SIST-TS CLC/TS 50502:2008

SLOVENSKI STANDARD
01-oktober-2008
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SIST-TS CLC/TS 50502:2007
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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: CLC/TS 50502:2008
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.

TECHNICAL SPECIFICATION
CLC/TS 50502
SPÉCIFICATION TECHNIQUE
July 2008
TECHNISCHE SPEZIFIKATION
ICS 45.060.01 Supersedes CLC/TS 50502:2007

English version
Railway applications –
Rolling stock –
Electric equipment in trolley buses –
Safety requirements and connection systems

Applications ferroviaires –  Bahnanwendungen –
Matériel roulant – Fahrzeuge –
Equipement électrique des trolleybus – Elektrische Ausrüstung in O-Bussen –
Exigences de sécurité et systèmes Sicherheitsanforderungen
de connexion und Verbindungssysteme

This Technical Specification was approved by CENELEC on 2008-05-09.

CENELEC members are required to announce the existence of this TS in the same way as for an EN and to
make the TS available promptly at national level in an appropriate form. It is permissible to keep conflicting
national standards in force.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, 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

© 2008 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. CLC/TS 50502:2008 E
Foreword
This Technical Specification was prepared by SC 9XB, Electromechanical material on board rolling
stock, of Technical Committee CENELEC TC 9X, Electrical and electronic applications for railways.
The text of the draft was submitted to vote in accordance with the Internal Regulations, Part 2,
Subclause 11.3.3.3 and was approved by CENELEC as CLC/TS 50502 on 2008-05-09.
This Technical Specification supersedes CLC/TS 50502:2007.
The following date was fixed:
– latest date by which the existence of the CLC/TS
has to be announced at national level (doa) 2008-11-09
__________
– 3 – CLC/TS 50502:2008
Contents
1 General . 4
1.1 Scope . 4
1.2 Normative references . 4
1.3 Definitions . 5
1.4 Voltages . 7
1.5 Classification of the voltage bands . 7
2 Trolley bus construction . 8
2.1 Protection and electrical safety criteria . 8
2.2 Electrical components in band III voltage (high voltage) . 10
2.3 Electric traction equipment . 10
2.4 Emergency running equipment (independent from OHL) . 11
2.5 Electrical components in band II voltage (medium voltage) . 12
2.6 Electrical components in band I voltage (low voltage) . 12
3 Checks and tests . 13
3.1 General . 13
3.2 New trolley-vehicles . 13
3.3 Overhauled trolley-vehicles . 19
3.4 On-duty trolley vehicles (periodical checks) . 20
3.5 Le ak ag e d et ec tors . 20
Annex A (normative) Constructional detailed provisions . 23
Annex B (normative) Trolley buses – Connection system to overhead
contact lines. 25
Annex C (normative) Constructional hints for connection systems . 40
Bib lio gr ap h y . 41
Figures
Figure 1 – Test circuits . 14
Figure 2 – Megaohmmeter connection . 17
Figure 3 – Megaohmmeter connection . 18
Figure 4 – Typical efficiency verification criteria for the leakage detector . 21
Figure B.1 – General characteristics of a typical current collector . 25
Figure B.2 – Preferred excursion of trolley poles versus distances of contact lines to
gr o u nd . 26
Figure B.3 – Example of coupling of rod with this head and underbase . 28
Figure B.4 – Typical trolley . 29
Figure B.5 – Typical slipper . 30
Figure B.6 – Devices (if any) for recovering and excursion limiting of rod ropes
position, overall dimensions and signalling . 33
Figure B.7 – Scheme of the verification of the slipping off of the current collector head . 38
Tables
Table 1 – Voltage bands for trolley buses . 8
Table 2 – Test voltages U based on rated insulation voltage U . 16
a Nm
Table 3 – Calibration of the insulation resistance . 21
Table 4 – Summary of electric tests . 22
Table B.1 – Summary of tests and checks . 35

