IEC 63044-3:2017

IEC 63044-3 ®
Edition 1.1 2021-05
CONSOLIDATED VERSION
INTERNATIONAL
STANDARD
colour
inside
Home and building electronic systems (HBES) and building automation and
control systems (BACS) –
Part 3: Electrical safety requirements

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.

IEC Central Office Tel.: +41 22 919 02 11
3, rue de Varembé info@iec.ch
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 online collection - oc.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and withdrawn publications.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 22 000 terminological entries in English
details all new publications released. Available online and once
and French, with equivalent terms in 18 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: sales@iec.ch.
IEC 63044-3 ®
Edition 1.1 2021-05
CONSOLIDATED VERSION
INTERNATIONAL
STANDARD
colour
inside
Home and building electronic systems (HBES) and building automation and

control systems (BACS) –
Part 3: Electrical safety requirements

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.120.01; 29.120.99 ISBN 978-2-8322-9781-0

IEC 63044-3 ®
Edition 1.1 2021-05
CONSOLIDATED VERSION
REDLINE VERSION
colour
inside
Home and building electronic systems (HBES) and building automation and
control systems (BACS) –
Part 3: Electrical safety requirements

– 2 – IEC 63044-3:2017+AMD1:2021 CSV
© IEC 2021
CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 6
2 Normative references . 6
3 Terms, definitions and abbreviated terms . 7
3.1 Terms and definitions . 7
3.2 Abbreviated terms . 10
4 Classification of HBES/BACS network interfaces Void . 10
5 Safety requirements and compliance criteria. 10
6 Requirements . 11
6.1 General . 11
6.2 Classification requirements of installation areas . 11
6.2.1 Overvoltage category . 11
6.2.2 Pollution degree . 11
6.2.3 Material class . 11
6.3 Electrical safety requirements . 11
6.3.1 Protection from hazards in the device . 11
6.3.2 Protection from overvoltage on the network and from hazards caused by
different types of of circuit network . 12
6.3.3 Protection from touch current . 14
6.3.4 Protection of the communication wiring from overheating . 16
6.4 Installation . 16
Annex A (informative) List of product standards for electrical safety . 17
Bibliography . 19

Table 1 – Requirements for connection of devices to a dedicated HBES/BACS network. 12

© IEC 2021
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
HOME AND BUILDING ELECTRONIC SYSTEMS (HBES) AND
BUILDING AUTOMATION AND CONTROL SYSTEMS (BACS) –

