SC 121B - Low-voltage switchgear and controlgear assemblies

IEC TS 63290:2024 provides additional requirements for assemblies in accordance with the product standards of the IEC 61439 series (Part 2 onwards) that incorporate digital functions and communication, in addition to the conventional electromechanical features of assemblies to reflect what is defined within this document as intelligence. It specifies the definitions, service conditions, constructional requirements, technical characteristics and verification requirements that can be carried out in addition to the IEC 61439 series for intelligent low-voltage switchgear and controlgear assemblies.

IEC 61439-3:2024 defines the specific requirements for distribution boards intended to be operated by ordinary persons (abbreviated DBO throughout this document, see 3.1.101) as follows:
- assemblies intended to be operated by ordinary persons (e.g. switching operations and replacing fuse-links), e.g. in domestic (household) applications;
- assemblies containing outgoing circuits with protective devices intended to be operated by ordinary persons, complying e.g. with IEC 60898-1, the IEC 61008 series, the IEC 61009 series, IEC 62606, IEC 62423 and IEC 60269-3;
- assemblies for applications where the nominal voltage to earth does not exceed 300 V AC (see Table G.1 of IEC 61439-1:2020);
NOTE The voltage limits for DC applications are under consideration.
- assemblies with a rated current (Inc) of the outgoing circuits not exceeding 125 A and a rated current (InA) not exceeding 250 A;
- assemblies intended for use in connection with the generation, transmission, distribution and conversion of electrical energy, and for the control of equipment consuming electrical energy and for associated data processing;
- enclosed, stationary assemblies;
- assemblies for indoor or outdoor use.
This second edition cancels and replaces the first edition published in 2012. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous edition:
a) alignment with the structure of IEC 61439-1:2020;
b) inclusion in the scope of more examples of the type of protection and control devices;
c) deletion of type A and Type B DBOs;
d) addition of a new Annex BB related to DBOs used in a prosumer’s electrical installation (PEI);
e) addition of a new Annex CC related to rated current of a DBO with additional source of supply in parallel/simultaneously with another source that is connected to the DBO e.g. PV.

IEC 61439-4:2023 defines the specific requirements of ACS as follows:
- assemblies for which the rated voltage does not exceed 1 000 V in case of AC or 1 500 V in case of DC;
- assemblies where the nominal primary voltage and the nominal secondary voltage of transformers incorporated in ACS are within the limits specified above;
- assemblies intended for use on construction sites, both indoors and outdoors, i.e. temporary places of work to which the public do not generally have access and where building construction, installation, repairs, alteration or demolition of property (buildings) or civil engineering (public works) or excavation or any other similar operations are carried out;
- transportable (semi-fixed) or mobile ASSEMBLIES with enclosure.
This second edition of IEC 61439-4 cancels and replaces the first edition published in 2012. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
a) alignment with IEC 61439-1:2020 regarding the structure and technical content, as applicable.

IEC 62208:2023 applies to empty enclosures, as provided by the enclosure manufacturer, prior to the incorporation of switchgear and controlgear components by the assembly manufacturer. This document specifies general definitions, classifications, characteristics and test requirements of enclosures to be used as part of switchgear and controlgear assemblies (e.g. in accordance with the product standard in the IEC 61439 series), the rated voltage of which does not exceed 1 000 V AC or 1 500 V DC, and suitable for general use for either indoor or outdoor applications. This third edition cancels and replaces the second edition published in 2011. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
a) consideration of the modifications introduced in IEC 61439-1:2020;
b) alignment of test procedures with the newest relevant standards.