1 General
1.1 Scope
This Technical Specification applies to electrical systems on board trolley buses, as defined in 1.3.1,
fed with a nominal line voltage (U ) between 600 V d.c. and 750 V d.c.
n
This Technical Specification defines the requirements and constructional hints, especially to avoid
danger of electrical kind to the public and to the personnel.
CLC/TS 50502 is normative only for vehicles ordered and designed after publication of the same.
This Technical Specification covers vehicles intended for public transport of persons.
It refers mainly to earthed networks, but reference is made also to galvanically insulated networks.
Annexes B and C are related to the connection systems. The detailed scope of these annexes is given
in Annex B.
1.2 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 45 Definition of weldability
EN 50119 Railway applications – Fixed installations – Electric traction overhead contact lines
EN 50121 series Railway applications – Electromagnetic compatibility
EN 50122-1 Railway applications – Fixed installations
Part 1: Protective provisions relating to electrical safety and earthing
EN 50124 series Railway applications – Insulation coordination
EN 50125 series Railway applications – Environmental conditions for equipment
EN 50153 Railway applications – Rolling stock – Protective provision relating to electrical
hazards
EN 50155 Railway applications – Electronic equipment used on rolling stock
EN 50163 Railway applications – Supply voltages of traction systems
1)
EN 50207 Railway applications – Electronic power converters for rolling stock
EN 50215 Railway applications – Testing of rolling stock after completion of construction and
before entry into service
1)
Superseded by EN 61287-1.
– 5 – CLC/TS 50502:2008
EN 50264 series Railway applications – Railway rolling stock cables having special fire
performance – Standard wall
EN 50272-3 Safety requirements for secondary batteries and battery installations
Part 3: Traction batteries
EN 50306 series Railway applications – Railway rolling stock cables having special fire
performance – Thin wall
EN 50343 Railway applications – Rolling stock – Rules for installation of cabling
EN 60077 series Railway applications – Electrical equipment for rolling stock
(IEC 60077 series, mod.)
EN 60322 Railway applications – Electrical equipment for rolling stock – Rules for power
resistors of open construction (IEC 60322)
EN 60349-1 Electric traction – Rotating electrical machines for rail and road vehicles
Part 1: Machines other than electronic convertor-fed alternating current motors
(IEC 60349-1)
EN 60349-2 Railway applications – Rotating electrical machines for rail and road vehicles
Part 2: Electronic converter-fed alternating current motors (IEC 60349-2, mod.)
EN 61373 Railway applications – Rolling stock equipment – Shock and vibration tests
(IEC 61373)
EN ISO 9001 Quality management systems – Requirements (ISO 9001)
ISO 10099 Pneumatic fluid power – Cylinders – Final examination and acceptance criteria
1.3 Definitions
For the purposes of this document, the following terms and definitions apply.
1.3.1
trolley bus
rubber tyred vehicle, connected to a direct current overhead contact line, driven by one or more
electrical motors. The conductors of the overhead contact line are either both insulated or one
insulated and one earthed
1.3.2
current collection system
the whole of the components, generally mounted on the vehicle roof, having the task of taking the
current from the overhead lines to supply the equipment of the vehicle, both in standing and in running
conditions
1.3.3
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; the equipment defined in 2.6.1 as normal
bus vehicle components are not covered in this definition. The conductive parts of the chassis and of
the bodywork are defined as the vehicle mass