Part 3: Electrical 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.
This consolidated version of the official IEC Standard and its amendment has been
prepared for user convenience.
IEC 63044-3 edition 1.1 contains the first edition (2017-01) [documents 23/735/CDV and
23/747/RVC] and its amendment 1 (2021-05) [documents 23/912/CDV and 23/961A/RVC].
In this Redline version, a vertical line in the margin shows where the technical content
is modified by amendment 1. Additions are in green text, deletions are in strikethrough
red text. A separate Final version with all changes accepted is available in this
publication.
– 4 – IEC 63044-3:2017+AMD1:2021 CSV
© IEC 2021
International Standard IEC 63044-3 has been prepared by IEC technical committee 23:
Electrical accessories.
A list of all parts in the IEC 63044 series, published under the general title Home and Building
Electronic Systems (HBES) and Building Automation Control Systems (BACS), can be found
on the IEC website.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
In this publication, the following print types are used:
– Requirements proper: in roman type.
– Test specifications: in italic type.
This document shall be used in conjunction with relevant product safety standards.
The committee has decided that the contents of the base publication and its amendment will
remain unchanged until the stability date indicated on the IEC web site under
"http://webstore.iec.ch" in the data related to the specific publication. At this date, the
publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
IMPORTANT – The 'colour inside' logo on the cover page of this publication 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.
© IEC 2021
INTRODUCTION
The IEC 63044 series deals with developing and testing Home and Building Electronic
Systems (HBES) and Building Automation and Control Systems (BACS).
This document deals with electrical safety requirements for HBES/BACS.
This document is based on the philosophy that a device considered electrically safe according
to an appropriate product safety standard should also remain safe when connected to a
network. This document specifies in addition to the specific product standard the electrical
safety requirements necessary in order for an HBES/BACS device connected to a network to
remain safe under normal and single-fault conditions of the HBES/BACS network and at the
same time under normal and single-fault conditions of one or more HBES/BACS devices
connected to the HBES/BACS network. This includes protection from overvoltages on the
network, protection from hazards caused by connection of different types of circuit network,
the limitation of the touch current to a network and protection of the communication wiring
from overheating.
The HBES/BACS network is any interconnection between HBES/BACS products devices. The
HBES/BACS networks can be either an ICT network with interfaces classified according to
IEC 62949 or a dedicated network classified as a mains, ELV, FELV, SELV or PELV circuit
network.
For HBES/BACS products devices connected to an ICT network, the requirements in
IEC 62949 apply.
For HBES/BACS products devices connected to a dedicated HBES/BACS network, the
requirements for the electrical separation between the device and the network circuit are
specified (see Table 1). These specifications of the electrical separations follow the principle
in the basic safety publications IEC 60664-1 and IEC 61140, together with the installation
requirements of IEC 60364. The following compromises are used.
– According to the principles of IEC 60664-1, the rated impulse voltage for the separation
shall be the higher of the impulse voltage on the network and the rated impulse voltage of
the device circuit to be connected to the network.
– The overvoltage categories considered by IEC 60664-1 refer to overvoltages derived
directly from the mains through the power supply.
– The overvoltages coming from other sources (e.g. capacitive couplings) are not specified
in IEC 60664-1. IEC 60664-1 recommends that technical committees specify overvoltage
categories or rated impulse voltages as appropriate.
For the purposes of this document, the following impulse voltages have been specified.
• For networks with galvanic electrical separation from mains (FELV, SELV or PELV circuit),
the impulse overvoltage coming from the network side of the separation has been limited
to 2,5 kV for fixed installed networks and 1,5 kV for detachable networks.
• For ICT networks, particular requirements apply (see 6.3.2.1).

– 6 – IEC 63044-3:2017+AMD1:2021 CSV
© IEC 2021
HOME AND BUILDING ELECTRONIC SYSTEMS (HBES) AND
BUILDING AUTOMATION AND CONTROL SYSTEMS (BACS) –

Part 3: Electrical safety requirements

1 Scope
This part of IEC 63044 provides the electrical safety requirements related to the HBES/BACS
network in addition to the product safety standards for HBES/BACS devices.
It also applies to devices used within an HBES/BACS network for which no specific
HBES/BACS product safety standard exists.
This document specifies the electrical safety requirements for HBES/BACS.
In addition, it defines safety requirements for the interface of equipment intended to be
connected to an HBES/BACS network. It does not apply to interfaces to other networks.
NOTE An example of other networks is a dedicated ICT network covered by IEC 62949.
This document is applicable to
– operator stations and other human–system interface devices,
– devices for management functions,
– control devices, automation stations and application-specific controllers,
– field devices and their interfaces, and
– cabling and interconnection of devices
used within a dedicated HBES/BACS network.
This document covers the following requirements and compliance criteria:
• protection from against hazards in from the device;
• protection from against overvoltages on the network;
• protection from against touch current;
• protection from against hazards caused by different types of circuit network;
• protection of the communication wiring from against overheating caused by excessive
current.
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 60038:2009, IEC standard voltages
IEC 60364 (all parts), Low-voltage electrical installations