IEC 61439-5:2023 defines the specific requirements for public electricity network distribution assemblies (PENDAs). PENDAs have the following criteria:
- used for the distribution of electrical energy in three phase systems for which the rated voltage does not exceed 1 000 V AC (see Figure 101 for a typical distribution network) and DC systems not exceeding 1 500 V DC;
- stationary;
- open type assemblies are not covered by this document;
- suitable for installation in places where only skilled persons have access for their use, however, outdoor types can be installed in situations that are accessible to ordinary persons
- intended for use in energy distribution in public power grids;
- indoor use: assemblies for installation inside of electric power substations;
- outdoor use: assemblies containing an enclosure suitable for open air installation.
This third edition cancels and replaces the second edition published in 2014. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
a) omission of the requirement to conduct mechanical tests at -25 °C when enclosures are made of a metallic material;
b) addition of assumed loading factors generation supplies and electric vehicle charging applications;
c) additional dielectric tests when a PENDA is used in a distribution substation with separate HV and LV earths;
d) further clarification of representative samples for design verification.

IEC TR 60890:2022 specifies a method of air temperature-rise calculation inside enclosures for low-voltage switchgear and controlgear assemblies or similar products in accordance with their respective standard. The method is primarily applicable to enclosed assemblies or partitioned sections of assemblies without forced ventilation. This third edition cancels and replaces the second edition published in 2014. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
- alignment with IEC 61439-1:2020;
- addition of individual annexes for guidance of technical explanations related to:
--- effect of an uneven power distribution;
--- additional temperature-rise due to solar radiation;
--- effect of different enclosure materials;
--- effect of different natural ventilation management;
--- forced ventilation management;
--- power losses calculation;
--- impact of an adjacent wall can have on the assembly cooling surface(s);
- maximum internal ambient temperature limit into an assembly;
- validity area of the calculation extended from 3 150 A to 3 200 A;
- addition of an algebraic equation to the different curves included in the document.

IEC TR 61439-0:2022 standards for low-voltage switchgear and controlgear assemblies, there are system and application details that are specified by the specifier to enable the manufacturer to produce an assembly that meets the needs and expectations of the specifier.
IEC/TR 61439-0:2022, identifies from the specifier’s perspective those functions and characteristics that are defined when specifying assemblies. It provides:
an explanation of the assembly characteristics and options within the IEC 61439 series;
a guidance on how to select the appropriate options and define characteristics so as to meet specific application needs; and
an assistance in the specification of assemblies.  References within this document to the interface characteristics of an assembly and the requirements with which they will comply assume that the assembly is designed, manufactured, and verified in accordance with the relevant part of the IEC 61439 series.
This third edition cancels and replaces the second edition published in 2013. It constitutes a technical revision.
This third edition includes the following significant technical changes with respect to the previous edition:  
alignment with IEC 61439-1:2020;
addition of new content in Clause 13 regarding current ratings;
addition of a new subclause 12.8.1 detailing the fundamentals of the forms of internal separation;
alignment of Annex B with Annex AA of 61439-2:2020;
removal of the annexes detailing items subject to agreement between specifier and manufacturer for all product parts as not all of them can always be up to date

IEC 61439-7:2022 defines the specific requirements for assemblies for the following applications: marinas, camping sites, market squares and electric vehicle charging stations as follows:
- assemblies for which the rated voltage does not exceed 1 000 V AC or 1 500 V DC;
- assemblies intended for use in connection with the generation, transmission, distribution and conversion of electric energy, and for the control of electric energy consuming equipment;
- assemblies operated by ordinary persons (e.g. to plug and unplug of electrical equipment);
- assemblies intended to be installed and used in market squares, marinas, camping sites and other similar sites accessible to the public including temporary installations;
- assemblies intended for charging stations for electric vehicles (AEVCS) for Mode 3 and Mode 4. They are designed to integrate the functionality and additional requirements for electric vehicle conductive charging systems according to IEC 61851-1:2017.
This second edition cancels and replaces the first edition published in 2018. It constitutes a technical revision. This edition includes the following changes with respect to the previous technical specification:
- a general editorial review and a technical revision.