1.3.4
intermediate mass
conductive part comprised between two insulating parts of a double insulated equipment (protection,
enclosure, etc.), which shall be in any case not accessible to the public
1.3.5
main insulation
insulation between the electric parts which are subject to be energized and the intermediate mass
NOTE In EN 50124-1 this insulation is named “basic insulation” and is defined as the insulation applied to live parts to provide
basic protection against electric shock.
1.3.6
supplementary insulation
insulation between the intermediate mass and the vehicle mass
1.3.7
double insulation
insulation comprising both main (basic) insulation and supplementary insulation
1.3.8
nominal voltage U
n
voltage value with which the system or one part of the same is nominated and which the general
characteristics are referred to
1.3.9
rated voltage U
Ne
voltage which, together with rated current, defines the use of the equipment and which the applicable
tests and the use categories are referred to
1.3.10
rated insulation voltage U
Nm
value the dielectric test voltages and the creepage distances are referred to. In no cases this value
can be lower than U . When no value is defined by the purchaser for U , the maximum operating
Ne Nm
voltage U , given by EN 50163 shall be assumed
max1
1.3.11
power frequency withstand voltage U
a
r.m.s. a.c. voltage which does not cause an insulation fault according to specified test conditions
1.3.12
highest non-permanent voltage U
max2
maximum value of the voltage likely to be present for maximum 5 min
1.3.13
maximum current
maximum current value which the current collection system is able to carry
1.3.14
maximum speed
maximum speed the vehicle can reach, to be taken into account for the connection system to
guarantee a proper operation of the same
1.3.15
static contact force
→
value of force F (see Figure B.7) applied by the slipper on the contact line, as measured with standing
vehicle. 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

– 7 – CLC/TS 50502:2008
1.3.16
dewirement
the accidental and permanent detachment of the trolley of one or both poles from the overhead
contact line(s) with running trolley bus
1.3.17
overhead contact lines (OHL)
the fixed equipment intended to supply the power to the vehicle. The characteristics of the OHL shall
be made known to the tenderer, together with the type of service, the environmental conditions and
the road profile
1.3.18
trolley bus displacement from OHL
the 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
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
1.3.19
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
1.3.20
main contactor
a remote controlled, two pole circuit breaker to connect/disconnect the entire downstream installation
in normal service mode and emergency situations
1.4 Voltages
The voltage definitions used in the Technical Specification are those of EN 50163 and EN 50124-1,
where:
• U nominal voltage 600 V d.c. 750 V d.c.
n
• U rated voltage (0,67 U to 1,2 U) 402÷720 V d.c. 502,5÷900 V d.c.
N n n
• U rated insulation voltage (≥ U ) ≥ 720 V d.c. ≥ 900 V d.c.
Nm max1
• U maximum applicable voltage 800 V d.c. 1 000 V d.c.
max2
• U power frequency withstand voltage see Table 2
a
1.5 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 Rated voltage
a.c. d.c.
V V
I U ≤ 25
≤ 60
N
II 25 < U ≤ 50 60 < U ≤ 120
N N
III
50 < U ≤ 1 000 120 < U ≤ 1 500
N N
NOTE In France and Italy different limits apply because of legal prescriptions.
2 Trolley bus construction
2.1 Protection and electrical safety criteria
2.1.1 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 minimise to a non-dangerous level, all contact voltages and in particular the
voltage differential between mass and earth potentials and to detect leakages before the associated
voltages reach a dangerous level. As reference, the requirements of EN 50153 apply for similar
features.
Provisions of this paragraph are independent from the overhead line network configuration (earthed
or galvanically insulated).
2.1.2 Steps, handrails, slopes and access platforms
Steps and handrails facing all doors shall be insulated from vehicle mass or made of insulating
material. Slopes and access platforms intended to assist handicapped people, shall be insulated from
the vehicle mass. Alternatively when it is not insulated from mass the operation shall be interlocked
with opening the main line contactor.
2.1.3 Doors
All door shutters and relevant accessories, except for control equipment not accessible to the public,
shall be insulated from the vehicle mass or made of insulating material.
2.1.4 Cabling layout
Canalisation 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 canalisations shall be easily detectable by means of suitable
markings. In case of double insulation canalisation of band III cables being part of different circuits
shall be segregated according to EN 50343.