© IEC 2021
IEC 60364-5-52, Low-voltage electrical installations – Part 5-52: Selection and erection of
electrical equipment – Wiring systems
IEC 60664-1, Insulation coordination for equipment within low-voltage systems – Part 1:
Principles, requirements and tests
IEC 60664-1:2007, Insulation coordination for equipment within low-voltage systems – Part 1:
Principles, requirements and tests
IEC 61180, High-voltage test techniques for low-voltage equipment –Definitions, test and
procedure requirements, test equipment
IEC 62151:2000, Safety of equipment electrically connected to a telecommunication network
IEC 62949, Particular safety requirements for equipment to be connected to information and
communication networks
IEC 63044-1, Home and Building Electronic Systems (HBES) and Building Automation and
Control Systems (BACS) – Part 1: General requirements
3 Terms, definitions and abbreviated terms
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 63044-1 and the
following apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1.1
ICT network
information and communication technology network
metallically terminated transmission medium consisting of two conductors intended for
communication between equipment that may be located in separate buildings, excluding:
– the mains system for supply, transmission and distribution of electrical power, if used as a
communication transmission medium;
– dedicated HBES/BACS networks;
– external circuits networks using ES1 connecting units of audio/video, information and
communication technology equipment
Note 1 to entry: This may include twisted pairs, and may include circuits networks which are subjected to
transients as indicated in Table 14, ID1 of IEC 62368-1:2014 (assumed to be 1,5 kV).
Note 2 to entry: An ICT network may be:
– publicly or privately owned;
– subject to transient overvoltages due to atmospheric discharges and faults in power distribution systems;
– subject to longitudinal (common mode) voltages induced from nearby power lines or electric traction lines.
Note 3 to entry: Examples of ICT networks are:

Under preparation. Stage at the time of publication: IEC/FDIS 62949:2016.

– 8 – IEC 63044-3:2017+AMD1:2021 CSV
© IEC 2021
– a public switched telephone network;
– a public data network;
– an Integrated Services Digital Network (ISDN);
– a private network with electrical interface characteristics similar to the above.
Note 4 to entry: For information about circuit network voltages and signals which may be present, see Annex B of
IEC 60950-1:2005.
3.1.2
electric shock
physiological effect resulting from an electric current through a human or animal body
[SOURCE: IEC 60050-195:1998, 195-01-04]
3.1.3
basic protection
protection against electric shock under fault-free conditions
[SOURCE: IEC 60050-195:1998, 195-06-01]
3.1.4
fault protection
protection against electric shock under single-fault conditions
[SOURCE: IEC 60050-195:1998, 195-06-02]
3.1.5
mains
power supply system with nominal voltage according Table 1 of IEC 60038:2009
3.1.6
mains circuit network
electrical circuit network in which the nominal voltage cannot exceed mains voltage under
normal conditions
3.1.7
extra low voltage
ELV
nominal voltage in the electrical installation of buildings according to the voltage band I
specified in IEC 61140
Note 1 to entry: Voltage band I according to IEC 61140 is a voltage below or equal to 50 V AC or 120 V DC.
3.1.8
extra low voltage circuit network
ELV circuit network
electrical circuit network in which the nominal voltage cannot exceed ELV under normal
conditions
Note 1 to entry: An ELV circuit network is not safe to touch.
3.1.9
functional extra low voltage circuit network
FELV circuit network
electrical circuit network in which the nominal voltage cannot exceed ELV under normal
conditions
Note 1 to entry: FELV has simple separation from mains.
Note 2 to entry: A FELV circuit network is not safe to touch and may be connected to protective earth.