IEC 61439-2:2020 defines the specific requirements for the power switchgear and controlgear assembly (abbreviated "PSC-assembly" throughout this document see 3.1.101) as follows:
- assemblies for which the rated voltage does not exceed 1 000 V AC or 1 500 V DC;
- assemblies designed for a nominal frequency of the incoming supply or supplies not exceeding 1 000 Hz;
NOTE 1 Frequencies above 1 kHz are considered as high frequencies, see also IEC 60664-1:2007, 5.3.3.2.5 to take into account additional constraints to insulation coordination.
- assemblies intended for indoor and outdoor applications;
- stationary or movable assemblies with or without enclosures;
- assemblies intended for use in connection with the generation, transmission, distribution and conversion of electrical energy, and for the control of equipment consuming electrical energy and for associated data processing;
- assemblies designed for use under special service conditions, for example in ships and in rail vehicles, provided that the other relevant specific requirements are complied with;
NOTE 2 Supplementary requirements for assemblies in ships are covered by IEC 60092-302-2.
This third edition cancels and replaces the second edition published in 2011. It constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
a) addition of Annexes DD, EE and FF for assemblies for use in photovoltaic installation;
b) clarification of the requirements for forms of internal separation and the addition of the requirement, when the form of separation is higher than 1, all parts within the functional unit compartment that remain live when the functional unit is switched off shall be protected to at least IPXXB;
c) alignment with the structure of IEC 61439-1:2020;
d) addition of temperature-rise verification for; (i) temperature-rise verification of assemblies with natural cooling and circuits rated above 1 600 A by a combination of comparison with a reference design and calculation, and; (ii) temperature-rise verification of assemblies with active cooling and rated currents up to 1 600 A;
e) consideration of IP with active cooling.

IEC 61439-1:2020 lays down the general definitions and service conditions, construction requirements, technical characteristics and verification requirements for low-voltage switchgear and controlgear assemblies. NOTE Throughout this document, the term assembly(s) (see 3.1.1) is used for a low-voltage switchgear and controlgear assembly(s). For the purpose of determining assembly conformity, the requirements of the relevant part of the IEC 61439 series, Part 2 onwards, apply together with the cited requirements of this document. For assemblies not covered by Part 3 onward, Part 2 applies. This third edition cancels and replaces the second edition published in 2011. It constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
a) clarification that power electric converter systems, switch mode power supplies, uninterruptable power supplies and adjustable speed power drive systems are tested to their particular products standard, but when they are incorporated in assemblies the incorporation is in accordance with the IEC 61439 series of standards;
b) introduction of a group rated current for circuits within a loaded assembly and the refocusing of temperature-rise verification on this new characteristic;
c) addition of requirements in respect of DC;
d) introduction of the concept of class I and class II assemblies regarding protection against electric shock.
The contents of the corrigendum 1 of December 2021 and corrigendum 2 of September 2023 have been included in this copy.

IEC TS 63107:2020 states requirements for integration and testing of IAMS in low-voltage switchgear and controlgear assemblies – power switchgear and controlgear assemblies according to IEC 61439-1 and IEC 61439-2 (PSC-assemblies) to demonstrate their correct operation.
This document does not address personnel safety or damage to the PSC-assembly. These requirements are dealt with in IEC TR 61641 (see also 10.10.1).

IEC 61439-7:2018 defines the specific requirements of assemblies as follows:
- assemblies for which the rated voltage does not exceed 1 000 V in the case of AC or 1 500 V in the case of DC;
– assemblies intended for use in connection with the generation, transmission, distribution and conversion of electric energy, and for the control of electric energy consuming equipment;
– assemblies operated by ordinary persons (e.g. plug and unplug of electrical equipment);
– assemblies intended to be installed and used in market squares, marinas, campsites and other similar outdoor public sites;
– assemblies intended for charging stations for electric vehicles (AEVCS) for Mode 3 and Mode 4. They are designed to integrate the functionality and additional requirements for electric vehicle conductive charging systems according to IEC 61851-1:2017.
This first edition cancels and replaces the relevant technical specification published in 2014. It constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous technical specification:
a new classification of the stationary ASSEMBLIES in accordance with their mechanical resistance (5.702);
a new Table 702 with the list of tests and relevant severities to which the ASSEMBLIES have to be subjected according to the classification mentioned at point a);
a new Annex (CC) with a new endurance test for the individual switching devices intended to be used in AEVSC, if they have not already been tested against this requirement;
a general editorial review and a technical revision.  The contents of the corrigendum of August 2019 have been included in this copy.