– 9 – CLC/TS 50502:2008
2.1.5 Open door interlocking
Traction equipment shall be provided with an interlock to prevent the vehicle from starting while the
doors are open. This interlock device shall include a push button or a similar padlocked device
enabling the driver to exclude the feature. Directive 2001/85/EC shall be complied.
2.1.6 Leakage detector
When the feature is applicable, trolley buses shall be equipped with an automatic safety device,
defined as leakage detector. The device gives an optical/acoustic alarm signal when the insulating
resistance, between the circuits fed at line voltage and the vehicle mass, decreases down to
unacceptable limits such as those mentioned in EN 50153 or the vehicle body potential reaches the
limits given in EN 50122-1.
When the above mentioned limit value is reached, the device actuates, when the vehicle is standing,
the line contactor circuit breaker to open and the contact rods to lower automatically, when this feature
is possible.
The leakage detector or at least the relevant acoustic/optic alarm device, if any, shall be mounted at
the driving place, in a location easily visible by the driver.
The device, when required and supplied, shall be provided with self-checking means and shall satisfy
intrinsic safety criteria; an authorized third party shall verify, in this case, the characteristics.
2.1.7 Intermediate mass insulation detector
In case of a leakage detector is provided, a device suitable to detect the insulation level of the various
parts energised towards the relevant intermediate masses and towards the vehicle mass shall be
provided on request. This device may be combined with the leakage detector described in 2.1.6. The
intermediate masses shall be electrically insulated among themselves (see Table 2); it is allowed that,
exceptionally and for justified constructional reasons, some intermediate masses of functionally
homogeneous equipment are connected.
2.1.8 Capacitors
The capacitors fed with voltages within band III shall be provided with discharge resistances in
parallel. To achieve the best safety conditions, steps shall be taken to avoid that personnel have
access unintentionally to parts with harmful voltages. In this connection reference shall be made to the
requirements given by EN 50153.
2.1.9 Equipotential connections
In case of articulated trolley bus or connected coaches, these elements of the vehicle shall be
electrically interconnected, in order to have vehicle masses at the same potential. These connections
shall be easily found and suitably marked.
2.1.10 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.
Reference shall be made to EN 50121 series.

2.2 Electrical components in band III voltage (high voltage)
2.2.1 General
The electrical components fed at a voltage of band III and connected to the OHL shall be specifically
made for electric traction, suitable for use in trolley bus service, with the pole terminals isolated from
intermediate mass.
For the electrical and mechanical characteristics the specific standards for the specific product apply.
2.2.2 Current collection system
See Annex B.
2.2.3 Cables
Cable shall have characteristics for fire of non-propagating flame, reduced smoke, toxic and corrosive
gases emissions. They shall comply with the European Standards (see EN 50343, EN 50264 and
EN 50306) as applicable for these types of traction cables when applied on trolley buses.
2.2.4 Auxiliary groups
The auxiliary groups fed at the line voltage, e.g. the auxiliary motors for driving the compressor, the
fans, the hydroguide pump, etc., the auxiliary generators, the static converters, and so on, shall have a
double insulation in respect to the vehicle mass, independent from the overhead line network
configuration (earthed or galvanically insulated).
The equipment supplied through circuits galvanically insulated from the line may be mounted without
the double insulation.
Protective provisions against electrical hazard shall be in accordance with EN 50153 for insulated
supply systems.
2.2.5 Climatisation devices
When space heaters or air conditioning equipment, for different uses, imply components supplied by
band III voltages, the requirements given in 2.2.4 apply. Ventilation ducts, if made of conducting
material, shall be connected to the vehicle mass.
2.3 Electric traction equipment
2.3.1 General
The electrical traction equipment mainly comprises the traction motor(s), the driving equipment for the
operation and the braking, the resistor, if any, for starting and braking.
The control and the calibration equipment are considered part of the traction equipment on the
functional point of view.
– 11 – CLC/TS 50502:2008
2.3.2 Traction motors
For the traction motors EN 60349 series apply.
The motors shall be arranged to have a double insulation both in respect to the fixing to the chassis
and to the connection to the transmission outputs.
2.3.3 Traction and braking drive
EN 50207 applies to the electronic power equipment.
EN 60077 series applies in case of electromechanical drive.
EN 50155 applies to electronic control equipment.
The equipment shall be installed in body compartments or enclosures, suitably ventilated and
accessible only to the personnel attending the trolley buses. All the live parts shall have double
insulation in respect to the vehicle mass, except for those galvanically insulated from the line voltage,
and shall be in any case protected from undue accidental contacts when excited.
2.3.4 Starting and braking resistors
EN 60322 applies to the electrical resistors. They shall be mounted in order to have the live parts with
double insulation against the vehicle mass and with suitable barriers or arrangements for protection
from undue accidental contacts when excited.
When the heat produced by the resistors is used for heating the ambient, the relevant conduits, if
made of conducting material, shall be electrically connected to the vehicle mass.
2.4 Emergency running equipment (independent from OHL)
2.4.1 General
Trolley buses may be equipped with an equipment for running with an auxiliary source of electrical
energy, differing from the overhead contact line.
This equipment may be an electro generating thermal engine, a group of batteries or other equivalent
mean suitable to supply the traction motor(s).
As far as the control and safety systems are concerned, they can remain in use as in normal running.
2.4.2 Independence of emergency equipment and insulation requirements
All electrical components for specific use for the operation in independent running shall have the same
characteristics as required for equipment fed at the same voltage band.
Except for special features, any electrical connection between overhead contact line and the electrical
source for independent running shall be excluded without the need of lowering the contact rods. In this
case double insulation is not required, but intermediate test connection has to be defined between
purchaser and supplier.
The equipment under 2.3.1 may be used for feeding the traction motor(s).

