SIST EN ISO 19659-4:2026

SLOVENSKI STANDARD
01-junij-2026
Železniške naprave - Ogrevalni, prezračevalni in klimatski sistemi za vozna
sredstva - 4. del: Konstrukcijski parametri, preskusni in kontrolni elementi za
enoto HVAC (ISO 19659-4:2026)
Railway applications - Heating, ventilation and air conditioning systems for rolling stock -
Part 4: Design parameters, test and inspection items for the HVAC unit (ISO 19659-
4:2026)
Bahnanwendungen - Heizung, Lüftung und Klimatisierung von Schienenfahrzeugen -
Teil 4: Grundlegende Konstruktionsparameter, Messungen und Prüfungen für die
HLK‑Einheit (ISO 19659-4:2026)
Applications ferroviaires - Systèmes de chauffage, ventilation et climatisation pour le
matériel roulan - Partie 4: Paramètres de conception, éléments d’essai et d’inspection
pour l’unité HVAC (ISO 19659-4:2026)
Ta slovenski standard je istoveten z: EN ISO 19659-4:2026
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.

EN ISO 19659-4
EUROPEAN STANDARD
NORME EUROPÉENNE
April 2026
EUROPÄISCHE NORM
ICS 45.060.01
English Version
Railway applications - Heating, ventilation and air
conditioning systems for rolling stock - Part 4: Design
parameters, and test and inspection items for the HVAC
unit (ISO 19659-4:2026)
Applications ferroviaires - Systèmes de chauffage, Bahnanwendungen - Heizung, Lüftung und
ventilation et climatisation pour le matériel roulant - Klimatisierung von Schienenfahrzeugen - Teil 4:
Partie 4: Paramètres de conception et éléments d'essai Grundlegende Auslegungsparameter, Messungen und
et d'inspection pour l'unité HVAC (ISO 19659-4:2026) Prüfungen für die HLK-Einheit (ISO 19659-4:2026)
This European Standard was approved by CEN on 27 January 2026.

CEN 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 CEN
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 CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2026 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 19659-4:2026 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 19659-4:2026) has been prepared by Technical Committee ISO/TC 269
"Railway applications" in collaboration with Technical Committee CEN/TC 256 “Railway applications”
the secretariat of which is held by DIN.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by October 2026, and conflicting national standards shall
be withdrawn at the latest by October 2026.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
Any feedback and questions on this document should be directed to the users’ national standards
body/national committee. A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the
United Kingdom.
Endorsement notice
The text of ISO 19659-4:2026 has been approved by CEN as EN ISO 19659-4:2026 without any
modification.
International
Standard
ISO 19659-4
First edition
Railway applications — Heating,
2026-04
ventilation and air conditioning
systems for rolling stock —
Part 4:
Design parameters, and test and
inspection items for the HVAC unit
Applications ferroviaires — Systèmes de chauffage, ventilation et
climatisation pour le matériel roulant —
Partie 4: Paramètres de conception et éléments d’essai et
d’inspection pour l’unité HVAC
Reference number
ISO 19659-4:2026(en) © ISO 2026