IEC TR 61641:2014 gives guidance on the method of testing of ASSEMBLIES under conditions of arcing in air due to an internal fault. The purpose of this test is to assess the ability of the ASSEMBLY to limit the risk of personal injury, damage of ASSEMBLIES and its suitability for further service as a result of an internal arcing fault. This third edition cancels and replaces the second edition published in 2008. It constitutes a technical revision. This third edition includes the following significant technical changes with respect to the previous edition:
- arcing classes to define the different forms of protection provided against arcing faults; (i) personnel protection, (ii) damage restricted to part of the ASSEMBLY, and (iii) ASSEMBLY suitable for limited further service.;
- two levels of personnel protection afforded by ASSEMBLIES under arcing fault conditions; (i) for ASSEMBLIES installed in areas where access to the ASSEMBLY is restricted to skilled persons, and (ii) for ASSEMBLIES installed in areas where the area is accessible to ordinary persons;
- option of individually insulating all live conductors to make the complete ASSEMBLY an arc ignition protected zone (referred to as an 'arc free zone' in previous editions of the Technical report);
- arc fault protection front, back and sides of an ASSEMBLY as the normal requirement;
- minimum performance requirements for arc ignition protected zone.

IEC 61439-5:2014 defines the specific requirements for public electricity network distribution assemblies (PENDAs). PENDAs have the following criteria:
- used for the distribution of electrical energy in three phase systems for which the rated voltage does not exceed 1 000 V a.c. (see Figure 101 for a typical distribution network);
- open ASSEMBLIES are not covered by this standard;
- suitable for installation in places where only skilled persons have access for their use, however, outdoor types may be installed in situations that are accessible to ordinary persons;
- for indoor or outdoor use.
This second edition cancels and replaces the first edition published in 2010. It constitutes a technical revision. This edition includes the following significant technical changes with respect to the latest edition:
- confirmation that tests carried out on the most onerous PENDA are deemed to verify the performance of similar and less onerous assemblies of the same general construction and rating;
- more precise timing/conditions for impact force withstand tests for PENDAs designed for operation in an arctic climate;
- correction of the direction of the applied force in the static load test.
This publication is to be read in conjunction with IE 61439-1:2011. The contents of the corrigendum of March 2015 have been included in this copy.

IEC TR 60890:2014 specifies a method of temperature-rise verification of low-voltage switchgear and controlgear ASSEMBLIES by calculation. The method is applicable to enclosed ASSEMBLIES or partitioned sections of ASSEMBLIES without forced ventilation. It is not applicable where temperature rise verification to the relevant product standard of the IEC 61439 series has been established. This second edition cancels and replaces the first edition published in 1987 and its Amendment 1:1995. It constitutes a technical revision. This edition includes the following significant technical changes with respect to the last edition:
- alignment with IEC 61439-1:2011;
- revision of Annex B;
- general editorial review.

Specifies the minimum performance requirements, technical characteristics and methods of testing with required test results for VHF radio installations capable of voice communication and digital selective calling as required by the 1988 amendments to the 1974 International Convention for Safety of Life at Sea (SOLAS). Is associated with IEC 60945.