© IEC 2021
3.1.10
safety extra low voltage circuit network
SELV circuit network
electrical circuit network in which the nominal voltage cannot exceed ELV
– under normal conditions,
– under single-fault conditions, including earth fault in other circuits networks
Note 1 to entry: SELV has simple separation from PELV and other SELV systems, and earth and protective
separation from all other circuits networks.
Note 2 to entry: Under normal conditions and single-fault conditions in a dry location inside a building, a SELV
circuit network with a voltage not higher than 25 V AC or 60 V DC is safe to touch.
3.1.11
protective extra low voltage circuit network
PELV circuit network
electrical circuit network in which the nominal voltage cannot exceed ELV
– under normal conditions,
– under single-fault conditions, except earth fault in other circuits networks
Note 1 to entry: PELV has protective separation from all circuits networks other than PELV, SELV or earth.
Note 2 to entry: PELV circuit network is safe to touch within the same equipotential bonding area inside a building
under the following conditions: under normal and single-fault conditions in dry locations and with no large contact
area with a voltage not higher than 25 V AC or 60 V DC; otherwise not higher than 12 V AC or 30 V DC.
3.1.12
simple separation
separation between circuits networks or between a circuit network and earth by means of
basic insulation
3.1.13
protective separation
separation of one electric circuit network from another by means of
– double insulation, or
– basic insulation and electrically protective screening (shielding), or
– reinforced insulation
[SOURCE: IEC 60050-195:1998, 195-06-19, modified – "(electrically)" has been omitted from
the term and "circuit" has been replaced with "network" in the definition.]
3.1.14
basic insulation
insulation of hazardous-live parts which provides basic protection
[SOURCE: IEC 60050-826:2004, 826-12-14]
3.1.15
double insulation
insulation comprising both basic insulation and supplementary insulation
[SORCE: IEC 60050-195:1998, 195-06-08]
3.1.16
supplementary insulation
independent insulation applied in addition to basic insulation for fault protection
[SOURCE: IEC 60050-826:2004, 826-12-15]

– 10 – IEC 63044-3:2017+AMD1:2021 CSV
© IEC 2021
3.1.17
electrically protective screening
separation of electric circuits networks or conductors from hazardous-live parts by an
electrically protective screen (shield) connected to the protective-equipotential-bonding
system and intended to provide protection against electric shock
[SOURCE: IEC 60050-195:1998, 195-06-18, modified – "circuits" has been replaced with
"networks" in the definition.]
3.1.18
reinforced insulation
insulation of hazardous-live-parts which provides a degree of protection against electric shock
equivalent to double insulation
[SOURCE: IEC 60050-826:2004, 826-12-17]
3.2 Abbreviated terms
For the purposes of this document, the abbreviated terms given in IEC 63044-1 and the
following apply.
ELV Extra Low Voltage
FELV Functional Extra Low Voltage
SELV Safety Extra Low Voltage
PELV Protective Extra Low Voltage
4 Classification of HBES/BACS network interfaces Void
4.1 General
HBES/BACS networks can be based on the following networks.
4.2 ICT network
The classification of interfaces for devices to be connected to information and communication
technology networks given in IEC 62949 applies.
4.3 Dedicated network
The classification of interfaces for devices to be connected to a dedicated network is LV, ELV,
FELV, SELV or PELV circuit.
5 Safety requirements and compliance criteria
This document shall be used together with the appropriate electrical safety standard for the
device to be part of the HBES/BACS. See Table 1 Annex A.
This document applies in the following way.
a) If the safety standard for the device to be part of the HBES/BACS does not specify
electrical safety requirements for HBES/BACS, this document (IEC 63044-3) applies.
b) If the safety standard for the device to be part of the HBES/BACS specifies electrical
safety requirements for HBES/BACS, the requirements of this document (IEC 63044-3)
shall be used as the minimum levels required.

© IEC 2021
6 Requirements
6.1 General
The entire HBES/BACS, media and devices as well as their installation, shall ensure safe
operation by protection against mechanical, chemical, environmental and other hazards and
protection against electric shock, burns and fire during normal use as well as under specified
abnormal conditions.
The entire HBES/BACS, media and devices as well as their installation, shall ensure safe
operation and protection against electric shock, burns and fire during normal use as well as
under single-fault conditions.
Compliance is checked by the classification requirements of installation areas in 6.2, the
electrical safety requirements in 6.3 and the installation requirements in 6.4.
6.2 Classification requirements of installation areas
6.2.1 Overvoltage category
Devices to be installed as a part of the fixed installation of an HBES/BACS system shall be
classified as overvoltage category III according to IEC 60664-1.
Devices that are not part of the fixed installation but to be supplied from the fixed installation
of an HBES/BACS shall be classified at least as overvoltage category II according to
IEC 60664-1.
Compliance is checked by inspection of the product descriptions and/or installation
instructions.
6.2.2 Pollution degree
All devices of an HBES/BACS system shall be classified at least for pollution degree 2
according to IEC 60664-1.
Compliance is checked by inspection of the product descriptions and/or installation
instructions.
6.2.3 Material class
All devices of an HBES/BACS shall comply with the minimum material class IIIa (CTI = 175
V).
6.3 Electrical safety requirements
6.3.1 Protection from hazards in the device
Devices of an HBES/BACS shall comply with the electrical safety requirements in the
appropriate product standard in consideration of the required overvoltage category and
pollution degree specified in 6.2.1 and 6.2.2.
An informative non-exhaustive list of product standards for electrical safety is provided in
Annex A.
Compliance is checked by the requirements in the relevant product standard.

