IEC 61820-3-4:2023

Electrical installations for lighting and beaconing of aerodromes - Part 3-4: Safety secondary circuits in series circuits - General safety requirements

IEC 61820-3-4:2023 specifies protective provisions for the operation of lamp systems powered by series circuits in aeronautical ground lighting.
The protective provisions described here refer only to secondary supply systems for loads that are electrically separated from the series circuit.
This document specifies the level of SELV, and alternatively PELV, under consideration of additional personnel protection during work on live secondary circuits by electrically skilled persons. This document also covers the special operational features of aeronautical ground lighting and addresses the level of training and the requirements for maintenance procedures detailed in IEC 61821 and other national or regional regulation.
The requirements and tests are intended to set a specification framework for system designers, system installers, users, and maintenance personnel to ensure a safe and economic use of electrical systems in installations for the beaconing of aerodromes.
This document complements existing IEC aeronautical ground lighting (AGL) standards and can be used as a design specification.

Installations électriques pour l'éclairage et le balisage des aérodromes - Partie 3-4: Circuits secondaires de sécurité dans les circuits série - Exigences générales de sécurité

L'IEC 61820-3-4:2023 spécifie des dispositions de protection pour le fonctionnement de systèmes d'éclairage alimentés par des circuits série pour le balisage aéronautique au sol.
Les dispositions de protection décrites ici se rapportent uniquement à des systèmes d'alimentation secondaires pour des charges séparées électriquement du circuit série.
Le présent document spécifie le niveau de TBTS et, en variante, de TBTP envisagé pour une protection supplémentaire du personnel lors d'un travail effectué sur des circuits secondaires sous tension par des personnes qualifiées en électricité. Le présent document couvre également les caractéristiques opérationnelles spéciales du balisage aéronautique au sol et traite du niveau de formation et des exigences relatives aux procédures de maintenance décrites dans l'IEC 61821 et dans d'autres réglementations nationales ou régionales.
Les exigences et les essais sont destinés à définir un cadre de spécification pour les concepteurs de systèmes, les installateurs de systèmes, les utilisateurs et le personnel de maintenance afin d'assurer une utilisation économique et en toute sécurité des systèmes électriques dans les installations destinées au balisage des aérodromes.
Le présent document complète les normes existantes de l'IEC relatives au balisage aéronautique au sol (AGL, Aeronautical Ground Lighting) et peut être utilisé comme spécification de conception.

General Information

• Status: Published
• Publication Date: 10-May-2023
• ICS: 29.140.50 - Lighting installation systems
• ICS: 93.120 - Construction of airports
• Technical Committee: TC 97 - Electrical installations for lighting and beaconing of aerodromes
• Drafting Committee: MT 3 - TC 97/MT 3
• Current Stage: PPUB - Publication issued
• Start Date: 16-Jun-2023
• Completion Date: 11-May-2023

Relations

• Replaces: IEC 62870:2015 - Electrical installations for lighting and beaconing of aerodromes - Safety secondary circuits in series circuits - General safety requirements
• Effective Date: 05-Sep-2023

Standards Content (Sample)

IEC 61820-3-4
®

Edition 1.0 2023-05
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside


Electrical installations for lighting and beaconing of aerodromes –
Part 3-4: Safety secondary circuits in series circuits – General safety
requirements

Installations électriques pour l'éclairage et le balisage des aérodromes –
Partie 3-4: Circuits secondaires de sécurité dans les circuits série – Exigences
générales de sécurité

IEC 61820-3-4:2023-05(en-fr)

---------------------- Page: 1 ----------------------
THIS PUBLICATION IS COPYRIGHT PROTECTED
Copyright © 2023 IEC, Geneva, Switzerland

All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from
either IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC
copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or
your local IEC member National Committee for further information.