IEC/TR 61439-0:2013(E), which is a technical report identifies, from the user's perspective, those functions and characteristics that should be defined when specifying ASSEMBLIES. It provides:
- an explanation of the ASSEMBLY characteristics and options within the IEC 61439 series;
- a guidance on how to select the appropriate option and to define characteristics so as to meet specific application needs, using a functional approach; and
- an assistance in the specification of ASSEMBLIES. This second edition cancels and replaces the first edition published in 2010. It constitutes a technical revision. This second edition includes the following significant technical changes with respect to the previous edition:
- alignment with IEC 61439-1:2011;
- alignment of Annex B with Annex AA of IEC 61439-2:2011;
- alignment of Table C.1 with Table BB.1 of IEC 61439-2:2011;
- addition of a new Annex D regarding IEC 61439-3;
- addition of a new Annex E regarding IEC 61439-4;
- addition of a new Annex G regarding IEC 61439-6;
- general editorial review. Within the IEC 61439 series of standards for low-voltage switchgear and controlgear assemblies (ASSEMBLIES), there are system and application details that are specified by the user to enable the manufacturer to produce an ASSEMBLY that meets the needs and expectations of the user.

IEC 61439-4:2012 defines the specific requirements of ACS as follows:
- ASSEMBLIES for which the rated voltage does not exceed 1 000 V in case of a.c. or 1 500 V in case of d.c.;
- ASSEMBLIES where the nominal primary voltage and the nominal secondary voltage of transformers incorporated in ACS are within the limits specified above;
- ASSEMBLIES intended for use on construction sites, both indoors and outdoors, i.e. temporary places of work to which the public do not generally have access and where building construction, installation, repairs, alteration or demolition of property (buildings) or civil engineering (public works) or excavation or any other similar operations are carried out;
- transportable (semi-fixed) or mobile ASSEMBLIES with enclosure. The manufacture and/or assembly may be carried out other than by the original manufacturer. This first edition of IEC 61439-4 cancels and replaces the second edition of IEC 60439-4 (2004), and constitutes a technical revision. This edition includes the following significant technical changes with respect to the last edition of IEC 60439-4:
- modification of the title as "Part 4: Particular requirements for assemblies for construction sites (ACS)";
- alignment on IEC 61439-1 regarding the structure and technical content, as applicable;
- to allow comparison with tested ACS.
This publication is to be read in conjunction with IEC 61439-1:2011.

IEC 61439-6:2012 lays down the definitions and states the service conditions, construction requirements, technical characteristics and verification requirements for low voltage BTS (see 3.101) as follows:
- BTS for which the rated voltage does not exceed 1 000 V in case of a.c. or 1 500 V in case of d.c.;
- BTS intended for use in connection with the generation, transmission, distribution and conversion of electric energy, and for the control of electric energy consuming equipment;
- BTS designed for use under special service conditions, for example in ships, in rail vehicles, and for domestic applications (operated by unskilled persons), provided that the relevant specific requirements are complied with;
- BTS designed for electrical equipment of machines. Supplementary requirements for BTS forming part of a machine are covered by the IEC 60204 series. This first edition of IEC 61439-6 cancels and replaces the third edition of IEC 60439-2 (2000) and its Amendment 1 (2005), and constitutes a technical revision. This edition of IEC 61439-6 includes the following significant technical changes with respect to the latest edition of IEC 60439-2:
- alignment on the second edition of IEC 61439-1 (2011) regarding the structure and technical content, as applicable;
- introduction of new verifications, accordingly;
- correction of inconsistencies in resistance, reactance and impedance measurements and calculations;
- numerous editorial improvements.
This publication is to be read in conjunction with IEC 61439-1:2011.

IEC 61439-3:2012 defines the specific requirements for distribution boards intended to be operated by ordinary persons (DBO). DBOs have the following criteria:
- intended to be operated by ordinary persons (e.g. switching operations and replacing fuse-links), e.g. in domestic (household) applications;
- outgoing circuits contain protective devices, intended to be operated by ordinary persons, complying e.g. with IEC 60898-1, IEC 61008, IEC 61009, IEC 62423 and IEC 60269-3;
- rated voltage to earth does not exceed 300 V a.c.;
- rated current (Inc) of the outgoing circuits does not exceed 125 A and the rated current (InA) of the DBO does not exceed 250 A;
- intended for the distribution of electrical energy;
- enclosed, stationary;
- for indoor or outdoor use.
This first edition cancels and replaces the first edition of IEC 60439-3 (1990), Amendment 1 (1993) and Amendment 2 (2001). It constitutes a technical revision. This edition includes the following significant technical changes with respect to IEC 60439-3 (including the amendments):
- alignment with IEC 61439-1:2011.
This publication is to be read in conjunction with IEC 61439-1:2011. The contents of the corrigenda of September 2013 and March 2019 have been included in this copy.