– 12 – IEC 63044-3:2017+AMD1:2021 CSV
© IEC 2021
6.3.2 Protection from overvoltage on the network and from hazards caused by
different types of circuit network
6.3.2.1 HBES/BACS products devices connected to an ICT network
For HBES/BACS products devices connected to an ICT network, as defined in 3.1.4 3.1.1, the
appropriate requirements in IEC 62949 apply in addition to the product standard.
Compliance is checked by the requirements and tests according to IEC 62949.
6.3.2.2 Products connected to Devices interconnected via a dedicated HBES/BACS
network
For products connected to a dedicated HBES/BACS network, as classified in 4.3, the
protection against electric shock in accordance with 6.3.1 applies. Table 1 specifies the
required electrical separation between the device circuit and the HBES/BACS network circuit
and applies in addition to the product standard.
For devices connected to an HBES/BACS network as defined in IEC 63044-1:2017, 3.1.2 and
IEC 63044-1:2017/AMD1:2021, 3.1.2, the protection against electric shock in accordance with
6.3.1 applies. Table 1 specifies the required electrical separation between the device network
and the HBES/BACS network and applies in addition to the product standard.
If the separation between the mains and SELV is done with a transformer, this shall be a
safety transformer according to IEC 61558-2-6 or IEC 61558-2-16.
NOTE Table 1 can also be used as guidance for the separation between different circuits within a device in case
the relevant product standard does not specify these requirements.
The relevant information about the safety classification (overvoltage category and type of
circuit) of the ports and any restrictions applicable (e.g. the network topology) shall be stated
in the manufacturer’s documentation.
Table 1 – Requirements for connection of devices to a dedicated HBES/BACS network
HBES/BACS network circuit (overvoltage category III)

Mains ELV FELV SELV PELV
a
Voltage range V AC ≤ 230 ≤ 50 ≤ 50 ≤ 50 ≤ 50
a
Voltage range V DC ≤ 400 ≤ 120 ≤ 120 ≤ 120 ≤ 120
Device circuits
(overvoltage category III
Requirement for the electrical separation between the HBES/BACS
or II) other than the
b
network circuit and other device circuits
HBES/BACS network
circuit
d
None Functional Simple Protective Protective
A 230 V A 230 V A 230 V A 230 V
Mains
B - B 1,5 kV B 3,0 kV B 3,0 kV
≤ 230 V AC/400 V DC
C 4 kV C 4 kV C 6 kV C 6 kV
D 2,5 kV D 2,5 kV D 4 kV D 4 kV
d
Functional None Simple Protective Protective
A 230 V A 230 V A 230 V A 230 V
ELV
B - B 1,5 kV B 3,0 kV B 3,0 kV
≤ 50 V AC/120 V DC
C 4 kV C 4 kV C 6 kV C 6 kV
D 2,5 kV D 2,5 kV D 4 kV D 4 kV
c d f f
Simple Simple Functional Simple Simple
FELV
A 230 V A 230 V A 50 V A 230 V A 230 V