ISO 19659-4:2026(en)
© ISO 2026
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
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CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii
ISO 19659-4:2026(en)
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms, definitions and abbreviated terms . 2
3.1 Terms and definitions .2
3.2 Abbreviated terms .2
4 Prerequisites (design parameters) for the HVAC unit . 3
4.1 General .3
4.2 Design parameters to be provided to the HVAC unit manufacturer .3
4.2.1 HVAC unit installation requirements .3
4.2.2 Air flow requirements .3
4.2.3 Cooling and heating performance requirements .5
4.2.4 Electric and electronic requirements .7
4.2.5 Control requirements . .9
4.2.6 Structure requirements .11
4.2.7 Strength requirements .11
4.2.8 Component requirements. 12
4.2.9 Maintenance requirements . 12
4.2.10 Environmental requirements . 13
4.2.11 Noise and vibration requirements. 13
4.3 Summary of design parameters . 13
5 Specification .13
5.1 General . 13
5.2 Test or inspection items and requirement specifications by the HVAC unit manufacturer . 13
5.2.1 Air volume flow rate and system pressure drop test . 13
5.2.2 Cooling and heating tests .14
5.2.3 Functional test.14
5.2.4 Cooling and heating operation and safety checks .14
5.2.5 Noise test .14
5.2.6 Blocked forces (if applicable) . 15
5.2.7 Shock and vibration test . 15
5.2.8 Water tightness test . 15
5.2.9 Air tightness test (if applicable) . 15
5.2.10 Air leakage test (if applicable) .16
5.2.11 Electrical insulation resistance and dielectric test .16
5.2.12 Starting characteristics test .16
5.2.13 Refrigerant circuit tightness test .16
5.2.14 Mass and centre of gravity measurement .16
5.2.15 Visual, dimensional and constructional inspection.16
5.2.16 Maintainability demonstration .16
5.2.17 Marking and labelling inspection .16
5.2.18 EMC test . .17
5.2.19 Specific materials and parts tests.17
5.3 Classification of test and inspection items .17
6 Validation and verification .18
6.1 General .18
6.2 Recording and measuring instruments .19
6.2.1 General .19
6.2.2 Recording .19
6.2.3 Measuring instruments . .19
6.3 Test and inspection procedures including test facility and equipment, data to be
recorded, position of measuring points and criteria.19

iii
ISO 19659-4:2026(en)
6.3.1 Air volume flow rate and system pressure drop test .19
6.3.2 Cooling and heating tests . 22
6.3.3 Functional test. 28
6.3.4 Cooling and heating operation and safety checks . 30
6.3.5 Noise test .32
6.3.6 Blocked forces test . 36
6.3.7 Shock and vibration test . 38
6.3.8 Water tightness test . 40
6.3.9 Air tightness test .43
6.3.10 Air leakage test .45
6.3.11 Electrical insulation resistance and dielectric test .47
6.3.12 Starting characteristics test (if applicable) . 48
6.3.13 Refrigerant circuit tightness test . 50
6.3.14 Mass and centre of gravity measurement .52
6.3.15 Visual, dimensional and constructional inspection. 53
6.3.16 Maintainability demonstration . 55
6.3.17 Marking and labelling inspection . 55
6.3.18 EMC test . . 55
6.3.19 Specified materials and parts tests . 58
6.4 Test or inspection report . 60
6.4.1 General information . 60
6.4.2 Type test report . 60
6.4.3 Routine test report .61
Annex A (informative) List of the design parameters to be provided to the HVAC unit
manufacturer .62
Bibliography .68

iv
ISO 19659-4:2026(en)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO technical committees. Each member body interested in a subject for which a technical committee
has been established has the right to be represented on that committee. International organizations,
governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely
with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types
of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 269, Railway applications, Subcommittee SC 2,
Rolling stock, in collaboration with the European Committee for Standardization (CEN) Technical Committee
CEN/TC 256, Railway applications, in accordance with the Agreement on technical cooperation between ISO
and CEN (Vienna Agreement).
A list of all parts in the ISO 19659 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

v
ISO 19659-4:2026(en)
Introduction
Since the heating, ventilation and air conditioning (HVAC) unit is one of the main components of the HVAC
system, its quality and performance is a key issue to improve thermal comfort and energy efficiency for
rolling stock.
The purpose is:
— to develop a common International Standard for the validation of a HVAC unit,
— to establish methodologies and requirements on a component basis to demonstrate conformity with the
technical specifications of the HVAC unit,
— to establish a clear scope of responsibility in case performance issues occur after mounting the HVAC
unit on the rolling stock.
The justification is:
— currently, there is no common International Standard for the validation of a HVAC unit;
— generally, existing national and regional HVAC unit standards are designed for air-conditioning systems
in buildings; there only a few standards for rolling stock;
— therefore, there is a need to unify the methodologies of the HVAC unit standards into one single document;
— this will not affect any existing national or regional standard.