IEC 61439-1:2011 lays down the definitions and states the service conditions, construction requirements, technical characteristics and verification requirements for low-voltage switchgear and controlgear assemblies. This standard cannot be used alone to specify an ASSEMBLY or used for a purpose of determining conformity. ASSEMBLIES shall comply with the relevant part of the IEC 61439 series; Parts 2 onwards. This standard applies to low-voltage switchgear and controlgear assemblies (ASSEMBLIES) only when required by the relevant ASSEMBLY standard as follows:
- ASSEMBLIES for which the rated voltage does not exceed 1 000 V in case of a.c. or 1 500 V in case of d.c.;
- stationary or movable ASSEMBLIES with or without enclosure;
- ASSEMBLIES intended for use in connection with the generation, transmission, distribution and conversion of electric energy, and for the control of electric energy consuming equipment;
- ASSEMBLIES designed for use under special service conditions, for example in ships and in rail vehicles provided that the other relevant specific requirements are complied with;
- ASSEMBLIES designed for electrical equipment of machines provided that the other relevant specific requirements are complied with. This second edition cancels and replaces the first edition published in 2009. It constitutes a technical revision. This second edition includes the following significant technical changes with respect to the last edition of IEC 61439-1:
- revision of service conditions in Clause 7;
- numerous changes regarding verification methods in Clause 10;
- modification of routine verification in respect of clearances and creepage distances (see 11.3);
- adaption of the tables in Annex C and Annex D to the revised requirements and verification methods;
- revision of the EMC requirements in Annex J;
- shifting of tables from Annex H to new Annex N;
- new Annex O with guidance on temperature rise verification;
- new Annex P with a verification method for short-circuit withstand strength (integration of the content of IEC/TR 61117);
- update of normative references;
- general editorial review.

IEC 62208:2011 applies to empty enclosures, prior to the incorporation of switchgear and controlgear components by the user, as supplied by the enclosure manufacturer. This standard specifies general definitions, classifications, characteristics and test requirements of enclosures to be used as part of switchgear and controlgear assemblies (e.g. in accordance with the IEC 61439 series), the rated voltage of which does not exceed 1 000 V a.c. or 1 500 V d.c., and suitable for general use for either indoor or outdoor applications. This second edition cancels and replaces the first edition published in 2002. This edition constitutes a technical revision and includes the following significant technical changes with respect to the last edition:
- consideration of the restructured series of standards IEC 61439;
- alignment of test procedures with the newest relevant standards.

IEC 61439-2:2011 defines the specific requirements of power switchgear and controlgear assemblies (PSC-ASSEMBLIES) as follows:
- ASSEMBLIES for which the rated voltage does not exceed 1 000 V in case of a.c. or 1 500 V in case of d.c.;
- stationary or movable ASSEMBLIES with or without enclosure;
- ASSEMBLIES intended for use in connection with the generation, transmission, distribution and conversion of electric energy, and for the control of electric energy consuming equipment;
- ASSEMBLIES designed for use under special service conditions, for example in ships and in rail vehicles provided that the other relevant specific requirements are complied with;
- ASSEMBLIES designed for electrical equipment of machines.
Supplementary requirements for ASSEMBLIES forming part of a machine are covered by the IEC 60204 series. This second edition cancels and replaces the first edition published in 2009. It constitutes a technical revision. This second edition includes the following significant technical changes with respect to the last edition of IEC 61439-2:
- clarification of the scope;
- revision of requirements for withdrawable and removable parts;
- revision of mechanical impact test (10.2.6);
- extension of Table 101;
- review of Table BB.1 to reflect modified requirements and verifications;
- general editorial review.
This publication is to be read in conjunction with IEC 61439-1:2009.

