MT 2 - TC 64/MT 2

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).

IEC 60364-4-42:2010 applies to electrical installations with regard to measures for the protection of persons, livestock and property against:
- thermal effects, combustion or degradation of materials, and risk of burns caused by electrical equipment,
- flames in case of a fire hazard being propagated from electrical installations to other fire compartments segregated by barriers which are in the vicinity, and
- the impairment of the safe functioning of electrical equipment including safety services.
This third edition cancels and replaces the second edition, published in 2001, and constitutes a technical revision. The main changes with respect to the previous edition are listed below:
- The scope now includes protection against all thermal effects and flames in case of a fire hazard being propagated from electrical installations to other fire compartments segregated by barriers which are in the vicinity.
- Requirements associated with escape routes for evacuation in an emergency have been expanded/modified.
- Requirements associated with the nature of processed or stored materials have been expanded/modified.
- Requirements associated with combustible constructional materials have been expanded/modified.
- Requirements associated with fire propagating structures have been modified slightly.
- New requirements for the selection and erection of installations in locations which might endanger precious goods have been added.
- Protection against overheating now includes space heating appliances.

IEC 60364-7-753:2014 applies to embedded electric heating systems for surface heating. It also applies to electric heating systems for de-icing or frost prevention or similar applications. Both indoor and outdoor systems are covered. Heating systems for industrial and commercial applications complying with relevant parts of IEC 60519, IEC 62395 and IEC 60079 are not covered. This second edition cancels and replaces the first edition published in 2005 and constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
- the title has been changed from "Floor and ceiling heating systems" to "Heating cables and embedded heating systems" to align with the revised scope;
- the scope has been extended and now covers embedded electric heating systems for surface heating, also electric heating systems for de-icing or frost prevention or similar applications, and covers both indoor and outdoor systems. This includes heating systems for: walls, ceiling, floors, roofs, drainpipes, gutters, pipes, stairs, roadways, non-hardened compacted areas (e.g. football fields, lawns);
- for wall heating systems, this standard contains additional requirements (e.g. metal sheath/enclosure/grid) to protect against the effects of overheating caused by a short-circuit between live conductors due to penetration of an embedded heating unit;
- from heating units delivered from the manufacturer without exposed-conductive-parts, this standard requires a metallic mesh grid covering. This has been reduced to 3 mm for wall heating systems;
- this standard now requires that electric heating systems shall be selected and erected so as to avoid any harmful influence between the heating system and any electrical or non-electrical installations envisaged;
- and this standard covers surface temperatures and now refers the reader to the appropriate IEC guide.

IEC/TR 61200-52:2013 is Technical Report which serves as a supplement to IEC 60364-5-52:2009 and explains the rules so as to facilitate the design, selection, erection and maintenance of wiring systems. It follows the numbering of that standard. This technical report is written for everyone concerned with the design, the selection and supply of equipment, as well as the persons who install, maintain and use electrical installations. This second edition cancels and replaces the first edition, published in 1993, and constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
- guidance associated with conduit systems, cable ducting systems, cable trunking systems, cable tray systems and cable ladder systems has been added giving, for example, recommended maximum straight lengths of conduit to ease the installation circuit wiring;
- guidance associated with selection and erection of wiring systems in relation to external influences has been extended to cover impact, and other mechanical stresses;
- guidance for grouping of cables has been added; and
- guidance on maximum temperatures of terminals in normal service conditions has been extended.

IEC 60364-7-713:2013 applies to the wiring system of furniture (and similar fitments) which is connected to the electrical installation. Examples are beds, cupboards, desks and shop display cases, in which electrical equipment such as luminaires, installation couplers according to IEC 61535, socket-outlets, switching devices and wiring systems are installed. This second edition cancels and replaces the first edition, published in 1996, and constitutes a technical revision. This edition includes changes to the scope: the requirements of Part 7-713 now apply to electrical equipment of furniture connected to a supply with a nominal voltage UO not exceeding 230 V and a total load current not exceeding 32 A, including three-phase 32 A supplies. This new edition makes reference to Part 4-41 additional protection and requires that the fixed circuit is protected by an RCD with a rated residual operating current not exceeding 30 mA.