vi
International Standard ISO 19659-4:2026(en)
Railway applications — Heating, ventilation and air
conditioning systems for rolling stock —
Part 4:
Design parameters, and test and inspection items for the
HVAC unit
1 Scope
This document specifies requirements and guidelines for:
— the design parameters to be provided to the heating, ventilation and air conditioning (HVAC) unit
manufacturer by the rolling stock manufacturer (“Customer”) and the railway operator,
— the test and inspection items, requirements and methods used by the HVAC unit manufacturer to verify
that the HVAC unit conforms with the design parameters.
This document is applicable to HVAC units for the passenger area and driver’s cabs in urban (metro,
tramway), suburban, regional and main line vehicles.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements 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.
ISO 3743-1, Acoustics — Determination of sound power levels and sound energy levels of noise sources using
sound pressure — Engineering methods for small movable sources in reverberant fields — Part 1: Comparison
method for a hard-walled test room
ISO 3743-2, Acoustics — Determination of sound power levels of noise sources using sound pressure —
Engineering methods for small, movable sources in reverberant fields — Part 2: Methods for special reverberation
test rooms
ISO 3744, Acoustics — Determination of sound power levels and sound energy levels of noise sources using sound
pressure — Engineering methods for an essentially free field over a reflecting plane
ISO 3745, Acoustics — Determination of sound power levels and sound energy levels of noise sources using sound
pressure — Precision methods for anechoic rooms and hemi-anechoic rooms
ISO 3746, Acoustics — Determination of sound power levels and sound energy levels of noise sources using sound
pressure — Survey method using an enveloping measurement surface over a reflecting plane
ISO 3747, Acoustics — Determination of sound power levels and sound energy levels of noise sources using sound
pressure — Engineering/survey methods for use in situ in a reverberant environment
ISO 9614-2, Acoustics — Determination of sound power levels of noise sources using sound intensity — Part 2:
Measurement by scanning
ISO 19659-1, Railway applications — Heating, ventilation and air conditioning systems for rolling stock — Part
1: Terms and definitions
ISO 19659-4:2026(en)
ISO 19659-2, Railway applications — Heating, ventilation and air conditioning systems for rolling stock — Part
2: Thermal comfort
ISO 19659-3, Railway applications — Heating, ventilation and air conditioning systems for rolling stock — Part
3: Energy efficiency
IEC 60077-1, Railway applications — Electric equipment for rolling stock — Part 1: General service conditions
and general rules
IEC 60077-2, Railway applications — Electric equipment for rolling stock — Part 2: Electrotechnical components
— General rules
IEC 61373, Railway applications — Rolling stock equipment — Shock and vibration tests
IEC 62236-3-2, Railway applications — Electromagnetic compatibility — Part 3-2: Rolling stock — Apparatus
3 Terms, definitions and abbreviated terms
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 19659-1 apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.2 Abbreviated terms
For the purposes of this document, the abbreviated terms given in ISO 19659-1 and the following apply.
AC Alternating current
CMM Coordinate measuring machine
DB Dry bulb
DC Direct current
EMC Electromagnetic compatibility
FEM Finite element method
FFT Fast Fourier transform
FST Fire, smoke and toxicity
GWP Global warming potential
HF High frequency
HVAC Heating, ventilation and air conditioning
LED Light emitting diode
PTC Positive temperature coefficient
PTU Portable testing unit
RMS Root mean square
ISO 19659-4:2026(en)
RPM Revolutions per minute
TCMS Train control monitor system
VOC Volatile organic compounds
WB Wet bulb
4 Prerequisites (design parameters) for the HVAC unit
4.1 General
The design parameters shall be clearly specified in the technical specification so that the HVAC unit
manufacturer can design and build the HVAC unit to meet the customers' requirements.
This clause gives an overview of the design parameters that should be specified as good engineering practice
including the parameters to calculate the total annual energy consumption and the total annual energy
efficiency of the HVAC unit. The latter is important, as in most cases, after the traction system, the HVAC
system is the second largest power consumer on the train.
4.2 Design parameters to be provided to the HVAC unit manufacturer
4.2.1 HVAC unit installation requirements
As a minimum, the following design parameters shall be provided:
— the type of the railway vehicle (high speed, commuter, Cat. 1, Cat. 2, Cat. 3 in ISO 19659-2),
— the type of the HVAC unit (compact, split in ISO 19659-1),
— HVAC unit location (roof mounted, roof embedded, ceiling mounted, on floor mounted, under floor
mounted in ISO 19659-1),
— the number of the HVAC units per railway vehicle.
These design parameters are summarized in Table A.1.
4.2.2 Air flow requirements
4.2.2.1 Air volume flow rates
The following design parameters shall be considered for air flow requirements:
a) fresh air volume flow rate:
— fresh air volume flow rate per person depending on operating conditions as specified in relevant
national or regional standard or in its absence ISO 19659-2,
— number of passengers (normal and maximum);
NOTE In case the free cooling mode is required, the fresh air volume flow rate can be higher. The free cooling
mode is specified in ISO 19659-1.
b) supply air volume flow rate based on following heat gains:
— heat transfer (including glazing),
— heat emission from person specified in ISO 19659-2,
— fresh air (specified in ISO 19659-1) (ventilation),

