TC 20 - Electric cables

IEC 60287-2-3:2024 describes a method for calculating the continuous current rating factor for cables of all voltages installed in ventilated tunnels. The method is applicable to any type of cable. The method applies to natural as well as forced ventilation. Longitudinal heat transfer within the cables and the surroundings of the tunnel is assumed to be negligible. All cables are assumed to be identical within the tunnel and it is assumed that the tunnel cross-section does not change with distance along the tunnel.

IEC 60502-2:2014 specifies the construction, dimensions and test requirements of power cables with extruded solid insulation from 6 kV up to 30 kV for fixed installations such as distribution networks or industrial installations. When determining applications, it is recommended that the possible risk of radial water ingress is considered. Cable designs with barriers claimed to prevent longitudinal water penetration and an associated test are included in this part of IEC 60502. Cables for special installation and service conditions are not included, for example cables for overhead networks, the mining industry, nuclear power plants (in and around the containment area) nor for submarine use or shipboard application. This third edition cancels and replaces the second edition, published in 2005, and constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
a) a simplified calculation procedure for the thickness of the lead sheath and the oversheath;
b) a new subclause for the determination of the cable conductor temperature;
c) a modified procedure for the routine voltage test;
d) a new subclause for a routine electrical test on oversheath;
e) modified requirements for the non-metal sheaths including semi-conductive layer;
f) modified tolerances for the bending test cylinder;
g) the inclusion of a 0,1 Hz test after installation.
In addition, the modified structure of the IEC 60811 series has been adopted for this third edition.

IEC 60227-3:2024 details the particular standards for polyvinyl chloride insulated single-core non-sheathed cables for fixed wiring of rated voltages up to and including 450/750 V. This document provides the particular requirements for non-sheathed cables for fixed wiring which apply in addition to the appropriate requirements specified in IEC 60227-1, which apply to all cables. The tests for cables specified in the IEC 60227 series are described in IEC 63294.

IEC 60227-5:2024 details the particular specifications or polyvinyl chloride insulated flexible cables (cords), of rated voltages up to and including 300/500 V. This document provides the particular requirements for flexible cables (cords) which apply in addition to the appropriate requirements specified in IEC 60227-1, which apply to all cables. The tests for cables specified in the IEC 60227 series are described in IEC 63294.

IEC 60227-7:2024 details the particular specifications for polyvinyl chloride insulated, screened and unscreened control cables of rated voltages up to and including 300/500 V. This document provides the particular requirements for screened and unscreened control cables of rated voltages up to and including 300/500 V, which apply in addition to the appropriate requirements specified in IEC 60227-1, which apply to all cables. The tests for cables specified in the IEC 60227 series are described in IEC 63294.

IEC 60227-1:2024 applies to rigid and flexible cables with insulation, and sheath if any, based on polyvinyl chloride, of rated voltages Uo/U up to and including 450/750 V used in power installations of nominal voltage not exceeding 450/750 V AC.
NOTE For some types of flexible cables the term "cord" is used.
The particular types of cables are specified in IEC 60227-3, IEC 60227-4, IEC 60227-5, IEC 60227-6 and IEC 60227-7. The code designations of these types of cables are provided in this document. The test methods specified in this document, IEC 60227-3, IEC 60227-4, IEC 60227-5, IEC 60227-6 and IEC 60227-7 are given in IEC 63294, IEC 60332-1-2 and in the relevant parts of the IEC 60811 series.

IEC 60227-4:2024 details the particular specifications for light polyvinyl chloride sheathed cables of rated voltages of 300/500 V.
This document provides the particular requirements for sheathed cables for fixed wiring which apply in addition to the appropriate requirements specified in IEC 60227-1, which apply to all cables.
The tests for cables specified in the IEC 60227 series are described in IEC 63294.

IEC 60228:2023 specifies the nominal cross-sectional areas, in the range 0,5 mm2 to 3 500 mm2, for conductors in electric power cables and cords of a wide range of types. Requirements for numbers and sizes of wires and resistance values are also included. These conductors include solid, stranded and Milliken, copper, aluminium and aluminium alloy conductors in cables for fixed installations and flexible copper conductors. This document does not apply to conductors for telecommunication purposes. The applicability of this document to a particular type of cable is as specified in the standard for the type of cable. Unless specified otherwise in a particular clause, IEC 60028 ED4 relates to the conductors in the finished cable and not to the conductor as made or supplied for inclusion into a cable. Conductors described in this document are specified in metric sizes. Informative annexes provide supplementary information covering temperature correction factors for resistance measurement (Annex B) and guidance on dimensional limits of circular conductors (Annex C). This document has the status of a horizontal publication in accordance with IEC Guide 108.

