FprEN 50155:2025

SLOVENSKI STANDARD
oSIST prEN 50155:2024
01-november-2024
Železniške naprave - Vozna sredstva - Elektronska oprema
Railway applications - Rolling stock - Electronic equipment
Bahnanwendungen - Elektronische Einrichtungen auf Schienenfahrzeugen
Applications ferroviaires - Équipements électroniques utilisés sur le matériel roulant
Ta slovenski standard je istoveten z: prEN 50155:2024
ICS:
45.060.01 Železniška vozila na splošno Railway rolling stock in
general
oSIST prEN 50155:2024 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

oSIST prEN 50155:2024
oSIST prEN 50155:2024
EUROPEAN STANDARD DRAFT
prEN 50155
NORME EUROPÉENNE
EUROPÄISCHE NORM
September 2024
ICS 45.060.01 Will supersede EN 50155:2021
English Version
Railway applications - Rolling stock - Electronic equipment
Applications ferroviaires - Équipements électroniques Bahnanwendungen - Elektronische Einrichtungen auf
utilisés sur le matériel roulant Schienenfahrzeugen
This draft European Standard is submitted to CENELEC members for enquiry.
Deadline for CENELEC: 2024-11-29.

It has been drawn up by CLC/SC 9XB.

If this draft becomes a European Standard, 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.

This draft European Standard was established by CENELEC 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, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the
Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Türkiye and the United Kingdom.

Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are aware and to
provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without notice and
shall not be referred to as a European Standard.

European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2024 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Project: 76619 Ref. No. prEN 50155:2024 E

oSIST prEN 50155:2024
prEN 50155:2024 (E)
Contents Page
1 European foreword . 7
Introduction . 12
3 1 Scope . 13
4 2 Normative references . 13
5 Terms, definitions and abbreviations . 15
6 3.1 Terms and definitions . 15
7 3.2 Abbreviations . 21
8 General requirements . 22
9 4.1 Requirement for equipment characteristics. 22
10 4.2 Classes of environmental, constructional and service conditions . 22
11 Performance criteria . 22
4.3
12 4.3.1 General . 22
13 4.3.2 Performance criterion A . 23
14 Performance criterion B . 23
4.3.3
15 4.3.4 Performance criterion C . 23
16 4.4 Environmental service conditions . 23
17 Altitude . 23
4.4.1
18 4.4.2 Operating temperature . 23
19 4.4.3 Increased operating temperature at switch-on . 25
20 Rapid temperature variations . 25
4.4.4
21 4.4.5 Shock and vibration. 26
22 4.4.6 Electromagnetic compatibility . 26
23 Relative humidity . 26
4.4.7
24 4.5 Special service conditions . 27
25 4.5.1 General . 27
26 Atmospheric pollutants . 27
4.5.2
27 4.6 Installation requirements . 27
28 4.6.1 General . 27
29 Installation instructions . 27
4.6.2
30 4.6.3 Battery voltage supply system . 27
31 4.6.4 Thermal compatibility . 27
32 Electromagnetic compatibility . 27
4.6.5
33 4.6.6 Cabling inside vehicle . 28
34 4.6.7 Wiring inside equipment . 28
35 Insulation of the installation . 28
4.6.8
36 5 Electrical service conditions . 28
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37 5.1 Typical supply systems .28
38 5.1.1 General .28
39 5.1.2 DC supply system .28
40 AC supply system .29
5.1.3
41 5.2 Battery voltage supply system .30
42 5.2.1 General .30
43 Supply voltage range .30
5.2.2
44 5.2.3 Temporary supply voltage variation .31
45 5.2.4 Interruption of supply voltage .31
46 Supply change-over .32
5.2.5
47 5.2.6 Grouping of supply voltages .32
48 5.2.7 DC ripple factor .32
49 Behaviour of system power supply during start of combustion engine .33
5.2.8
50 5.3 Supply by another source than the vehicle battery .33
51 5.3.1 Supply by a specific DC or AC source .33
52 Supply by an AC auxiliary power converter .33
5.3.2
53 5.3.3 Supply with overhead line or third rail .34
54 5.3.4 Design and test requirements for AC supply .34
55 Reliability, maintainability and expected useful life .34
56 6.1 Equipment reliability .34
57 6.1.1 Predicted reliability .34
58 Proof of reliability .34
6.1.2
59 6.2 Useful life .34
60 6.3 Maintainability .35
61 General .35
6.3.1
62 6.3.2 Preventive maintenance .35
63 6.3.3 Corrective maintenance .35
64 Built-in diagnostics .36
6.3.4
65 6.4 Automatic test equipment .36
66 6.5 Purpose-built test equipment and special tools .36
67 Design .36
68 7.1 General .36
69 7.1.1 Quality management .36
70 System life cycle model .37
7.1.2
71 7.2 Detailed practices - Hardware .37
72 7.2.1 Insulation coordination .37
73 Interfacing .37
7.2.2
74 7.2.3 Fault protection .38
75 7.2.4 Reference potential of power supplies .38
76 Interchangeability .39
7.2.5