ISO 19659-4:2026(en)
— passenger door cycling air infiltration,
— solar radiation (glazing and opaque surfaces) specified in ISO 19659-2,
— heat emission of supply fans and other equipment specified in ISO 19659-2,
— lighting and miscellaneous internal heat gains specified in ISO 19659-2;
c) return air volume flow rate;
d) exhaust air volume flow rate: air volume flow rate required to be exhausted from technical cabinets,
WCs, galleys, etc. and to compensate the fresh air volume rates to maintain the required vehicle inside
pressure;
e) infiltration air volume flow rate.
These design parameters are summarized in Table A.2.
4.2.2.2 Back pressure at air interfaces
The following design parameters shall be considered for back pressure at air interfaces:
a) fresh air inlet back pressure:
— pressure loss through the ducts,
— type and efficiency of air filters in 4.2.8,
— filter condition (clean or dirty),
— external contamination,
— drip or mist separator,
— dampers action,
— back pressure due to train speed, especially in case of a high-speed train,
— back pressure due to other equipment;
b) supply air outlet back pressure:
— pressure loss through the ducts,
— dampers action,
— mechanical parts friction,
— diffusers,
— vehicle internal pressure;
c) return air inlet back pressure:
— pressure loss through the ducts,
— type and efficiency of air filters in 4.2.8,
— filter condition (clean or dirty),
— internal contamination,
— dampers action,
— vehicle internal pressure;
ISO 19659-4:2026(en)
d) exhaust air back pressure, if applicable:
— pressure loss through the ducts,
— back pressure due to train speed, especially in case of a high-speed train,
— back pressure due to other equipment,
— dampers action,
— vehicle internal pressure.
These design parameters are summarized in Table A.2.
4.2.2.3 Air flow distribution
Air flow distribution (uniformity of air speed, temperature) at the supply air flow outlet(s), shall be
considered.
The design parameter is summarized in Table A.2.
4.2.3 Cooling and heating performance requirements
4.2.3.1 Common requirements
The design conditions shall be specified as described in ISO 19659-2:
a) exterior design conditions:
— temperature and corresponding relative humidity,
— solar radiation,
— altitude,
— train speed;
b) extreme exterior conditions;
c) fresh air volume flow rate;
d) interior design conditions;
— temperature and maximum corresponding relative humidity,
— latent and sensible loads.
The thermal impact of other systems on the train and of the infrastructure on the HVAC system shall be
specified and taken into account.
NOTE Other systems are, for example, braking resistors, battery cooling system and traction converter. An
example for the infrastructure would be recycling of expelled air due to tunnel or station platform.
The maximum total annual energy consumption and maximum power consumption of the HVAC unit should
be specified.
These design parameters are summarized in Table A.3.
Based on the above and the car data, the information for the design and testing of the HVAC unit shall be
derived.
ISO 19659-4:2026(en)
4.2.3.2 Cooling performance requirements
The design parameters in 4.2.3.1 and the following design parameters shall be provided:
a) exterior condition (air temperature and relative humidity): design point, maximum operating point,
minimum operating point;
b) mixed air condition or interior condition (air temperature and relative humidity): design point,
maximum operating point, minimum operating point;
c) cooling capacity (total cooling capacity and sensible cooling capacity) or supply air condition (in
combination with supply air volume flow rate from 4.2.2); if a different cooling capacity is required
for pre-cooling mode, degraded mode, free cooling mode or other conditions, cooling capacity and
conditions should be specified;
d) local air temperature (in case that they are different from exterior value)
— fresh air inlet,
— outdoor heat exchanger air inlet;
e) information if the system has reheating conditions to control inside maximum humidity level;
f) filter condition (clean or dirty), e.g. 20 % of surface covered, 10 % reduction in air volume flow rate,