2.5 Electrical components in band II voltage (medium voltage)
2.5.1 General
The electrical components supplied at a voltage of band II shall be two-pole and insulated from the
vehicle mass. They shall be protected by means of fuses or automatic breakers having a suitable
breaking capacity and they shall be suitable for the use on trolley buses. When there is the need of
having on the vehicle components fed at voltages pertaining to different bands, suitable arrangements
shall be taken for an effective electrical segregation.
Protective provisions against electrical hazards shall be according EN 50153 for insulated supply
systems.
2.5.2 Cables
The cables for the circuits at a voltage of band II shall be of the type non-propagating flame, at low
emission of smokes and toxic or corrosive gases. The cables shall comply with the European
Standards for traction cables of the above-mentioned characteristics for use on trolley buses (see
EN 50343, EN 50264 and EN 50306).
2.5.3 Separation from other voltage band circuits
The circuits related to the components under 2.5.1, which are mounted on the same structures with
cables for voltages of bands I and III, shall be designed for a suitably segregated installation. The
connection points, if any, of cables for voltages in band II and apparatus at voltages in bands I and III,
shall be carefully designed in respect to distance, mechanical protection and insulation between
voltages.
2.6 Electrical components in band I voltage (low voltage)
2.6.1 General
Protective provisions against electrical hazards shall be according to EN 50153 for insulated supply
systems.
The electrical components supplied at a voltage of band I are shared between two groups as follows:
• Trolley bus components: components specifically designed for trolley buses, such as the
traction control, the auxiliary services, etc. for which it is possible also the presence of circuits fed
with voltages of band III. The components having a simple insulation against the line voltage shall
be two-pole and fed through a galvanic separation device suitable for an insulation equal to that
between intermediate mass and vehicle mass of the line fed equipment (see Table 1). An
intermediate connection for insulation check has to be agreed between purchaser and supplier.
Electronic components used in connection with band II and III equipment can be handled as
required in the following Item “normal bus components”.
• Normal bus components: components used in any bus, such as the internal and external lighting
systems, signalling, diesel engines for driving the vehicle and APU and relevant starters. These
may be single-pole with the return connected to the trolley bus mass directly or indirectly (cabled
negative), according to the requirements and to the constructional needs.
They shall be protected by means of fuses or automatic breakers having a suitable breaking capacity
and they shall be suitable for the use on trolley buses. When there is the need of having on the vehicle
components fed at voltages pertaining to different bands, suitable arrangements shall be taken for an
effective electrical segregation.