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77 7.2.6 Reduction of supply voltage and ON/OFF phases . 39
78 7.2.7 Reverse polarity protection . 39
79 7.2.8 Inrush currents . 39
80 Energetic transient pulses . 39
7.2.9
81 7.2.10 Capacitance to earth . 39
82 7.2.11 Spare capacity . 39
83 User Programmable Integrated Circuit . 39
7.2.12
84 7.3 Detailed practices - Software . 40
85 7.3.1 General . 40
86 Life cycle . 40
7.3.2
87 7.4 Features of software-controlled equipment . 40
88 7.4.1 General . 40
89 Self-test . 40
7.4.2
90 7.4.3 Watchdog . 40
91 7.4.4 Failure indication . 40
92 Recover from fault or error state . 40
7.4.5
93 8 Electronic equipment not designed for use on rolling stock . 40
94 9 Components . 41
95 Procurement . 41
9.1
96 9.2 Application . 41
97 10 Construction . 41
98 Equipment construction . 41
10.1
99 10.1.1 General . 41
100 10.1.2 Mechanical protection . 42
101 Polarization or coding. 42
10.1.3
102 10.1.4 Dimensional requirements . 42
103 10.2 Component mounting . 42
104 General . 42
10.2.1
105 10.2.2 Layout . 42
106 10.2.3 Fixing . 43
107 Component lead terminations . 43
10.2.4
108 10.2.5 Integrated circuit sockets and edge connectors . 43
109 10.2.6 Pre-set control . 43
110 Select-on-test components . 43
10.2.7
111 10.3 Electrical connections . 43
112 10.3.1 General . 43
113 Solder connections. 43
10.3.2
114 10.3.3 Crimped connections . 44
115 10.3.4 Wire wrap connections . 44
116 Other connections . 44
10.3.5
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117 10.4 Internal flexible wiring (electrical and optical) .44
118 10.5 Flexible printed wiring .44
119 10.6 Printed circuit boards - flexible and rigid .45
120 General .45
10.6.1
121 10.6.2 Holes .45
122 10.6.3 Printed circuit board acceptability .45
123 Layout .45
10.6.4
124 10.6.5 Materials .45
125 10.7 Protective coatings for printed board assemblies .45
126 Identification .46
10.8
127 10.8.1 Bare PCB identification .46
128 10.8.2 Identification of subracks and printed board assemblies .46
129 Mounting position of subracks and printed board assemblies .46
10.8.3
130 10.8.4 Fuse and battery identification .46
131 10.9 Mounting .46
132 Cooling and ventilation .46
10.10
133 10.11 Materials and finishes .46
134 10.12 Reworking, modification and repair of electronic assemblies .47
135 Safety .47
136 11.1 General .47
137 11.2 Personnel safety .47
138 General .47
11.2.1
139 11.2.2 Personnel safety against electric shock .47
140 11.2.3 Personnel safety against effects of excessive temperature .47
141 Functional safety .47
11.3
142 11.4 Fire behaviour requirements .47
143 12 Documentation .48
144 General .48
12.1
145 12.2 Supply and storage of documentation .48
146 12.3 Datasheet .48
147 User and maintenance manual .48
12.4
148 12.5 Installation documentation .48
149 12.6 Commissioning documentation .49
150 Design documentation .49
12.7
151 12.7.1 Documentation – Hardware .49
152 12.7.2 User Programmable Integrated Circuits (UPIC, e.g. FPGA, PLD, ASIC) .51
153 Documentation – Software .52
12.7.3
154 12.8 Manufacturing data .52
155 12.9 Repair documentation .52
156 General .52
12.9.1
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157 12.9.2 Special tools . 52
158 12.9.3 Non-repairable items list . 52
159 12.10 Documentation – System . 52
160 Testing . 53
161 13.1 General . 53
162 13.2 Categories of tests . 53
163 General . 53
13.2.1
164 13.2.2 Type tests . 54
165 13.2.3 Routine tests . 54
166 Investigation tests . 54
13.2.4
167 13.3 List of tests and test conditions . 55
168 13.3.1 List of tests . 55
169 Conditions during testing . 55
13.3.2
170 13.4 Description of the tests . 55
171 13.4.1 Visual inspection . 55
172 Performance test . 56
13.4.2
173 13.4.3 DC Power supply test. 56
174 13.4.4 Low temperature test . 60
175 Dry heat test . 61
13.4.5
176 13.4.6 Low temperature storage test . 65
177 13.4.7 Insulation test . 65
178 Cyclic damp heat test . 67
13.4.8
179 13.4.9 Electromagnetic compatibility test . 69
180 13.4.10 Shock and vibration test . 69
181 Stress screening test. 70
13.4.11
182 13.4.12 Rapid temperature variation test . 70
183 13.4.13 Salt mist test . 71
Annex A (informative) List of default requirements of EN 50155 and related subclauses . 72
185 Annex B (informative) System testing approach . 73
186 Annex C (informative) Severity level of service conditions in different vehicle locations . 77
Annex D (informative) Example of an equipment tests compliance summary sheet. 81
188 Annex E (informative) User programmable integrated circuit life cycle example . 83
189 Annex F (informative) Design suggestions for electronic hardware used on rolling stock . 84
Annex G (informative) Electronic equipment not designed for use on rolling stock . 94
191 Annex H (informative) Paragraphs with Agreements between the involved Parties . 96
