified test conditions
3.14
highest non-permanent voltage U
max2
maximum voltage value likely to be present for a limited period of time
3.15
overvoltage
voltage having a peak value exceeding the corresponding peak value of maximum steady-state
voltage at normal operating conditions
3.16
long term overvoltage
overvoltage higher than U lasting typically for more than 20 ms, due to low impedance phenomena,
max2
for example a rise in substation primary voltage
3.17
highest long term overvoltage U
max3
voltage defined as the highest value of the long term overvoltage for t = 20 ms
3.18
maximum current
maximum current value which the current collection system is able to carry
3.19
maximum speed
maximum speed the vehicle can reach, to be taken into account for the current collection system to
guarantee a proper operation of the same
3.20
static contact force
→
value of force F (see Figure B.8) applied by the slipper on the contact line, as measured with standing
vehicle
Note 1 to entry: This value is referred to the mean height of the contact lines (see Figure B.2, dimension “d”), without
displacement of the vehicle from the lines axis.
3.21
dewirement
sudden and permanent detachment of the trolley of one or both poles from the overhead contact
line(s) with running trolley bus
3.22
overhead contact line
OCL
contact line which is placed above or beside the upper limit of the vehicle gauge and which supplies
traction units with electrical energy via roof-mounted current collection equipment
Note 1 to entry: The characteristics of the overhead contact line are due to be made known to the manufacturer, together
with the type of service, the environmental conditions and the road profile. Mechanical properties are given in EN 50119,
minimum heights are given in EN 50122-1.
3.23
trolley bus displacement from OCL
allowed displacement of the vehicle axis from the longitudinal contact lines axis in both transversal
directions as indicated in dimension “g” of Figure B.2
Note 1 to entry: The minimum displacement is referred to the height “d” (see Figure B.2) and represents the allowed excess
of the gauge in respect to the gauge normally allowed by the legislation.
3.24
involved parties
- manufacturer: who actually is responsible for the design and the manufacture of the vehicle;
- supplier: who acts as selling partner in a contract;
- purchaser: who acts as purchasing partner in a contract;
- operator: the final entity which is entitled to use the vehicles for public service
3.25
main contactor
remote controlled, two pole circuit breaker to connect/disconnect the entire downstream installation in
normal service mode and emergency situations
Note 1 to entry: Design also is possible with a single pole circuit breaker for one polarity combined with a single pole
follower contactor for the other polarity or a two pole fuse combined with a two pole follower contactor.
4 Voltages and classification of the voltage bands
4.1 Voltages
4.1.1 General
The voltage definitions used in this European Standard are those of EN 50163 and EN 50124-1,
where the following applies to direct voltage networks in compliance with EN 50163.
4.1.2 Operating voltages
The equipment shall operate at voltages of the overhead contact line system specified in EN 50163:
- U Nominal voltage 600 V 750 V
n
- U Rated voltage range (0.67 U to 1.2 U ) 400 V to 720 V 500 V to 900 V
Ne n n
- U Maximum permanent voltage 720 V 900 V
max1
- U Highest non permanent voltage 800 V 1 000 V < 5 min
max2
NOTE  In France, Belgium and the United Kingdom different national regulations (EN 50163) apply, which, however, do not
apply to trolley buses.
For vehicle wash plants, according to EN 50122-1 the max. allowed voltage is 120 V d.c (Voltage
band II). In this case, the vehicle wash plant is not part of the workshop where the max. allowed
voltage is 60 V d.c (voltage band I).
4.1.3 Insulation voltages and test voltages
Insulation according to EN 50124-1 shall be designed and tested with reference to the following
voltages:
- U Nominal voltage 600 V 750 V
n
- U Rated insulation voltage (≥ U ) ≥ 720 V ≥ 900 V
Nm max1
- U Power frequency withstand voltage refer to Table 5
a
4.1.4 Overvoltages
The equipment shall withstand overvoltages of the overhead contact line system specified in
EN 50163:
Nominal voltage 600 V 750 V
- U
n
- U Highest long-term overvoltage 1 270 V 1 270 V
max3
4.2 Classification of the voltage bands
According to EN 50153, the voltage bands applicable to trolley buses are in accordance with Table 1.
Table 1 — Voltage bands for trolley buses
Band Nominal voltage
a.c. V d.c. V
I U ≤ 25 U ≤ 60
N N
II 25 < U ≤ 50 60 < U ≤ 120
N N
III
50 < U ≤ 1,000 120 < U ≤ 1,500
N N
In France different limits apply because of special national conditions.
Table 2 — Voltage bands for France
Band Nominal voltage
a.c. V d.c. V
I
U ≤ 25 U ≤ 60
N N
II 25 < U ≤ 50 60 < U ≤ 120
N N
III 50 < U ≤ 500 120 < U ≤ 750
N N
IV U > 500 U > 750
N N
In Italy different limits apply because of legal regulations.