– 13 – CLC/TS 50502:2008
2.6.2 Cables
The application of the requirements under 2.5.2 is subject to agreement between purchaser and
supplier. See also EEC and EN 45.
2.6.3 Separation from other voltage band circuits
See 2.5.3.
3 Checks and tests
3.1 General
The requirements contained in this clause concern the dielectric tests to be carried out specifically on
trolley bus equipment. Test on components are specified in the relevant product standards and
applied.
The additional applicable tests according to this Technical Specification are listed in Table 2.
Checking of the insulation shall be carried out at least at three month intervals from 15 000 km to
30 000 km (as stated by the operator) of operation, considering the limit firstly encountered between
the two given above. These limits can be shortened in case the pre-alarm device mentioned in A.10 is
present and the readings suggest frequent insulation checks.
Hereafter the limit values for the insulation are given for a new trolley bus, for an overhauled trolley
bus and for a trolley bus during normal service.
NOTE In Italy and Switzerland different limits apply because of legal prescriptions.
3.2 New trolley-vehicles
3.2.1 Design and construction verification
The compliance of the vehicle to the requirements of Clause 2 shall be carefully verified, particularly in
respect to the insulation of the equipment having voltages in band III, especially those circuits fed by
the OHL with double insulation.
The design shall list and show the various intermediate masses, on which the electrical tests below
specified shall be carried out.
3.2.2 Separate source applied voltage tests on circuits and components fed at voltages of
the band III
Circuits and electrical components at the line voltage and those fed at voltages of the band III, with
double insulation against the vehicle mass, shall be submitted to voltage tests, carried out on new
material when the vehicle is commissioned according to EN 50215.
The test is carried out:
a) after having excluded the motors and those components supplied at voltages of band III which
could be damaged or could disturb the test and having connected all remaining circuits, belonging
to one insulation level of band III. A list of such components shall be given as well as
documentation of a separate test carried out by the manufacturer;

b) having connected to earth all remaining circuits and components of the electrical equipment of
the trolley bus;
c) by applying gradually during 10 s a test voltage U a.c., sinusoidal, at a frequency of 50 Hz and
a
keeping this value for a duration of 60 s; U is shown in Table 2;
a
d) by carrying out the test between the above mentioned circuits and components and the
intermediate masses connected together and to the vehicle mass (see Figure 1 a));
e) by repeating the test between the intermediate masses connected and the vehicle mass (see
Figure 1 b));
f) by repeating the test between the intermediate masses kept insulated.
The circuits and the components fed at voltages of band III, but not fed directly by the voltage of the
line and not provided with double insulation towards mass, shall be tested as above, at a voltage U
a
(see Table 2), applied between the concerned circuits and the vehicle mass.
If a dielectric test failed the second test after repair shall be carried out at 85 % of U .
a
Figure 1 a) Figure 1 b)
Key
(a) circuit or electrical component  (d) voltage generator
(b) intermediate mass  (e) equipotential connection
(c) vehicle mass
Figure 1 – Test circuits
3.2.3 Separate source applied voltage tests on circuits and components fed at voltages of
the band II
The circuits and the components supplied at voltages of band II shall be submitted to voltage test, on
new material, when the vehicle is commissioned according to EN 50215.
The test is carried out:
a) after having excluded those components supplied at voltages of band II which could be damaged
or could disturb the test and having connected all remaining circuits, belonging to one insulation
level of band II;
b) having connected to earth all remaining circuits and components of the electrical equipment of
the trolley bus;
c) by applying gradually during 10 s a test voltage U a.c., sinusoidal, at a frequency of 50 Hz and
a
keeping this value for a duration of 60 s, between said circuits and components and the vehicle
mass; U is shown in Table 2.
a
– 15 – CLC/TS 50502:2008
3.2.4 Separate source applied voltage tests on circuits and components fed at voltages of
the band I
Circuits and electrical components supplied at voltages of the band I shall be submitted to voltage
tests, carried out on new material when the vehicle is commissioned according to EN 50215.
The test is carried out:
a) after having excluded the components supplied at voltages of band I which could be damaged or
could disturb the test and having connected all remaining circuits, belonging to one insulation
level of band I;
b) having connected to earth all remaining circuits and components of the electrical equipment of
the trolley bus;
c) by applying gradually during 10 s a test voltage U a.c., sinusoidal, at a frequency of 50 Hz and
a
keeping this value for a duration of 60 s between the concerned circuits and the vehicle mass; U
a
is shown in Table 2.
The circuits and the components fed at voltages of band III, but not fed directly by the voltage of the
line and not provided with double insulation towards mass, shall be tested as above, at a voltage U
a
(see Table 2), applied between the concerned circuits and the vehicle mass.