192 Annex I (informative) Electronic equipment supplied from AC supply system . 100
Annex J (informative) Typical content of datasheets . 101
194 Annex K (informative) Insulation test and testing matrix example . 105
195 Annex ZZ (informative) Relationship between this European Standard and the Essential
196 Requirements of EU Directive (EU) 2016/797 aimed to be covered. 107
197 Bibliography . 110
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198 European foreword
199 This document (prEN 50155:2024) has been prepared by CLC/SC 9XB, “Electrical, electronic and
200 electromechanical material on-board rolling stock, including associated software”.
201 The following dates are proposed:
• latest date by which the existence of this (doa) dor + 6 months
document has to be announced at national
level
• latest date by which this document has to be (dop) dor + 12 months
implemented at national level by publication of
an identical national standard or by
endorsement
• latest date by which the national standards (dow) dor + 36 months
conflicting with this document have to be (to be confirmed or
withdrawn modified when voting)
202 This document will supersede EN 50155:2021 and all of its amendments and corrigenda (if any).
203 prEN 50155:2024 includes the following significant technical changes with respect to EN 50155:2021:
204 a) Revision of Clause 1 Scope;
205 1) Scope regarding “Software requirements for on-board railway equipment” is covered by EN 50716.
206 b) Updating of Clause 2 Normative references;
207 c) Revision of Clause 3 Terms, definitions and abbreviations”, new definitions and reorganization of
208 subclauses;
209 1) Definition modified for “operating temperature”;
210 2) Definition added for “ancillary component”;
211 d) Improvement of Clause 4 General requirements, in terms of better wording, requirement expansion and
212 reorganization of subclauses;
213 1) Precision about concept of expected performance level for all operational conditions.
214 2) Wording improvements of 4.3.2 to 4.3.3 “Performance criterion A and B;
215 3) Wording improvements of 4.4.2 about “Operating temperature classes” and concept of temperature
216 (45 °C) to consider during service life with its effects on unit material ageing.
217 e) Improvement of Clause 5 Electrical service conditions, with reorganization of subclauses;
218 1) Subclause “5.1.1 General” is added before “5.1.2 DC supply system” and “5.1.3 AC supply system”;
219 2) Nominal voltage (Un) of the electronic equipment “should” be selected amongst the following values:
220 24 V, 28 V, 36 V, 48 V, 72 V, 96 V, 110 V;
221 3) Wording improvement of 5.2.2 “Equipment shall operate satisfactorily within the voltage range and
222 duration defined in Table 4, measured at its power input terminals”;
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223 4) Wording improvement of 5.2.3 “Electronic equipment shall also operate at the values of the DC supply
224 voltage, which are measured at the terminals of the equipment, within the entire range of temporary
225 supply voltage variation defined in Table 4.”;
226 5) Wording improvement of 5.2.6 “EXAMPLE 3  Considering the maximum and minimum temporary
227 supply voltage for equipment designed to operate at nominal voltages from 24 V up to 110 V, the
228 minimum temporary voltage is 0,6 × 24 V and the maximum temporary voltage is 1,4 × 110 V”;
229 6) Wording improvement of 5.2.8 “Starting the combustion engine by a starter motor powered by the
230 battery voltage supply system can cause voltage drops and fluctuations on the battery voltage supply
231 system”;
232 7) 5.3.1 “Supply by a specific source” is renamed 5.3.1 “Supply by a specific DC or AC source”;
233 8) 5.3.2 “Supply by an AC auxiliary power converter”, sentence “In some special cases more restrictive
234 requirements for the voltage characteristics can be specified between the involved parties.” Is added;
235 9) 5.3.4 “Design and test requirements for AC supply” is added; with reference to informative Annex I;
236 f) Improvement of Clause 6 Reliability, maintainability and expected useful life;
237 1) 6.3.3.1, sentence “Maintenance or diagnostic procedures at this level shall not require the removal or
238 replacement of any part of the defective LRU” is added;
239 2) 6.5, sentence “The supplier shall provide information about purpose-built test equipment and/or special
240 tools are required to carry out the user's maintenance procedures.”, is added;
241 3) 6.5, sentence “Purpose-built test equipment does not necessarily have to comply with this standard”
242 is changed by “Purpose-built test equipment does not necessarily need to be in accordance with the
243 requirements of this document.”