Droits de reproduction réservés. Sauf indication contraire, aucune partie de cette publication ne peut être reproduite ni
utilisée sous quelque forme que ce soit et par aucun procédé, électronique ou mécanique, y compris la photocopie et
les microfilms, sans l'accord écrit de l'IEC ou du Comité national de l'IEC du pays du demandeur. Si vous avez des
questions sur le copyright de l'IEC ou si vous désirez obtenir des droits supplémentaires sur cette publication, utilisez
les coordonnées ci-après ou contactez le Comité national de l'IEC de votre pays de résidence.

IEC Secretariat Tel.: [phone]
3, rue de Varembé [e-mail]
CH-1211 Geneva 20 www.iec.ch
Switzerland

About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.

About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigendum or an amendment might have been published.

IEC publications search - webstore.iec.ch/advsearchform IEC Products & Services Portal - products.iec.ch
The advanced search enables to find IEC publications by a Discover our powerful search engine and read freely all the
variety of criteria (reference number, text, technical publications previews. With a subscription you will always have
committee, …). It also gives information on projects, replaced access to up to date content tailored to your needs.
and withdrawn publications.

Electropedia - www.electropedia.org
IEC Just Published - webstore.iec.ch/justpublished
The world's leading online dictionary on electrotechnology,
Stay up to date on all new IEC publications. Just Published
containing more than 22 300 terminological entries in English
details all new publications released. Available online and once
and French, with equivalent terms in 19 additional languages.
a month by email.
Also known as the International Electrotechnical Vocabulary

(IEV) online.
IEC Customer Service Centre - webstore.iec.ch/csc
If you wish to give us your feedback on this publication or need
further assistance, please contact the Customer Service
Centre: [e-mail].


A propos de l'IEC
La Commission Electrotechnique Internationale (IEC) est la première organisation mondiale qui élabore et publie des
Normes internationales pour tout ce qui a trait à l'électricité, à l'électronique et aux technologies apparentées.

A propos des publications IEC
Le contenu technique des publications IEC est constamment revu. Veuillez vous assurer que vous possédez l’édition la
plus récente, un corrigendum ou amendement peut avoir été publié.

Recherche de publications IEC - Découvrez notre puissant moteur de recherche et consultez
webstore.iec.ch/advsearchform gratuitement tous les aperçus des publications. Avec un
La recherche avancée permet de trouver des publications IEC abonnement, vous aurez toujours accès à un contenu à jour
en utilisant différents critères (numéro de référence, texte, adapté à vos besoins.
comité d’études, …). Elle donne aussi des informations sur les
projets et les publications remplacées ou retirées. Electropedia - www.electropedia.org

Le premier dictionnaire d'électrotechnologie en ligne au monde,
IEC Just Published - webstore.iec.ch/justpublished
avec plus de 22 300 articles terminologiques en anglais et en
Restez informé sur les nouvelles publications IEC. Just
français, ainsi que les termes équivalents dans 19 langues
Published détaille les nouvelles publications parues.
additionnelles. Egalement appelé Vocabulaire
Disponible en ligne et une fois par mois par email.
Electrotechnique International (IEV) en ligne.


Service Clients - webstore.iec.ch/csc
Si vous désirez nous donner des commentaires sur cette
publication ou si vous avez des questions contactez-nous:
[e-mail].
IEC Products & Services Portal - products.iec.ch

---------------------- Page: 2 ----------------------
IEC 61820-3-4

®


Edition 1.0 2023-05




INTERNATIONAL



STANDARD




NORME


INTERNATIONALE
colour

inside










Electrical installations for lighting and beaconing of aerodromes –

Part 3-4: Safety secondary circuits in series circuits – General safety

requirements



Installations électriques pour l'éclairage et le balisage des aérodromes –

Partie 3-4: Circuits secondaires de sécurité dans les circuits série – Exigences


générales de sécurité













INTERNATIONAL

ELECTROTECHNICAL

COMMISSION


COMMISSION

ELECTROTECHNIQUE


INTERNATIONALE




ICS 29.140.50; 93.120 ISBN 978-2-8322-7017-2




Warning! Make sure that you obtained this publication from an authorized distributor.

Attention! Veuillez vous assurer que vous avez obtenu cette publication via un distributeur agréé.