IEC 61439-5:2010 gives specific requirements for public electricity network distribution assemblies (PENDAs), which are stationary assemblies verified by verification tests, as defined in this standard. These ASSEMBLIES are used for the distribution of electrical energy in three-phase systems (see Figure 101 for a typical distribution network). Open type ASSEMBLIES are not covered by this standard. This first edition of IEC 61439-5 cancels and replaces the second edition of IEC 60439-5 (2006), and constitutes a technical revision. This edition of IEC 61439-5 includes the following significant technical changes with respect to the latest edition of IEC 60439-5:
- alignment on IEC 61439-1 regarding the structure and technical content, as applicable;
- introduction of new verifications, accordingly;
- harmonisation of the requirements of substation cable distribution boards and cable distribution cabinets, thereby eliminating the need to identify and define two catagories of assembly;
- simpler standard as a result of a reduction in the number of assembly types defined and the acronyms used to identify the different assemblies.
This publication is to be read in conjunction with IEC 61439-1:2009.

IEC/TR 61439-0:2010(E) Within the IEC 61439 series of standards for low-voltage switchgear and controlgear assemblies (ASSEMBLIES), there are system and application details that need to be specified by the user to enable the manufacturer to produce an ASSEMBLY that meets the needs and expectations of the user. IEC/TR 61439-0:2010(E) identifies, from the user's perspective, those functions and characteristics that should be defined when specifying ASSEMBLIES. It provides:
- an explanation of the ASSEMBLY characteristics and options within the IEC 61439 series;
- a guidance on how to select the appropriate option and to define characteristics so as to meet specific application needs, using a functional approach; and
- an assistance in the specification of ASSEMBLIES.

IEC 61439-1:2009 lays down the definitions and states the service conditions, construction requirements, technical characteristics and verification requirements for low-voltage switchgear and controlgear assemblies. This standard applies to low-voltage switchgear and controlgear assemblies (ASSEMBLIES) only when required by the relevant ASSEMBLY standard. This first edition of IEC 61439-1 standard cancels and replaces the fourth edition of IEC 60439-1:1999. Significant technical changes with respect to the last edition of IEC 60439-1. IEC 61439-1 is a pure "general rules" standard to be referred to by subsidiary product parts of the IEC 61439 series; the product standard replacing IEC 60439-1 is IEC 61439-2; the discrimination between type-tested assemblies (TTA) and partially type-tested assemblies (PTTA) is eliminated by the verification approach; three different but equivalent types of verification of requirements are introduced: verification by testing, verification by calculation/measurement, or verification by satisfying design rules; the requirements regarding temperature rise have been clarified; the rated diversity factor (RDF) is covered in more detail; requirements from the standard for empty enclosures for assemblies (IEC 62208) have been incorporated; the whole structure of the standard is aligned with its new function as "general rules" standard. However, when a dated reference to IEC 60439-1 is made in another Part of the IEC 60439 series of assembly standards not yet transferred into the new IEC 61439 series, the superseded IEC 60439-1 still applies.

IEC 61439-2:2009 standard defines the specific requirements of power switchgear and controlgear assemblies (PSC-ASSEMBLIES), the rated voltage of which does not exceed 1000 V a.c. or 1500 V d.c. This standard is to be read in conjunction with IEC 61439-1.
This publication is to be read in conjunction with IEC 61439-1:2009.

This technical report applies to enclosed low-voltage switchgear and controlgear assemblies hereafter called ASSEMBLIES manufactured according to IEC 60439-1. This second edition cancels and replaces the first edition (1996) and constitutes a technical revision. The main change introduced in this new edition is the following: the concept of ASSEMBLY protection under arcing conditions has been introduced.