244 g) Wording improvements and precision added to Clause 7 Design;
245 1) 7.2.4: Rewording of the sentence about reference potential of galvanically isolated power supplies
246 outputs.;
247 2) 7.2.6: The following sentence is added: “The equipment shall restart in normal operating mode when
248 the supply voltage is within the continuous voltage”
249 h) Clause 9 Components,
250 1) 9.1: The acronyms UPIC is used to identify the “user programmable integrated circuits”;
251 2) 9.2: Improvement of the text related to requirements that can be required at tender stage by the user
252 about reliability, the life duration of components and the documentation of the electronic equipment.;
253 i) Wording improvements and precisions added for Clause 10 Construction
254 1) 10.2.5: Added recommendation: “It is recommended to avoid integrated circuit socket and/or edge
255 connectors as far as possible”;
256 2) 10.6.5: Applicable standard about defined flammability of rigid PCB: “The base material of the rigid
257 PCB shall be epoxy and woven glass fabric laminated sheet of defined flammability in accordance with
258 EN 45545-2:2020+A1:2023.”;
259 3) 10.8.2: Precision about identification of subracks and PBA: “Means shall be provided on the subracks
260 and PBAs to indicate any revision/change in design or manufacturing.”;
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261 4) 10.11: Precision about “Materials and finishes”: “Potting to provide additional protection should only
262 be used if it is necessary for technical reasons” and “Coating and potting materials may not need to be
263 dimensionally stable as long as their thermal coefficient is considered to avoid high stress on
264 components or assemblies”.
265 j) Revision of Clause 12 Documentation;
266 1) 12.1: Added requirement about identification of “documents or drawings submitted to the user”: “shall
267 be identified by an appropriate and unambiguous reference, a date, a version or revision index, a
268 record of changes and an explanatory title of the presented item and of the type of document or
269 drawing.”;
270 2) 12.3: Precision about the datasheet content: “This document shall contain all information which the
271 user needs to evaluate whether the electronic equipment fulfils the requirements covered by the scope
272 of this document.”
273 3) 12.7: The design documentation structure is reorganised on the main topics: Hardware, User
274 Programmable Integrated Circuits (UPIC) and Software.
275 4) Subclauses that were previously in the topic “Repair documentation”: (e.g.: “12.7.10.2 Circuit
276 diagrams”, “12.7.10.3 Component list (Bill of material)” and 12.7.10.4 Component layout”) are moved
277 to the “Hardware” main documentation topic.;
278 5) 12.7.3: The new standard reference about “Requirements for software development” is used: “All
279 identified information items (documentation) shall be in accordance with EN 50716:2023.”
280 EN 50716 specifies the documentation required for the software development process but does not specify
281 the documentation to provide to the user. In the EN 50155 scope, the following requirement is kept:“the
282 supplier shall determine and list which information items are deliverable documents, consultable documents
283 and non-deliverable documents and which information items are to be archived.”, but the following sentence
284 is deleted: “At least the highly recommended documents (HR) in EN 50657:2017, Table A.1 column basic
285 integrity shall be provided for non-safety related on-board equipment.”
286 6) 12.9.1: Precisions about Repair documentation – General: “The equipment detailed repair
287 documentation is delivered only under specific request of the user and is subject to a contractual
288 agreement between supplier and user regarding the contents, the confidentiality and the rights of use
289 of this documentation.”