© IEC 2021
≤ 50 V AC/120 V DC B 1,5 kV B 1,5 kV B - B - B -
C 4 kV C 4 kV C 2,5 kV C 4 kV C 4 kV
D 2,5 kV D 2,5 kV D 1,5 kV D 2,5 kV D 2,5 kV
f c
Protective Protective Simple Simple Simple
A 230 V A 230 V A 230 V A 50 V A 50 V
SELV
B 3,0 kV B 3,0 kV C 4 kV B - B -
≤ 50 V AC/120 V DC
e e
C 6 kV C 6 kV D 2,5 kV C 2,5 kV C 2,5 kV
D 4 kV D 4 kV D 1,5 kV D 1,5 kV
f c
Protective Protective Simple Simple Simple
A 230 V A 230 V A 230 V A 50 V A 50 V
PELV
≤ 50 V AC/120 V DC B 3,0 kV B 3,0 kV B - B - B -
e e
earthing C 6 kV C 6 kV C 4 kV C 2,5 kV C 2,5 kV
D 4 kV D 4 kV D 2,5 kV D 1,5 kV D 1,5 kV
a
Values according to IEC 60664-1. Voltages are nominal.
b
Requirements for the insulation:
A = Rated insulation AC voltage (r.m.s.) for the electrical separation;
B = Test AC voltage (r.m.s.) for the electrical separation due to temporary overvoltage;
C = Rated impulse voltage for the electrical separation for devices classified as overvoltage category III;
D = Rated impulse voltage for the electrical separation for devices classified as overvoltage category II.
Impulse tests for C and D according to IEC 61180 (1,2 µs / 50 µs impedance 42 Ω).
c
A SELV device circuit and a SELV network circuit of the same rated voltage and overvoltage category can be considered
as the same circuit and therefore no separation is needed.
A PELV device circuit and a PELV network circuit of the same rated voltage and overvoltage category can be considered
as the same circuit and therefore no separation is needed.
A FELV device circuit and a FELV network circuit of the same rated voltage and overvoltage category can be considered
as the same circuit and therefore no separation is needed.
d
Functional means functional separation for the highest voltage present.
e
When the HBES/BACS is installed wholly within an equipotential earthing system, the values C and D can be reduced to
800 V and 500 V, respectively.
f
This separation covers also the required protective separation between FELV and SELV or PELV circuits.