Table 2 – Test voltages U based on rated insulation voltage U
a Nm
Subject Industrial frequency applied voltage U
a
V
Rated insulation voltage U
Nm
> 36 > 60 > 300 > 660
≤ 36
≤ 60 ≤ 300 ≤ 660 ≤ 1 200
For components with single insulation, dielectric
2 U +
test shall be carried out across any circuit supplied Nm
750 1 000 1 500 2 500
to a given voltage and the mass, to which all the 1 500
remaining circuits shall be connected
For components with single insulation which are
not connected to OHL, dielectric test shall be
2 U + 1 500
Nm
carried out across any circuit supplied to a given 750 1 000 2 000
min. 1 500 V
voltage and the mass, to which all the remaining
circuits shall be connected
For components with double insulation, the
dielectric test shall be made:
1,6 U +
Nm
1 500 1 500
• across intermediate masses connected and
the vehicle mass and across each pair of
intermediate masses when insulated
• across an electrode put in contact to platform,
doors or handicapped people ramps and
vehicle mass
• across the circuits and the intermediate
2 U +
Nm
2 000 2 500
masses connected to the vehicle mass
1 500
NOTE  Where the main insulation is provided between
intermediate masses and vehicle mass, the test voltages
are to be reversed
NOTE For electronic equipment with U < 36 V the dielectric test voltage is reduced to 500 V.
Nm
NOTE Table 2 is drawn out from EN 60077-1 and is adapted to circuits and components in use on board trolley-vehicles.
3.2.5 Insulation resistance values for circuits and components supplied at the line voltage
The following insulation resistance measurements shall be effected:
a) between the vehicle mass and all the interconnected circuits and components supplied at the line
voltage (see Figure 2 a);
b) between each intermediate mass and all the interconnected circuits and components supplied at
the line voltage (see Figure 2 b);
c) between the vehicle mass and each intermediate mass (see Figure 2 c);
d) between each intermediate mass and all other intermediate masses.
The tests, to be performed with the modalities shown in 3.2.6 (dry conditions), are considered
successful when the insulation resistance, measured and expressed in Megaohms, satisfies the
condition:
R ≥ 4 + U / 300
Nm
NOTE Internal regulations (e.g. in Switzerland) may impose tests relating to wet conditions.

– 17 – CLC/TS 50502:2008
3.2.6 Insulation resistance test modalities for circuits and components supplied at the line
voltage
The insulation tests shall be made with the vehicle dry. Referring to the tests under a) and b) of 3.2.5,
all circuits and electrical components shall be connected; therefore, considering the electrical diagram
of the vehicle equipment, all switches and contactors concerned shall be in the position to put all parts
of the electrical installation directly supplied at the line voltage energised during the test.
Before testing, the mass connection of the leakage detector (see 2.1.6) shall be removed.
The measure shall be carried out with a megaohmmeter with a generator (part of the instrument) for
1 000 V d.c.
According to the measurement type the megaohmmeter shall be connected as indicate in Figure 2 a),
b) or c).
Figure 2 a)
Figure 2 b) Figure 2 c)
Key
(a) circuit or electrical component
(b) intermediate mass
(c) trolley bus mass
(d) measuring instrument
Figure 2 – Megaohmmeter connection
3.2.7 Insulation resistance values for circuits and components supplied at a band III voltage
differing from the line voltage
These circuits and electrical components shall be submitted to the measurement of the insulation
resistance against the vehicle mass. The test is considered successful when the insulation resistance,
measured in dry conditions and expressed in Megaohms, satisfies the condition:
R ≥ 4 + U / 300
Nm
NOTE Internal regulations (e.g. in Switzerland) may impose tests relating to wet conditions.