290 “NOTE  The list, the description, reference of special tools and the list of declared non-repairable
291 items, are not subjected to contractual agreement, confidentiality and right of use. (See: 12.9.2 and
292 12.9.3)”;
293 k) Improvements of Clause 13 Testing;
294 1) 13.1 General: Added precisions about the test specification: “A test specification defines the test
295 procedures and the acceptance criteria of the individual tests and the test sequence, if relevant. The
296 test specification shall be written by the supplier”.
297 “NOTE  Additional information are provided by Annex B for the verification of equipment by the system
298 integrator at system level.”
299 2) 13.2.2: Added precision about type tests and “production serial tests”: “Equipment used for type tests
300 shall previously been subjected to routine test. If the production routine tests are not ready at this step,
301 they may be replaced by equivalent tests.”
302 3) 13.4 title: “Test specification” is renamed “Description of the tests”;
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303 4) 13.4.2: Added precision about the performance test: “The performance test is carried out according to
304 the test specification, which contains the performance test procedure, written by the supplier either for
305 type test or for routine test.”
306 5) Test descriptions for 13.4.5.1, 13.4.5.2, 13.4.5.2 and 13.4.6 are improved.
307 6) 13.4.7.1: The following sentence is added for insulation test: “During the test all input / output of the
308 same equipotential area should be connected together in order to avoid damages due to unwanted
309 voltages within the equipotential area.”
310 7) 13.4.7.2: Additional details are provided for Insulation resistance test acceptance requirements when
311 high impedance bleeder resistors are inserted between adjacent equipotential areas or between an
312 equipotential area and functional earth.;
313 8) 13.4.8: Cyclic damp heat test: Additional details are provided for final test acceptance requirements:
314 l) Improvement of informative Annex A - List of default requirements of EN 50155 and related subclauses;
315 Content is updated;
316 m) Improvement of informative Annex B - System testing approach (In particular B.10)
317 n) Improvement of informative Annex C - Severity level of service conditions in different vehicle locations.
318 (Figure C.2)
319 o) Improvement of informative Annex D - Example for an equipment tests compliance summary sheet.
320 p) Informative Annex E User programmable integrated circuit life cycle example.
321 q) Improvement of informative Annex F – Design suggestions for electronic hardware used on rolling stock
322 1) F.1: Added precision: “The values given in Tables F.2 to F.19 are examples of typical use and can vary
323 from one design to another.”
324 2) F.2.2 Added precision: “Between battery referenced ports and earth, the use of voltage suppressors is
325 not recommended to ensure high dielectric isolation between battery referenced ports and earth.”
326 3) F.2.6 Prototype testing:
327 “At prototype stage, all functions should be verified according to the specification. It is also recommended
328 that the integrity of signals between parts of the circuit be investigated. Furthermore, it is strongly
329 recommended to carry out the tests following the type test specification.”
330 “These tests are intended as investigation tests, but they cannot be used to produce a type test report. One
331 of the reasons is that, normally, the prototype equipment is not manufactured according to the same
332 manufacturing process as a series equipment.”
333 4) F.2.7 Interfacing: About analogue and digital interfaces:
334 “They should be designed as differential inputs and/or outputs to ensure adequate common-mode noise
335 rejection.”
336 r) Improvement of informative Annex G - Electronic equipment not designed for use on rolling stock;
337 1) New text about “Applicability conditions for use of electronic equipment not designed for rolling stock”;
338 2) New text about “electronic equipment properties list” that should be comparable to the requirements in
339 this document.
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340 3) New text about “Possible deviations or mitigations for the suitability evaluation”;
341 s) Improvement of informative Annex H – Paragraphs with agreements between the involved parties.
342 1) Added Note:
343 “NOTE  Agreements between the involved parties (e.g. user and supplier) are not applicable to electronic
344 equipment that can be purchased as catalogue parts with qualification according to EN 50155. Since these
345 have been developed as generic products for a market, but not for a specific user”
346 t) Improvement of informative Annex I – Electronic equipment supplied from AC supply system;
347 1) Paragraph “I.1 General” is moved to 5.3.4.
348 2) New paragraph I.1 is renamed “Design and test provisions”
349 3) Table I.1 is completed by a new note:
350 If AC voltage is derived from an “AC Auxiliary Power converter” refer to EN 50533 for static voltage
351 tolerances and for short dips/interruptions.
352 If AC voltage is derived from any other AC source the technical specification of this local source, regarding
353 tolerances and short dips/interruptions, should be met. In the absence of information EN 50160 for static
354 voltage tolerances and EN IEC 61000-6-2 for short dips/interru
...