® Registered trademark of the International Electrotechnical Commission
Marque déposée de la Commission Electrotechnique Internationale

---------------------- Page: 3 ----------------------
– 2 – IEC 61820-3-4:2023 © IEC 2023
CONTENTS
FOREWORD . 5
INTRODUCTION . 7
1 Scope . 8
2 Normative references . 8
3 Terms, definitions, and abbreviated terms . 9
3.1 Terms and definitions . 9
3.2 Abbreviated terms . 12
4 Requirements for the SELV/PELV supply . 12
4.1 General . 12
4.2 SELV/PELV-safety demarcation line in an AGL series circuit . 12
4.3 Environmental conditions . 14
4.4 Degree of protection provided by enclosures . 14
4.5 Electromagnetic compatibility (EMC) . 14
4.5.1 Limits of electromagnetic emission . 14
4.5.2 Limits of immunity . 14
4.6 Marking . 14
4.6.1 Marking of the SELV/PELV power supply (single unit: safety transformer
combined with a limiter) . 14
4.6.2 Marking of the SELV/PELV power supply (multiple units: safety
transformer in series with a separate limiter) . 15
4.6.3 Marking at the installation locations . 15
4.7 Protection against electric shock . 15
4.7.1 Basic requirements . 15
4.7.2 Protective measure to be applied . 15
4.7.3 Voltage limit for the SELV/PELV circuit . 15
4.7.4 Protective separation from the primary series circuit . 17
4.7.5 Assemblies in the SELV/PELV supply . 18
4.8 Interfaces . 18
4.8.1 Supply unit . 18
4.8.2 Connectors . 18
5 Useful methodic for a SELV/PELV series circuit configuration . 18
5.1 General . 18
5.2 Method: systemic approach . 19
5.3 Method: extended systemic approach (with limiter) . 19
5.4 Verification of the chosen method . 19
6 Testing . 19
6.1 General . 19
6.2 System design test. 20
6.2.1 General . 20
6.2.2 Test for the "systemic approach" method . 20
6.2.3 Test for "extended systemic approach" method (device type test) . 21
6.3 Production routine tests . 23
6.3.1 Transformer test . 23
6.3.2 Limiter test . 23
6.4 Field test . 23
6.4.1 Field test without additional limiter . 23
6.4.2 Field test with additional limiter . 24

---------------------- Page: 4 ----------------------
IEC 61820-3-4:2023 © IEC 2023 – 3 –
Annex A (informative) System design selection . 26
Annex B (informative) Marking and hazard risk information . 27
B.1 Examples for marking . 27
B.2 Hazard risk information . 29
B.3 Measurement information . 30
B.3.1 Open running safety transformer. 30
B.3.2 65 VA safety transformer unloaded in a real series circuit . 31
B.3.3 100 VA safety transformer unloaded with a quasi-sinewave primary
current . 32
Annex C (informative) Additional information . 33
C.1 Determination of the peak voltage for SELV/PELV applications . 33
C.1.1 Standards used . 33
C.1.2 Reason for using . 33
C.2 Case I sinusoidal voltage (SELV, PELV) . 33
C.3 Case II current pulses . 37
Bibliography . 45

Figure 1 – Safety demarcation line in a safety extra low voltage system (SELV system) . 13
Figure 2 – Safety demarcation line in a protective extra-low voltage system
(PELV system) . 13
Figure 3 – Short-term non-recurring AC touch voltage limit . 16
Figure 4 – Short-term recurring peak touch voltage limit . 17
Figure 5 – Test setup for type tests without limiter . 21
Figure 6 – Test setup for type tests with limiter . 22
Figure 7 – Test setup for field tests without limiter . 24
Figure 8 – Test setup for field tests with limiter . 25
Figure B.1 – Example for marking (luminaire, bolt, cable) . 27
Figure B.2 – Example for marking tags . 27
Figure B.3 – Example for field marking (elevated luminaires) . 28
Figure B.4 – Example for field marking (inset luminaires) . 28
Figure B.5 – Example for field marking (cables) . 29
Figure B.6 – Example for field marking (CCRs) . 29
Figure B.7 – Current time effect diagram for alternating current 15 Hz to 100 Hz (for