Applies to empty enclosures, prior to the incorporation of switchgear and controlgear components by the user, as supplied by the enclosure manufacturer. This standard specifies definitions, classifications, characteristics and test requirements of enclosures to be used as part of switchgear and controlgear assemblies in accordance with the IEC 60439 series, the rated voltage of which does not exceed 1 000 V a.c. at frequencies not exceeding 1 000 Hz, or 1 500 V d.c. and suitable for general use for either indoor or outdoor applications. This standard does not apply to enclosures, which are covered by other specific products standards (e.g. IEC 60670). Compliance with the safety requirements of the applicable product standard is the responsibility of the final assembly manufacturer.

This standard applies to type-tested assemblies (TTA) intended for use on construction sites, i.e. temporary places of work to which the public do not generally have access and where building construction, installation, repairs, alteration or demolition of property (buildings) or civil engineering (public works) or excavation or any other similar operations are carried out. These assemblies may be transportable (semi-fixed) or mobile.

Gives supplementary requirements for cable distribution cabinets (CDC), which are stationary, type-tested assemblies (TTA) for outdoor installation in places which are exposed to the public, but where only skilled persons have access to their use. They are safe for use in public three-phase systems

IEC TS 61439-7:2014-02(en-fr) defines the specific requirements of ASSEMBLIES as follows:
- ASSEMBLIES for which the rated voltage does not exceed 1 000 V in case of a.c. or 1 500 V in case of d.c;
- stationary or movable ASSEMBLIES with enclosure;
- ASSEMBLIES intended for use in connection with the generation, transmission, distribution and conversion of electric energy, and for the control of electric energy consuming equipment;
- ASSEMBLIES operated by ordinary persons;
- ASSEMBLIES intended to be installed and used in marinas, camping sites, market squares and other similar external public sites or similar sites;
- ASSEMBLIES intended for charging stations for electric vehicles.
This publication is to be read in conjunction with IEC 61439-1:2011

This standard gives supplementary requirements for substation cable distribution boards (SCDBs) and cable distribution cabinets (CDCs), which are stationary, type-tested assemblies (TTA). They are used for the distribution of electrical energy in three-phase systems. Open-type ASSEMBLY are not covered by this standard.

Applies to busbar trunking systems intended to supply luminaires through tap-off units but does not apply to supply track systems in accordance with IEC Publication 570.

Applies to type-tested ASSEMBLIES (TTA) intended for use on construction sites, i.e. temporary places of work to which the public do not generally have access and where building construction, installation, repairs, alteration or demolition of property (buildings) or civil engineering (public works) or excavation or any other similar operations are carried out. These ASSEMBLIES may be transportable (semi-fixed) or mobile. This standard does not apply to ASSEMBLIES for use in the administrative centres of construction sites (offices, cloakrooms, ASSEMBLY rooms, canteens, restaurants, dormitories, toilets, etc.). The nominal primary voltage and the nominal secondary voltage of transformers incorporated in ACS shall be within the limits specified in IEC 60439-1. Requirements for electrical protection provided by equipment manufactured according to this International Standard shall comply with the requirements given in IEC 60364-7-704. NOTE: This standard may be used as a guide to partially type-tested ASSEMBLIES (PTTA) constructed according to agreement between manufacturer and user taking into account the nature of supply and/or distribution network and relevant installation requirements. The following major changes with respect to edition 1 (including amendments 1 and 2) have been incorporated: - introduction of the definition for "rated current of ACS"; - replacement of classification based on the rated current of ACS by classification based on the function as assigned by the manufacturer; - amended requirements for the protection of socket-outlets with reference to the more comprehensive requirements of IEC 60364-7-704; - introduction of common requirements for all types of ACS.

Applies to low-voltage switchgear and controlgear assemblies (type-tested assemblies (TTA) and partially type-tested assemblies (PTTA)), the rated voltage of which does not exceed 1 000 V a.c. at frequencies not exceeding 1 000 Hz, or 1 500 V d.c.

The contents of the corrigendum of November 2004 have been included in this copy.

This standard gives supplementary requirements for enclosed distribution boards (DBU), which are stationary, type-tested assemblies (TTA) for indoor use, containing protective devices and intended for use either in domestic (household) applications or in other places where unskilled persons have access for their use.