Table 3 — Voltage bands for Italy (Decree D.P.R. 547: 1955, Law 191:1974)
Band Nominal voltage
a.c. V d.c. V
I
U ≤ 25 U ≤ 50
N N
III
25 < U ≤ 400 50 < U ≤ 600
N N
IV U > 400 U > 600
N N
In ISO 6469-3 different limits apply.
Table 4 — Voltage bands for electric plants on road vehicles
Band Nominal voltage
a.c. V d.c. V
A
U ≤ 30 U ≤ 60
N N
B 30 < U ≤ 1 000 60 < U ≤ 1 500
N N
5 Trolley bus construction
5.1 Protection and electrical safety criteria
5.1.1 Protection criteria against direct and indirect contacts
The best criteria and arrangements shall be adopted in the design and in the manufacture of trolley
buses to avoid, or at least minimize to a non-dangerous level, all touch voltages and in particular the
voltage differential between mass and earth potentials and to detect leakages before the associated
voltages reach a dangerous level.
Limit values for touch voltages are specified in EN 50122-1. Limit values for shock currents are
specified in the IEC 60479 series.
NOTE  Different limit values for touch voltages apply in Switzerland (SR 734.2).
The requirements of EN 50153 shall apply wherever applicable.
Since the highest hazard potential is present when touching the outside of the vehicle, the
requirements of EN 50153 of a verifiable double insulation are supplemented by a third insulation in
the area of the doors, where passengers would be most likely to come into contact with voltages.
If possible, the double insulation should be designed such that a fault cannot bridge both paths at the
same time.
Layout of insulation distances depending on material and degree of pollution is carried out according
to EN 50124-1.
Always make sure for external insulation that part of the insulation remains protected from moisture or
dirt. If this is not possible, greater distances and/or other materials shall be selected because of the
higher minimum insulation resistances in systems with no protective bonding (see Table 6).
Figure 1 provides an overview of the double insulation requested for this vehicle type in EN 50153 as
well as of the third insulation of the doors.
The expansion of the basic insulation to double insulation always applies to all three types of
interfaces of the component:
- Supplementary insulation of the mechanical mounting;
- Supplementary insulation of the power supply module;
- Supplementary insulation of the signal interfaces.
The marking by warning signs of installation spaces containing circuits with voltages of bands II and III
or power circuits of band I shall comply with EN 50153.
Figure 1 — Insulation overview — Trolley buses
The insulation resistance of outside insulation as a factor of the atmospheric conditions and vehicles
which may have insulation defects may fall short of the limit values for personal safety.
For this reason, measures specified in this paragraph shall be taken independently of the overhead
line network configuration (earthed or galvanically isolated).
5.1.2 Steps, stanchions, handrails, slopes and access platforms
To prevent persons entering or leaving the vehicle from sensations of discharge of the vehicle mass
exceeding the threshold of perception, entrance areas shall be equipped with insulating materials as
protective impedances.
Steps, stanchions and handrails facing all doors shall be insulated from vehicle mass or made of
insulating material. Slopes and access platforms for handicapped persons shall be insulated from the
vehicle mass.
Entrance areas shall be designed with drip edges at the end of the base plate and with a drain for
ingressed water. Direct contact of surface water with other parts of the vehicle mass shall be
prevented.
The function of protective impedance of entrance areas shall be ensured by regular cleaning of the
entrance areas and visual inspection of material by qualified staff. Detergents shall be chosen to avoid
chemical wear of the material.
During visual inspection the material shall be closely examined for any damage that affects the
dielectric properties, such as fractures, cracks or pinholes (6.2.5). The dielectric properties of the
material shall comply with the requirements for basic insulation in 6.2.
A visual inspection of the cleaned entrance areas is required and is included in the periodic insulation
test procedure in 6.4.
5.1.3 Doors and door handles
All doors and relevant accessories, except for control equipment not accessible to the public, shall be
insulated from the vehicle mass or made of insulating material.
To provide sufficient creepage distances, plastic door handles or outside sliding doors without handles
are recommended.
5.1.4 Cabling
Conduits of cables fed at voltages of band III shall be segregated from those containing cables fed at
voltages of bands I and II; band III conduits and trunking shall be easily detectable by means of
suitable markings.
In case of double insulation conduits of band III cables being part of different circuits shall be
segregated according to EN 50343.
Rescue workers in cities with trolley buses and OCL are specially trained, so special labeling in classic
trolley buses with or without auxiliary power supply with diesel engine generator is not required,
because the whole system can be switched off. An exception is the cabling of energy storage devices,
which shall be labelled orange up to the first circuit breaker .
5.1.5 Open door interlocking
Traction equipment shall be provided with an interlock to prevent the vehicle from starting while the
vehicle doors are open. This interlock device shall include a push button or a similar padlocked device
enabling the driver to by-pass the feature.

see ECE Regulation No. 100.