ventricular fibrillation current pathway left hand to both feet) . 30
Figure B.8 – Principle voltage shape of an open running safety transformer (output
voltage) . 31
Figure B.9 – Voltage shape measured in a real circuit at an open running 65 W-
transformer with a series circuit voltage of 384 V AC RMS and series current of 4,1 A . 31
Figure B.10 – Voltage shape on the output of an unloaded safety transformer;

measured secondary voltage of 47,49 V AC RMS and a peak-to-peak voltage of 265 V . 32
Figure C.1 – Conventional time/current zones of effects of AC currents (15 Hz to
100 Hz) on persons for a current path corresponding to left hand to feet (see
Table C.2) . 35
Figure C.2 – Probability of fibrillation risks for current flowing in the path left hand to feet . 38
Figure C.3 – Extracted data from IEC 60479-2:2019, Figure 23 . 39
Figure C.4 – Modified IEC 60479-2:2019, Figure 23 . 40
Figure C.5 – Peak voltage vs peak impulse duration . 41

---------------------- Page: 5 ----------------------
– 4 – IEC 61820-3-4:2023 © IEC 2023
Figure C.6 – Peak voltage vs peak impulse duration with permissible (rectangular)
pulses . 42
Figure C.7 – Open secondary voltage peak . 42
Figure C.8 – Example – t vs t comparison . 44
erp max

Table A.1 – Comparison of characteristics of PELV and SELV . 26
Table C.1 – Total body impedances Z for a current path hand to hand for small
T
surface areas of contact in dry conditions at touch voltages U = 25 V to 200 V AC
T
50/60 Hz (values rounded to 25 Ω). 34
Table C.2 – Time/current zones for AC 15 Hz to 100 Hz for hand to feet pathway –
Summary of zones of Figure C.1 . 35
Table C.3 – Heart-current factor F for different current paths . 36
Table C.4 – Estimate for ventricular fibrillation threshold after each pulse of current in
a series of pulses each of which excited the heart tissue in such a manner as to
trigger ventricular responses . 39

---------------------- Page: 6 ----------------------
IEC 61820-3-4:2023 © IEC 2023 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________

ELECTRICAL INSTALLATIONS FOR
LIGHTING AND BEACONING OF AERODROMES –

Part 3-4: Safety secondary circuits in series circuits –
General safety requirements

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international
co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and
in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports,
Publicly Available Specifications (PAS) and Guides (hereafter referred to as "IEC Publication(s)"). Their
preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with
may participate in this preparatory work. International, governmental and non-governmental organizations liaising
with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for
Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence between
any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent
rights. IEC shall not be held responsible for identifying any or all such patent rights.
IEC 61820-3-4 has been prepared by IEC technical committee 97: Electrical installations for
lighting and beaconing of aerodromes. It is an International Standard.
The text of this International Standard is based on the following documents:
Draft Report on voting
97/253/FDIS 97/256/RVD

Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English.

---------------------- Page: 7 ----------------------
– 6 – IEC 61820-3-4:2023 © IEC 2023
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/publications.
A list of all parts in the IEC 61820 series, published under the general title Electrical installations
for lighting and beaconing of aerodromes, can be found on the IEC website.
Future documents in this series will carry the new general title as cited above. Titles of existing
documents in this series will be updated at the time of the next edition.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under webstore.iec.ch in the data related to the
specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.

IMPORTANT – The "colour inside" logo on the cover page of this document indicates
that it contains colours which are considered to be useful for the correct understanding
of its contents. Users should therefore print this document using a colour printer.