Compliance with the required electrical separation between the device circuit and the
HBES/BACS network circuit shall be tested in accordance with the test requirements in the
specific product standard with the appropriate test levels specified in Table 1 under the
following conditions.
– If the electrical separation (simple and protective separation) has a creepage distance, the
voltage specified by the letter A shall be used for dimension of the creepage distance.
However this creepage distance shall not be less than the clearance for the electrical
separation.
– If the electrical separation (simple and protective separation) has a clearance and/or a
solid insulation, the voltage specified by the letters B and either C or D shall be used for
dimension of the clearance and/or the solid insulation.
– If the product standard has no test requirements for the impulse voltage test, the
requirement specified Table 12 Table 1 shall be used.
– The test voltage related to the rated impulse voltage, when used for testing the
clearances, shall be corrected according to corresponding test altitudes according to
IEC 60664-1. If clearances have been chosen for inhomogeneous field conditions
according to IEC 60664‑1:2007, Table F.2, no verification by a voltage withstand test is
needed.
– As an alternative to the impulse voltage test of IEC 60664-1:2007 (6.1.2.2.1), the dielectric
test with AC voltage (6.1.2.2.2.2) or the dielectric test with DC voltage (6.1.2.2.2.3) may
be used.
– 14 – IEC 63044-3:2017+AMD1:2021 CSV
© IEC 2021
6.3.3 Protection from touch current
6.3.3.1 General
NOTE Products Devices complying with IEC 62368-1 fulfil the requirements.
If the nominal voltage exceeds 25 V AC or 60 V DC or if the equipment is immersed, basic
protection shall be provided for SELV and PELV circuits by insulation or barriers or
enclosures.
Basic protection is generally unnecessary in normal dry conditions for
– SELV circuits where the nominal voltage does not exceed 25 V AC or 60 V DC, and
– PELV circuits where the nominal voltage does not exceed 25 V AC or 60 V DC and
exposed-conductive-parts and/or the live parts are connected by a protective conductor to
the main earthing terminal.
In all other cases, basic protection is not required if the nominal voltage of the SELV or PELV
system does not exceed 12 V AC or 30 V DC.
Compliance is checked by measurement of the voltage and, if relevant, by testing the basic
protection according to the product standard.
If no product standard exist, the test voltage for basic protection shall be 500 V.
6.3.3.2 HBES/BACS products connected Limitation of touch current from the
HBES/BACS device to an ICT network
For HBES/BACS products devices connected to an ICT network, as classified in 4.2 defined in
3.1.1, the appropriate requirements in IEC 62949 apply in addition to the product standard.
6.3.3.3 Limitation of the touch current from the device to the dedicated HBES/BACS
network
The touch current from devices supplied from the mains supply to the HBES/BACS network
shall be limited to 0,25 mA r.m.s. according to IEC 62151:2000, 5.4.
Compliance is checked by measurement according to the test circuits in Figures 5 and 6 in
IEC 62151:2000.
This test does not apply to devices where the circuit to be connected to the HBES/BACS
network is connected to the protective or functional earthing terminal in the device. In this
case the touch current from the device to the network is considered to be zero.
6.3.3.4 Summation of touch current
6.3.3.4.1 General
A device that provides an HBES/BACS network connection for connection of multiple items of
other HBES/BACS equipment shall not create a hazard due to summation of touch current.
NOTE The background for these requirements is explained in IEC 60950-1:2005, Annex W. The values used for
these requirements are taken from IEC 61140:2016.
In these requirements, abbreviations have the following meanings:
– I is the touch current received from other equipment via a network at a port of the device;
– I is the summation of touch currents received from other equipment at all such
∑ 1
network ports of the device;
© IEC 2021
– I is the touch current due to the AC mains supply of the device.
It shall be assumed that each HBES/BACS network port receives 0,25 mA (I ) from the other
devices, unless the actual current from the other equipment is known to be lower. The
following requirements, 6.3.3.4.2 or 6.3.3.4.3 as applicable, shall be met.
6.3.3.4.2 Devices with earthed network ports
For a device in which each network port is connected to the main protective earthing terminal
of the device, the following items 1) and 2) shall be considered.
1) If I (not including I ) exceeds 3,5 mA AC RMS or 10 mA ripple-free DC,
∑ 1 2
– the equipment shall have provision for a permanent connection to protective earth in
addition to the protective earthing conductor in the power supply cord if any, and
– the installation instructions shall specify the provision of a permanent connection to
protective earth with a cross-sectional area of not less than 2,5 mm , if mechanically
protected, or otherwise 4,0 mm , and
– a label with the following wording or similar wording shall be affixed adjacent to the
permanent earth connection:
WARNING
HIGH TOUCH CURRENT
EARTH CONNECTION ESSENTIAL
BEFORE MAKING NETWORK
CONNECTIONS
2) I plus I shall comply with the limits, if any, in the relevant product safety standard.
∑ 1 2
Compliance with item 1) is checked by inspection and if necessary by the following test.
If the equipment has provision for a permanent protective earth connection in accordance with
item 1) above, it is not necessary to make any measurements, except that I shall comply with
the relevant requirements of the product safety standard.
Touch current tests, if necessary, are made using the relevant measuring instrument
described in IEC 60990 or any other instrument giving the same results. A capacitive coupled
AC source of the same line frequency and phase as the AC mains supply is applied to each
communication port such that 0,25 mA, or the actual current from other devices if known to be
lower, is available to flow into that communication port. The current flowing in the earthing
conductor is then measured.
6.3.3.4.3 Devices whose network ports have no reference to protective earth
If the network ports on the device do not have a common connection, each communication
port shall comply with the requirements for touch current in IEC 62949.
If all communication ports or any groups of such ports have a common connection including a
from each common connection shall not exceed
network segment, the total touch current
3,5 mA.
Compliance is checked by inspection and if necessary by the tests of EN 41003 or, if there
are common connection points, by the following test.
A capacitive coupled AC source of the same frequency and phase as the AC mains supply is
applied to each communication port such that 0,25 mA, or the actual current from the other if
known to be lower, is available to flow into that communication port. Common connection
points are tested whether or not the points are accessible.