5.1.6 Leakage detector
It is recommended, upon agreement between manufacturer and operator and matched with the supply
system, to equip trolley buses with an automatic measuring instrument, defined as a leakage detector.
Appropriate information shall be provided by the operator.
The device generates an optical/acoustic alarm signal when the insulating resistance between the
circuits fed at line voltage and the vehicle mass falls below the permissible limit values. Depending on
the type of measuring method, exceeding the permissible touch voltage or the permissible leakage
current may also be used as the criterion. The permissible insulation resistance is calculated from the
supply voltage according to EN 50163 and the threshold of feeling from the permissible shock current
specified in the IEC 60479 series.
When the above mentioned limit values have been reached, the device can open the line contactor
and lower the trolley poles automatically when the vehicle is stationary, if this feature is possible and
requested by the operator. The vehicle may feature a key switch or a similar sealable device which
enables the driver to disable the function, if the operator requests this for emergency mode. If the
vehicle has an auxiliary source of energy, it shall be used for the emergency mode.
Since the trolley poles are lowered actively and an opening of the line contactor alone cannot shut
down the entire system, safety is implemented only by the protective measure "double insulation"
supplemented by the insulation of the entrance areas.
The detection of an insulation resistance value below the permissable limit is considered to be part of
preventative maintenance. As a result this will increase the level of safety for passengers above the
level that would have been achieved by interventions only at the mandatory intervals (see also A.10).
The leakage detector or at least the relevant acoustic/optical alarm device, if any, shall be mounted at
the driving position, in a location easily visible by the driver. An external display can be agreed between
operator and manufacturer.
Where required and part of the equipment, the device may feature a means of self-diagnosis and shall
meet the resulting safety criteria. In this case, the characteristic shall be accepted by an
acknowledged authority.
Since the device itself shall feature a basic and a supplementary insulation since it is interconnected
with the system to be monitored, it may cause insulation faults itself. This shall be taken into account
especially in the design. For this reason, the device shall be included in the dielectric tests with
voltages according to Table 5 as well as in the mandatory periodic test.
5.1.7 Intermediate mass insulation detector
Where a leakage detector is provided, a device suitable to detect the insulation level of the various
intermediate masses to the relevant parts, connected to OCL, or to the vehicle mass can be installed
for preventative maintenance upon agreement between the manufacturer and the operator. This
device can be combined with the leakage detector specified in 5.1.6. The intermediate masses shall
be electrically isolated from each other (refer to Table 5).
In exceptional cases and for justified constructional reasons, some intermediate masses for
functionally homogeneous equipment may be connected with each other. In this case, the dielectric
strength between the intermediate masses according to Table 5 particularly is important.
The leakage detector of the vehicle intermediate masses facilitates preventative maintenance and can
thus increase the safety of the passengers.
5.1.8 Capacitors
For capacitors fed with voltages within band III, which may retain charge when they become
accessible to direct contact during maintenance, means shall be provided to ensure that there is no
risk of electric shock. This may be by means of integral design of discharge circuits, additional circuits
or procedure. The implementation shall be agreed between operator and manufacturer.
To achieve the best safety conditions, steps shall be taken to avoid that personnel have access
unintentionally to parts with harmful voltages. In this context, the provisions of EN 50153 and of the
EN 61881 series shall apply.
5.1.9 Equipotential connections
For insulated circuits of band III that are not directly fed from the contact wire protective measures in
compliance with EN 50153 shall be taken.
In the case of articulated trolley buses or connected coaches, these elements of the vehicle shall be
electrically interconnected, in order to have vehicle masses at the same potential. These equipotential
connections shall be easily found and suitably marked. For the identification of the connections and
the equipotential bonding circuit EN 60445 shall be applied.
5.1.10 Electromagnetic compatibility (EMC)
The electrical and electronic equipment on board shall not cause or suffer in the vehicle and in the
surrounding ambient interferences of electrical, magnetic or electromagnetic origin at such a level as
to endanger the correct operation of the control, calibration, safety, radio-transmission devices etc.,
due to emissions conducted, induced or radiated.
Field strength limits in the vehicle and in its vicinity shall not exceed the limit values of the EN 45502
series.
As a basis, the EN 50121 series with emission values in compliance with EN 50500 shall apply. For
frequencies that were not taken into account in EN 50500 with respect to human exposure the
application of 2004/40/EC is recommended.
Interference suppression measures in parallel with individual insulation distances shall not exceed the
limit values according to IEC TS 60479-2 for switching processes since these transients become
significant in the case of an insulation fault of the supplementary insulation.
Intermediate masses that may feature alternating voltage potentials by capacitive coupling shall be
wired such that the limit values according to the IEC 60479 series are not exceeded. These potentials
become significant in the case of an insulation fault of the supplementary insulation.
The operator shall also specify the critical frequencies of the existing infrastructure (to operate
switches). Interference from other systems (e.g. traffic lights) shall be considered. If necessary an
EMC plan shall be drawn up and to be agreed between manufacturer and operator.
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