---------------------- Page: 8 ----------------------
IEC 61820-3-4:2023 © IEC 2023 – 7 –
INTRODUCTION
With a few exceptions, aeronautical ground lighting is designed for series circuit technology
operating with a constant current and a maximum input voltage of 5 000 V AC RMS, including
tolerances. The input voltage to the series circuit is constantly adjusted by the constant current
regulator to maintain the series circuit current irrespective of the variations in the load. The
properties and characteristics of the constant current regulators are provided in IEC 61822.
Due to the structure of the series circuit, i.e., a series connection of all loads, the usual
protective devices for personnel protection of an IT, TT or TN network cannot be applied.
Aeronautical ground lighting is defined as any light provided as an aid to air navigation and as
such is subject to specific requirements with respect to its resilience, availability, and
serviceability levels. Therefore, insulation faults in the series circuit are often tolerated, and do
not lead to the automatic disconnection of the electrical supply to the series circuit.
In view of the above, IEC 61821 states that no work of any kind is normally permitted on live
series circuits without first conducting a suitable and sufficient risk assessment and using
appropriate protective equipment according to IEC 61821.
The electrical characteristics of the constant current series circuits are often confused with
those of IT, TT or TN networks, i.e., constant input voltage, equipment connected in parallel,
and a load-dependent current. In practice, it is not always easy to assign rated voltages
correctly to individual components of the series circuit or to determine possible touch voltages.
In a constant current series circuit, the rated voltage of the equipment in the series circuit and
the maximum touch voltage frequently exceed the normal mains input voltage.
In a series circuit installation, the series circuit input voltage is divided in proportion to the
internal resistances of the various loads. The rated voltage, i.e., the voltage between the input
lines of the equipment, is defined by the series circuit current that flows through the equipment
and its input impedance. Since input impedance depends on the equipment design and the
series circuit current is constant, the input voltage remains the same for each item of equipment.
As a result of the provision of current control in the series circuit, the series circuit input voltage
is load-dependent and corresponds to the sum of all partial voltages in the series circuit.
This is different to determining the maximum possible touch voltage to earth in a series circuit.
Since one or more earth faults of varying resistance to earth may be present, the touch voltage
to earth may assume any value up to the maximum series circuit input voltage depending on
the location of the earth fault and the equipment installed in the series circuit. Therefore, when
determining the dielectric strength against earth potential, it is usual to take the maximum series
circuit input voltage. Such peculiarities of the series circuit have been considered in the
requirements for lamp systems in this document.
Since there are only a few effective safety features available for personnel protection in series
circuit technology, the protective measure "safety extra low voltage (SELV)" and "protective
extra low voltage (PELV)" is applied in this document for the supply of lamp systems. This
measure is common practice and can resort to the application of well-known and accepted
methodology. The introduction of SELV/PELV in this type of application has been made possible
by the introduction of new illumination technology that has lower power requirements and hence
requires a lower voltage supply.
NOTE This document is based on SELV specification according to IEC 60364-4-41 and IEC 61558-1.

---------------------- Page: 9 ----------------------
– 8 – IEC 61820-3-4:2023 © IEC 2023
ELECTRICAL INSTALLATIONS FOR
LIGHTING AND BEACONING OF AERODROMES –

Part 3-4: Safety secondary circuits in series circuits –
General safety requirements



1 Scope
This part of IEC 61820 specifies protective provisions for the operation of lamp systems
powered by series circuits in aeronautical ground lighting.
The protective provisions described here refer only to secondary supply systems for loads that
are electrically separated from the series circuit.
This document specifies the level of SELV, and alternatively PELV, under consideration of
additional personnel protection during work on live secondary circuits by electrically skilled
persons. This document also covers the special operational features of aeronautical ground
lighting and addresses the level of training and the requirements for maintenance procedures
detailed in IEC 61821 and other national or regional regulation.
The requirements and tests are intended to set a specification framework for system designers,
system installers, users, and maintenance personnel to ensure a safe and economic use of
electrical systems in installations for the beaconing of aerodromes.
This document complements existing IEC aeronautical ground lighting (AGL) standards and can
be used as a design specification.
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.
IEC 60364-4-41:2005, Low-voltage electrical installations – Part 4-41: Protection for safety –
Protection against electric shock
IEC 60417, Graphical symbols for use on e
...