IEC 60502-4:2023 specifies the test requirements for type testing of accessories for power cables with rated voltages from 3,6/6 (7,2) kV up to 18/30 (36) kV, complying with IEC 60502‑2 or other relevant cable standards.
Accessories for special applications, such as aerial cables, submarine or ship cables or hazardous situations (explosive environments, fire-resistant cables or seismic conditions), are not included.
It is not necessary to repeat these tests, once successfully completed, unless changes are made in the materials, design or manufacturing process which can affect the performance characteristics.
Test methods are included in IEC 61442.

IEC 60811-201:2012 gives the methods for measuring the insulation thicknesses which apply to the most common types of insulating compounds (cross-linked, PVC, PE, PP, etc.). IEC 60811-201:2012 cancels and replaces 8.1 of IEC 60811-1-1:1993, which is withdrawn. Full details of the replacements are shown in Annex A of IEC 60811-100:2012. There are no technical changes with respect to the previous edition, but see the Foreword to IEC 60811-100:2012.
This publication is to be read in conjunction with IEC 60811-100:2012.

IEC 60811-503:2012 gives the test method for the shrinkage for sheaths. IEC 60811-503:2012 cancels and replaces Clause 11 of IEC 60811-1-3:1993, which is withdrawn. Full details of the replacements are shown in Annex A of IEC 60811-100:2012. There are no specific technical changes with respect to the previous edition, but see the Foreword to IEC 60811-100:2012.
This publication is to be read in conjunction with IEC 60811-100:2012.

IEC 60811-501:2012 gives the procedure for determining the mechanical properties, which typically applies to cross-linked and thermoplastic compounds used for insulating and sheathing materials. IEC 60811-501:2012 cancels and replaces Clause 9 of IEC 60811-1-1:1993, which is withdrawn. Full details of the replacements are shown in Annex A of IEC 60811-100:2012. There is one significant technical change with respect to the previous edition: the requirements for the (minimum) thickness of dumb-bell test pieces have changed. See also the Foreword to IEC 60811-100.
This publication is to be read in conjunction with IEC 60811-100:2012.

IEC 60811-508:2012 gives the procedure for a pressure test at high temperature, which typically applies to thermoplastic compounds used for insulating and sheathing materials. IEC 60811-508:2012 cancels and replaces Clause 8 of IEC 60811-3-1:1985, which is withdrawn. Full details of the replacements are shown in Annex A of IEC 60811-100:2012. Significant technical changes with respect to the previous edition are as follows:
- re-statement of oven characteristics, especially relating to anti-vibration and to temperature control;
- enhanced detail as to the preparations and testing of flat cables;
- enhanced detail as to thickness and dimensional measurements. See also the Foreword to IEC 60811-100:2012.
This publication is to be read in conjunction with IEC 60811-100:2012.

IEC 60811-202:2012 gives the methods for measuring thicknesses of non-metallic sheath which apply to the most common types of sheathing compounds (cross-linked, PVC, PE, PP, etc.). IEC 60811-202:2012 cancels and replaces 8.2 of IEC 60811-1-1:1993, which is withdrawn. Full details of the replacements are shown in Annex A of IEC 60811-100:2012. There are no specific technical changes with respect to the previous edition, but see the Foreword to IEC 60811-100:2012.
This publication is to be read in conjunction with IEC 60811-100:2012.

IEC 61442:2023 specifies the test methods applicable for type testing accessories for power cables with rated voltages from 3,6/6 (7,2) kV up to 18/30 (36) kV. The test methods specified in this document apply to accessories for extruded and paper insulated cables according to IEC 60502-2 and IEC 60055-1 respectively.

IEC 60840:2020 specifies test methods and requirements for power cable systems, cables alone and accessories alone, for fixed installations and for rated voltages above 30 kV (Um = 36 kV) up to and including 150 kV (Um = 170 kV). The requirements apply to single-core cables and to individually screened three-core cables and to their accessories for usual conditions of installation and operation, but not to special cables, such as submarine cables and their accessories, for which modifications to the standard tests or the setup of special test conditions can be necessary. This document does not cover transition joints between cables with extruded insulation and paper insulated cables. This fifth edition cancels and replaces the fourth edition, published in 2011. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
- Gas immersed cable terminations for use at rated voltages above 52 kV are required to be designed, type and routine tested in accordance with IEC 62271-209 in addition to the routine and type tests specified in this document.
- Requirements are introduced for composite outdoor termination insulators.
- The test cylinder diameters specified for the bending test (type and prequalification tests) have been modified in line with IEC TR 61901:2016.
- A low smoke halogen free oversheath material, designated ST12 is introduced.
- Additional tests under fire conditions are introduced: vertical flame spread, smoke density, acidity and conductivity, which shall be applied according to the fire performance declared for the cable.
- A test for water penetration in the conductor is added.
- In addition to tests on the outer protection of joints, type tests on the screen sectionalizing insulation of all accessories have been introduced.
The contents of the corrigendum of February 2021 have been included in this copy.