simulation of maximum acceptable pressure drop at nominal air volume flow rate;
g) heat exchangers condition (clean or dirty), e.g. 20 % of surface covered, 10 % reduction in air volume
flow rate;
h) pressure drop caused by outside air flow speed or other factors affecting the total pressure drop of
outdoor heat exchanger area in the HVAC unit;
i) additional operating point to calculate the total annual energy consumption for the HVAC unit, if any
(refer to ISO 19659-3).
These design parameters are summarized in Table A.3.
4.2.3.3 Heating performance requirements (electric heater type)
The following design parameters in 4.2.3.1 and the following design parameters shall be provided:
a) exterior condition (air temperature): design point, maximum operating point;
b) mixed air condition or interior condition (air temperature): design point, maximum operating point;
c) heating capacity or supply air condition (in combination with supply air volume flow rate from 4.2.2);
if a different heating capacity is required for pre-heating mode, degraded mode or other conditions,
heating capacity and conditions should be specified;
NOTE Heating capacity can be provided by other equipment such as electric heater installed under passenger
seat. The heating capacity for design of HVAC unit is the capacity required for HVAC unit only.
d) local air temperature (in case that they are different from exterior value): fresh air inlet;
e) filter condition (clean or dirty);
f) maximum allowable duct temperature;
g) additional operating point to calculate the total annual energy consumption for the HVAC unit, if any
(refer to ISO 19659-3);
h) information about exhaust heat recovery system (system schematic, operation, etc.) to cooperate with
the HVAC unit, if it exists.
ISO 19659-4:2026(en)
These design parameters are summarized in Table A.3.
4.2.3.4 Heating performance requirements (heat pump type)
The following design parameters in 4.2.3.1 and the following design parameters shall be provided:
a) exterior condition (air temperature and relative humidity): design point, maximum operating point,
minimum operating point;
NOTE 1 Relative humidity is only relevant for outdoor heat exchanger.
b) mixed air condition or interior condition (air temperature): design point, maximum operating point,
minimum operating point;
c) heating capacity or supply air condition (in combination with supply air volume flow rate from 4.2.2);
NOTE 2 Heating capacity can be provided by other equipment such as electric heaters installed under
passenger seats. The heating capacity to be provided as design parameter of HVAC unit is the capacity required
for the HVAC unit only.
If a different heating capacity is required for pre-heating mode, degraded mode or other conditions,
heating capacity and conditions should be specified.
d) local air temperature (in case that they are different from exterior value):
— fresh air inlet,
— outdoor heat exchanger air inlet;
e) filter condition (clean or dirty);
f) maximum allowable duct temperature;
g) heat exchangers condition (clean or dirty);
h) pressure drop caused by outside air flow speed or other factors affecting the total pressure drop of
outdoor heat exchanger area in the HVAC unit;
i) additional operating point to calculate the total annual energy consumption for the HVAC unit, if any
(refer to ISO 19659-3);
j) information about exhaust heat recovery system (system schematic, operation, etc.) to cooperate with
the HVAC unit, if it exists.
These design parameters are summarized in Table A.3.
4.2.4 Electric and electronic requirements
4.2.4.1 General
Subclause 4.2.4 covers the use of on board electrical and electronic equipment inside the HVAC unit on
rolling stock.
Electronic and electrical equipment inside the HVAC unit shall be designed and manufactured to meet the
full performance specification requirement for the actual temperatures occurring at the location of the
equipment concerned. The design shall take into account temperature rises within cubicles to ensure that
the components do not exceed their specified temperature ratings.

