SIST HD 60364-4-43:2023/kFprAA:2026

• Abstract:

  IEC 60364-4-43:2023 provides requirements for: - protection of live conductors, PEN conductors, PEM conductors, and PEL conductors against the harmful effects caused by overcurrent; - coordination of measures for protection against overcurrent. This fourth edition cancels and replaces the third edition published in 2008. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: a) the standard has been restructured, see Table 1 (Correspondence between IEC 60364‑4‑43:2008 and this document) below; b) the measure "automatic disconnection of supply" has been designated as the preferred measure for protection against overcurrent; c) all measures except the measure "automatic disconnection of supply" have been transferred into new normative annexes to indicate that these measures are usable in certain applications and under certain restricted conditions only (see Annex A, Annex B and Annex E); d) a new clause "Terms and definitions" has been added; e) new requirements have been added for the protection of the neutral or mid-point conductor (with and without triplen harmonics).

• Status: Not Published
• Public Enquiry End Date: 30-Jul-2025
• ICS: 29.120.50 - Fuses and other overcurrent protection devices
• ICS: 91.140.50 - Electricity supply systems
• Technical Committee: ELI - Electrical and communication installations
• Current Stage: 5020 - Formal vote (FV) (Adopted Project)
• Start Date: 10-Sep-2026
• Due Date: 29-Oct-2026
• Completion Date: 10-Sep-2026
• Ref Project: HD 60364-4-43:2023/FprAA:2026 - Low-voltage electrical installations - Part 4-43: Protection for safety - Protection against overcurrent

• Amends: SIST HD 60364-4-43:2023 - Low-voltage electrical installations - Part 4-43: Protection for safety - Protection against overcurrent (IEC 60364-4-43:2023)
• Effective Date: 09-Apr-2024

Overview

SIST HD 60364-4-43:2023/kFprAA:2026 outlines essential requirements for low-voltage electrical installations with a focus on protection for safety against overcurrents. Developed by SIST and harmonized at the European level, this standard provides a framework to safeguard live conductors, including PEN, PEM, and PEL types, from the harmful effects of overcurrent situations such as overloads and short circuits. The 2023 edition represents a technical revision, aligning its structure and terminology more closely with current best practices and introducing updated requirements to ensure electrical safety and reliability.

Key Topics

• Protection Against Overcurrent: Specifies measures to prevent damage or hazards due to excessive current, including both overload and short-circuit scenarios.
• Positioning of Protection Devices: Establishes where overcurrent protection devices, such as fuses or circuit breakers, should be installed:
  • At each circuit origin unless exceptions apply.
  • At points with changes in conductor capacity or material, and where conductor protection is required.
• Automatic Disconnection of Supply: Designated as the preferred measure for mitigating overcurrent risks, enhancing rapid response to dangerous conditions.
• Exceptional Installations: Provides annexes for specialized measures usable in non-standard applications or under constrained conditions, such as IT systems.
• Special National Conditions: Recognizes country-specific rules and practices (e.g., in Italy, Germany, UK), ensuring local regulatory compliance while maintaining core safety requirements.
• Coordination Requirements: Addresses the need for coordination between various overcurrent protection methods and devices to assure comprehensive safeguarding.

Applications

The standard is directly relevant for:

• Electrical Designers and Installers: Ensures correct placement and selection of overcurrent protection devices in domestic, commercial, and industrial low-voltage systems.
• Safety Inspectors and Auditors: Provides a benchmark for evaluating compliance of electrical installations with recognized safety practices.
• Utility Providers: Informs practices regarding main distribution protection and specific exceptions, including circumstances where utility-installed devices may serve as the sole protection upstream from main distribution points.
• Construction and Maintenance: Guides the safe modification or extension of existing installations, especially where changes to conductor types, capacities, or configurations arise.
• Special Applications: Offers clarification for installations in environments with increased risk (e.g., fire hazards, explosive atmospheres), and for specialized distribution systems without a neutral conductor.

Related Standards

Understanding and applying SIST HD 60364-4-43:2023/kFprAA:2026 is enhanced by reference to related documents, such as:

• IEC 60364-4-43:2023: International base standard for overcurrent protection in low-voltage electrical installations.
• HD 60364-4-43:2023: European harmonization document, forming the backbone for national adoption in EU and EEA states.
• CEI 0-21 (Italy): Specifies allowable short-circuit currents at grid supply points for Italian installations.
• IEC 60364-5-53/HD 60364-5-53: Concerns selection and erection of electrical equipment, including devices for isolation, switching, and control, which are crucial for network protection.
• National Wiring Regulations: Such as BS 7671 (UK), DIN VDE standards (Germany), and relevant country-specific rules referenced in Annex ZB and ZC for compliance with local legal requirements.

Choosing and installing the right overcurrent protection according to SIST HD 60364-4-43:2023/kFprAA:2026 ensures electrical safety, compliance, and system durability across diverse low-voltage installations. This standard is integral to reducing risks, meeting legal obligations, and aligning with European and international best practices in electrical engineering.