IEC 60364-5-55:2011 The particular requirements apply to extra-low-voltage lighting installations supplied from sources with a maximum rated voltage of 50 V a.c. or 120 V d.c. For the definition of an extra-low voltage lighting system reference should be made to IEC 60598-2-23. This second edition cancels and replaces the first edition, published in 1999, and constitutes a technical revision. The major technical changes with respect to the previous edition are:
- the clause numbering is aligned with the present structure of IEC 60364;
- references to LED modules and their particular installation requirements have been introduced;
- and requirements for cross-sectional area of conductors are modified.

IEC 60364-7-714:2011 applies to the selection and erection of luminaires and lighting installations forming part of an outdoor fixed installation. The origin of the external lighting installation is the supply delivery point of electrical energy by the supply authority or the origin of the circuit supplying the external lighting installation exclusively. The requirements apply to, for example, lighting installations for roads, parks, gardens, places open to the public, sporting areas, illumination of monuments, floodlighting, telephone kiosks, bus shelters, advertising panels, town plans and road signs. The requirements do not apply to:
- public street-lighting installations which are part of the public power grid;
- temporary festoon lighting;
- road traffic signal systems;
- and luminaires which are fixed to the outside of a building and are supplied directly from the internal wiring of that building.
This second edition cancels and replaces the first edition, published in 1996, and constitutes a technical revision. The major technical changes with respect to the previous edition are listed below:
- clause numbering is aligned with present structure of IEC 60364;
- additional protection is required in some cases of equipment incorporating lighting;
- more stringent requirements regarding IP degree of protection;
- introduction of particular requirements for isolation.

IEC 60364-5-55:2011 covers requirements for the selection and erection of low-voltage generating sets and for the selection and erection of luminaires and lighting installations intended to be part of the fixed installation. This second edition cancels and replaces the first edition, published in 2001, its Amendment 1 (2001) and its Amendment 2 (2008). The major technical changes with respect to the previous edition are:
- additional requirements for connection of luminaires to the fixed wiring;
- modification of requirements regarding the fixing of luminaires;
- inclusion of alternative solutions for connecting devices used for through wiring and for connection of luminaires to the supply;
- withdrawal of Clause 556, as IEC 60364-5-56 now covers this matter.

IEC 60364-5-52:2009 deals with the selection and erection of wiring systems. This third edition cancels and replaces the second edition, published in 2001, and constitutes a technical revision. The main changes with respect to the previous edition are as follows:
- Subclause 521.4 introduces minor changes with regard to busbar trunking systems and powertrack systems.
- Subclause 523.6 introduces minor changes with regard to the sizing of cables where harmonic currents are present.
- A new sublause 523.9 concerning single-core cables with a metallic covering has been introduced.
- Clause 525 introduces changes in the maximum value of voltage drop permitted between the origin of the consumer's installation and the equipment which should not be greater than that given in the relevant annex.
- Clause 526 introduces minor changes to electrical connections including additional exceptions for inspection of connections and additional notes.
- Clause 528 introduces additional requirements with regard to proximity of underground power and telecommunication cables.
- Clause 529 introduces minor changes to selection and erection of wiring systems in relation to maintainability, including cleaning. The contents of the corrigendum of February 2011 have been included in this copy.

IEC 60364-4-43:2008 provides requirements for the protection of live conductors from the effects of overcurrents. IEC 60364-4-43:2008 describes how live conductors are protected by one or more devices for the automatic disconnection of the supply in the event of overload (Clause 433) and short-circuit (Clause 434) except in cases where the overcurrent is limited in accordance with Clause 436 or where the conditions described in 433.3 (omission of devices for protection against overload) or 434.3 (omission of devices for protection against short-circuit) are met. Coordination of overload protection and short-circuit protection is also covered (Clause 435). This third edition cancels and replaces the second edition, published in 2001, and constitutes a technical revision. The main changes with respect to the previous edition are:
- Introduction of new informative Annexes B, C and D.
- Information concerning flexible cables added to Scope.
- Requirements added for overload detection for the neutral conductor for harmonic currents.
- Requirement that devices for protection against short-circuit current be capable of making as well as breaking short-circuit current added.
- Information added to clarify protection against overload current.
- Requirements where devices for protection against overload need not be provided expanded.
- Requirements where devices for protection against short-circuit need not be provided expanded.
- Requirements for short-circuit current ratings of busbar trunking systems added. The contents of the corrigendum of October 2008 have been included in this copy.