– 16 – IEC 63044-3:2017+AMD1:2021 CSV
© IEC 2021
6.3.4 Protection of the communication wiring from overheating
In addition to the control function, the network may provide a power supply function. To make
sure that the communication cable is protected from overheating, the power supply shall have
a short circuit and/or overload current limitation. The current-carrying capacity for the
communication wires shall be at least equal to the total current limitation for the connected
power supplies.
The temperature limits and current-carrying capacities for the communication wires specified
in IEC 60364-5-52 shall not be exceeded.
Compliance is checked by inspection and measurement.
6.4 Installation
Installation of a home and building automation and control system shall comply with
IEC 60364 (all parts) and manufacturer installation instructions.
NOTE Additional national requirements may apply.

© IEC 2021
Annex A
(informative)
List of product standards for electrical safety
Device type Relevant standard Title
Management devices
Data processing devices IEC 62368-1 Audio/video, information and
(Server stations) communication technology
equipment − Part 1: Safety
requirements
Peripherals IEC 62368-1 Audio/video, information and
(Storage and archiving devices, visual display communication technology
units, printers)
equipment − Part 1: Safety
requirements
Interfaces IEC 62368-1 Audio/video, information and
(Data Interface Unit (DIU), interfaces to communication technology
Dedicated Special Systems (DSS))
equipment − Part 1: Safety
requirements
Alarm indication and annunciation devices IEC 62080 Sound signalling devices for
(Acoustic annunciation devices, optical indication household and similar purposes
device)
IEC 62094-1 Indicator light units for household and
similar fixed-electrical installations −
Part 1: General requirements
IEC 60598 series Luminaires
Control devices
Controllers and automation stations IEC 60730-1 Automatic electrical controls −
Part 1: General requirements
Application Specific Controllers (ASC) IEC 60730-1
Automatic electrical controls −
Part 1: General requirements
Field devices
Coupling modules IEC 60730-1 Automatic electrical controls −
Part 1: General requirements
Local override / indication devices IEC 60730-1
Automatic electrical controls −
Part 1: General requirements
Sensors IEC 60730-1 Automatic electrical controls −
Part 1: General requirements
Actuators IEC 60730-2-14 Automatic electrical controls for
household and similar use −
Part 2-14: Particular requirements for
electric actuators
Room devices, operator panels (HMIs) IEC 60730-1 Automatic electrical controls −
Part 1: General requirements
Thermostats IEC 60730-2-9 Automatic electrical controls –
Part 2-9: Particular requirements for
temperature sensing control
Uninterruptible Power Systems (UPS) IEC 62040 series Uninterruptible power systems (UPS)
Electronic switches and associated electronic IEC 60669-2-1 Switches for household and similar
extension units for household and similar fixed
fixed electrical installations −
electrical installations Part 2-1: Particular
requirements − Electronic switches
IEC 60669-2-5 Switches for household and similar
fixed electrical installations −
Part 2-5: Particular
requirements − Switches and related
accessories for use in home and
building electronic systems (HBES)
Power transformers, power supply units and IEC 61558 series Safety of transformers, reactors,
similar devices power supply units and combinations
thereof
– 18 – IEC 63044-3:2017+AMD1:2021 CSV
© IEC 2021
Device type Relevant standard Title
Adjustable speed electrical power drive systems IEC 61800 series Adjustable speed electrical power
drive systems
Audio/video equipment IEC 62368-1 Audio/video, information and
communication technology
equipment −
...