SLOVENSKI STANDARD
SIST HD 60364-4-43:2023/oprAA:2025
01-julij-2025
Nizkonapetostne električne inštalacije - 4-43. del: Zaščitni ukrepi - Zaščita pred
nadtoki - Dopolnilo AA
Low-voltage electrical installations - Part 4-43: Protection for safety - Protection against
overcurrent
Errichten von Niederspannungsanlagen - Teil 4-43: Schutzmaßnahmen - Schutz bei
Überstrom
Installations électriques à basse tension - Partie 4-43: Protection pour assurer la sécurité
- Protection contre les surintensités
Ta slovenski standard je istoveten z: HD 60364-4-43:2023/prAA:2025
ICS:
29.120.50 Varovalke in druga Fuses and other overcurrent
nadtokovna zaščita protection devices
91.140.50 Sistemi za oskrbo z elektriko Electricity supply systems
SIST HD 60364-4-43:2023/oprAA:2025 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

SIST HD 60364-4-43:2023/oprAA:2025

SIST HD 60364-4-43:2023/oprAA:2025

HARMONIZATION DOCUMENT DRAFT
HD 60364-4-43:2023
DOCUMENT D'HARMONISATION
HARMONISIERUNGSDOKUMENT
prAA
June 2025
ICS 91.140.50; 29.120.50 -
English Version
Low-voltage electrical installations - Part 4-43: Protection for
safety - Protection against overcurrent
Installations électriques à basse tension - Partie 4-43: Errichten von Niederspannungsanlagen - Teil 4-43:
Protection pour assurer la sécurité - Protection contre les Schutzmaßnahmen - Schutz bei Überstrom
surintensités
This draft amendment prAA, if approved, will modify the Harmonization Document HD 60364-4-43:2023; it is submitted to CENELEC
members for enquiry.
Deadline for CENELEC: 2025-08-29.

It has been drawn up by CLC/TC 64.

If this draft becomes an amendment, CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which
stipulate the conditions for implementation of this amendment on a national level.

This draft amendment, was established by CENELEC in three official versions (English, French, German).

CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the
Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Türkiye and the United Kingdom.

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

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

European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2025 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Project: 79835 Ref. No. HD 60364-4-43:2023/prAA:2025 E

SIST HD 60364-4-43:2023/oprAA:2025
HD 60364-4-43:2023/prAA:2025 (E)
Contents Page
1 European foreword . 3
2 1 Modification to Subclause 431.4, “Protection against overload current” . 4
3 2 Modification to Subclause 431.5, “Protection against short-circuit currents” . 4
4 3 Addition of Annex G, “Position of overcurrent protection devices” . 4
5 Annex G (normative) Position of overcurrent protection devices. 5
6 G.1 General . 5
7 G.2 Positioning of devices for overload protection . 5
8 G.3 Positioning of devices for short-circuit protection . 6
9 4 Addition of Annex ZB, “Special national conditions” and Annex ZC, “A-deviations” . 6
10 Annex ZA (normative)  Special national conditions. 7
11 Annex ZB (informative) A-deviations . 8
SIST HD 60364-4-43:2023/oprAA:2025
HD 60364-4-43:2023/prAA:2025 (E)
12 European foreword
13 This document (HD 60364-4-43:2023/prAA:2025) has been prepared by CLC/TC 64 “Electrical installations
14 and protection against electric shock”.
15 This document is currently submitted to the Enquiry.
16 The following dates are proposed:
• latest date by which the existence of this (doa) dav + 6 months
document has to be announced at national
level
• latest date by which this document has to be (dop) dav + 12 months
implemented at national level by publication of
an identical national standard or by
endorsement
• latest date by which the national standards (dow) dav + 36 months
conflicting with this document have to be (to be confirmed or
withdrawn modified when voting)
SIST HD 60364-4-43:2023/oprAA:2025
HD 60364-4-43:2023/prAA:2025 (E)
17 1 Modification to Subclause 431.4, “Protection against overload current”
18 In 431.4.1, add the following paragraph:
19 “The positioning of overcurrent protective devices for protection against overload currents shall meet the
20 requirements provided in Annex G.”
21 2 Modification to Subclause 431.5, “Protection against short-circuit currents”
22 In 431.5.1, replace Note 1 with the following paragraph:
23 “The positioning of overcurrent protective devices for protection against short-circuit currents shall meet the
24 requirements provided in Annex G.”
25 3 Addition of Annex G, “Position of overcurrent protection devices”
26 Add the following new normative Annex G:
27 “
SIST HD 60364-4-43:2023/oprAA:2025
HD 60364-4-43:2023/prAA:2025 (E)
28 Annex G
29 (normative)
31 Position of overcurrent protection devices
32 G.1 General
33 Devices for overload and/or short-circuit protection shall be installed at the origin of each circuit unless the
34 exceptions of G.2 and/or G.3 are applied.
35 G.2 Positioning of devices for overload protection
36 G.2.1 A device for protection against overload shall be placed at each point where there is a reduction in the
37 value of current-carrying capacity of the conductors except where A.2, G.2.2, G.2.3, or G.2.4 apply. The
38 requirements in G.2.2 to G.2.4 shall not be applied to installations situated in locations presenting a fire risk or
39 risk of explosion.
40 NOTE A reduc
...