When an intermediate mass is present for constructional reasons in these installations, the criteria
shown in 3.2.5 b) and c) apply. The resistance values for these intermediate masses shall satisfy the
above-mentioned condition.
The insulation tests shall be made with the vehicle dry. All circuits and electrical components shall be
connected; therefore, considering the electrical diagram of the vehicle equipment, all concerned
switches and contactors shall be in the position to put all parts of the electrical installation supplied at
the voltage of band III energised during the test.
Before testing, the mass connection of the leakage detector (see 2.1.7) shall be removed.
The measure shall be carried out with a megaohmmeter with a generator (part of the instrument) for
1 000 V d.c.
The megaohmmeter shall be connected as indicated in Figure 3.

Key
(a) circuit or electrical component
(c) trolley bus mass
(d) measuring instrument
Figure 3 – Megaohmmeter connection
When intermediate masses are present, the instrument shall be connected as shown in Figure 2 b)
and c).
Depending on the provisions (according EN 50153) to prevent electrical hazards, if applicable, the
insulation test can be included in the periodical insulation test.
3.2.8 Insulation resistance values for circuits and components supplied at a voltage of band II
The insulation resistance between the vehicle mass and all the interconnected circuits and
components supplied at a voltage of band II shall be measured.
The test, to be performed according the modalities shown in 3.2.9 is considered successful when the
insulation resistance, measured and expressed in Megaohms, is equal to or exceeding 4 MΩ.

– 19 – CLC/TS 50502:2008
3.2.9 Insulation resistance test modalities for circuits and components supplied at a voltage of
band II
The insulation tests shall be made with the vehicle dry. All circuits and electrical components shall be
connected; therefore, considering the electrical diagram of the vehicle equipment, all concerned
switches and contactors shall be in the position to put all parts of the electrical installation supplied at
the voltage of band II energised during the test.
Before testing, the mass connection of the leakage detector (see 2.1.7) shall be removed.
The measure shall be carried out with a megaohmmeter with a generator (part of the instrument) for
1 000 V d.c.
The megaohmmeter shall be connected as indicated in Figure 3.
Depending on the provisions (according EN 50153) to prevent electrical hazards, if applicable, the
insulation test can be included in the periodical insulation test.
3.2.10 Insulation resistance values for circuits and components supplied at a voltage of band I
The insulation resistance between the vehicle mass and all the interconnected circuits and
components supplied at a voltage of band I shall not be measured unless specifically required by the
operator.
The test is considered successful when the insulation resistance, measured and expressed in
Megaohms, is equal or exceeding 4 MΩ.
Depending on the provisions (according EN 50153) to prevent electrical hazards, if applicable, the
insulation test can be included in the periodical insulation test.
3.2.11 Insulation resistance values for the parts concerned with the accesses to the vehicle
The parts concerned with the accesses of the vehicle (see 2.1.2 and 2.1.3) shall be tested for
insulation resistance between the same and the vehicle mass.
The measurements shall be carried out with a megaohmmeter having a generator, being part of the
instrument, with a voltage of 1 000 V d.c.; the test is considered successful if the insulation resistance
of every part is equal to or larger than 6 MΩ in dry and clean conditions. In wet conditions the limit
measure shall be 0,5 MΩ when the entrance flooring is immersed in local drinking water, contact area
wiped with shoes so that there is no visible film of water at the test point.
3.3 Overhauled trolley-vehicles
3.3.1 Tests and verification of the electrical equipment
Upon new commissioning of the overhauled vehicle, the verifications required under 3.2.1 to 3.2.4
shall be repeated with reduced values of 85 % of U .
a
3.3.2 Measurements and value of the insulation resistance
The insulation tests described in 3.2.5, 3.2.7, 3.2.8, 3.2.10 and 3.2.11 shall be carried out with
reference to the portion of electric installation revised and the voltage band associated.
The tests are considered successful when the insulation resistance is at least 1/3 of the values
required for a new vehicle; this is applicable also to the access parts under 2.1.2 and 2.1.3.

3.3.3 Insulation test modalities
See the requirements in 3.2.6 and 3.2.9.
3.4 On-duty trolley vehicles (periodical checks)
...