ISO 19659-4:2026(en)
4.2.4.2 Electronic requirement
4.2.4.2.1 General
Electrical machinery produces electromagnetic interference and therefore, it is important to reduce this
as much as possible so that other sensitive electrical and electronic devices, for example, other on-train
electronic and electrical equipment or hand-held radio-transmitters, do not malfunction.
The EMC test to be applied (e.g. IEC 62236-3-2 or another equivalent standard) shall be specified.
These design parameters are summarized in Table A.4.
4.2.4.2.2 Immunity requirements
The electronic components within the HVAC unit shall have immunity from specified fast transients, surges,
electrostatic discharges and radio frequencies.
4.2.4.2.3 Emission requirements
The conducted and radiated disturbances generated by electronic components within the HVAC unit shall
respect the specified emission limits.
4.2.4.3 Power supply
4.2.4.3.1 Supply from accumulator battery
For equipment supplied from a battery, the following design parameters shall be provided:
— nominal and rated voltage,
— minimum and maximum voltage during a specific time interval,
— DC ripple factor,
— interruptions of voltage to be taken into account (frequency and duration),
— allowable power consumption for the HVAC unit (normal, reduced power supply) under different
conditions (e.g. design conditions, extreme conditions and emergency ventilation),
— allowable power consumption for the HVAC unit in operational points of operational point matrix for
calculation total annual energy consumption.
These design parameters are summarized in Table A.4.
4.2.4.3.2 Supply by a static converter or an independently driven generator
For equipment supplied from a static converter or a rotating set, the following design parameters shall be
provided:
— nominal and rated voltage,
— minimum and maximum voltage during a specific time interval,
— number of phases and availability of neutral line,
— fundamental frequency and tolerance,
— harmonics,
— maximum allowed imbalance,
— minimum allowed power factor,

ISO 19659-4:2026(en)
— interruptions of voltage to be taken into account (frequency and duration),
— maximum inrush current,
— allowable real and apparent power consumption for the HVAC unit (normal, reduced power supply)
under different conditions (e.g. design conditions, extreme conditions and emergency ventilation) in kW
and kVA,
— allowable power consumption for the HVAC unit in operational points of operational point matrix for
calculation total annual energy consumption.
These design parameters are summarized in Table A.4.
4.2.4.3.3 Supply with overhead line or third rail
For equipment for which the power supply is derived directly from the overhead line or third rail, power
supply shall be in accordance with IEC 60850 or another equivalent standard.
The following design parameters shall be provided:
— nominal and rated voltage,
— minimum and maximum voltage during a specific time interval,
— interruptions of voltage to be taken into account (frequency and duration),
— allowable power consumption for the HVAC unit (normal, reduced power supply) under different
conditions (e.g. design conditions, extreme conditions),
— allowable power consumption for the HVAC unit in operational points of operational point matrix for
calculation total annual energy consumption.
These design parameters are summarized in Table A.4.
4.2.4.4 Other design parameters
Additionally, the following design parameters shall be provided:
— dielectric test voltages
...