IEC 60287-2-1:2023 is solely applicable to the conditions of steady-state operation of cables at all alternating voltages, and direct voltages up to 5 kV, buried directly in the ground, in ducts, in troughs or in steel pipes, both with and without partial drying-out of the soil, as well as cables in air. The term "steady state" is intended to mean a continuous constant current (100 % load factor) just sufficient to produce asymptotically the maximum conductor temperature, the surrounding ambient conditions being assumed constant.

IEC 60287-1-3:2023 provides a method for calculating the phase currents and circulating current losses in single-core cables arranged in parallel. The method described in this document can be used for any number of cables per phase in parallel in any physical layout. The phase currents can be calculated for any arrangement of sheath bonding. For the calculation of sheath losses, it is assumed that the sheaths are bonded at both ends. A method for calculating sheath eddy current losses in two circuits in flat formation is given in IEC 60287-1-2.

IEC 60287-1-1:2023 is applicable to the conditions of steady-state operation of cables at all alternating voltages, and direct voltages up to 5 kV, buried directly in the ground, in ducts, troughs or in steel pipes, both with and without partial drying-out of the soil, as well as cables in air. The term "steady state" is intended to mean a continuous constant current (100 % load factor) just sufficient to produce asymptotically the maximum conductor temperature, the surrounding ambient conditions being assumed constant. This document provides formulae for current ratings and losses. The formulae given are essentially literal and designedly leave open the selection of certain important parameters. These can be divided into three groups:
- parameters related to construction of a cable (for example, thermal resistivity of insulating material) for which representative values have been selected based on published work;
- parameters related to the surrounding conditions, which can vary widely, the selection of which depends on the country in which the cables are used or will be used;
- parameters which result from an agreement between manufacturer and user and which involve a margin for security of service (for example, maximum conductor temperature).

IEC 60287-1-2:2023 provides a method for calculating the eddy current losses in the metallic sheaths of single-core cables arranged as a three-phase double circuit in flat formation. The sheaths are bonded at one point or are cross-bonded so that there are no significant sheath circulating currents. Where metallic sheaths are bonded at both ends there are significant circulating currents which result in a lower current-carrying capacity. A method of calculating circulating current losses for double circuits is provided in IEC 60287-1-3.
The method descibed in this document provides coefficients which are applied as corrections to the loss factors for the sheaths of one isolated three-phase circuit. These corrections are negligible for cables where the parameter m is less than approximately 0,1 (m = ω/(Rs · 107)), which corresponds to a sheath longitudinal resistance higher than 314 µΩ/m at 50 Hz.
Consequently, the method is used for most sizes of aluminium-sheathed cables, but is not required for lead-sheathed cables unless they are unusually large.
The coefficients are provided in tabular form and have been computed from fundamental formulae for sheath losses, the evaluation of which calls for expertise in computer programming which will possibly not be readily available in general commercial situations. The development of simplified formulae for some of the tabulated coefficients is under consideration.
Losses for cables in a single circuit is covered in IEC 60287-1-1.

IEC 62067:2022 specifies test methods and requirements for power cable systems, cables with extruded insulation and their accessories for fixed installations, for rated voltages above 150 kV (Um = 170 kV) up to and including 500 kV (Um = 550 kV). The requirements apply to single-core cables and to their accessories for usual conditions of installation and operation, but not to special cables and their accessories, such as submarine cables, for which modifications to the standard tests can be necessary or special test conditions that may need to be devised. This document does not cover transition joints between cables with extruded insulation and paper insulated cables.

IEC 60230:2018 defines the procedure for carrying out withstand lightning and switching impulse tests and withstand superimposed impulse test on cables and their accessories.
This document applies solely to the methods of carrying out the tests as such, independently of the problem of selecting the test levels to be specified. The voltages pertaining to the system on which cables and accessories are to be used are given in IEC 60183 or in the relevant product standard.
This document specifies the following requirements:
- the characteristics and state of the test installation and those parts of the procedure which are common to withstand tests and tests above the withstand level;
- the procedure for carrying out withstand lightning, switching impulse tests and superimposed impulse test;
- the procedure for carrying out tests above the withstand level which is intended for research purposes.
This second edition cancels and replaces the first edition published in 1966. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous edition:
a) the structure of the standard takes into account the current style of IEC standards;
b) this document is no longer a “Recommendation” but an “International Standard”;
c) the test installation is no longer related to gas-pressure and oil-filled cables only;
d) switching-impulse voltage and superimposed impulse voltage tests have been included;
e) for the measuring system the reference to IEC 60060-2 has been added. The reference to the sphere gap method has been moved to Annex B.

IEC 60800:2021 is applicable to, and specifies requirements for resistive heating cables for low temperature applications such as comfort heating and the prevention of ice formation. These heating cables and heating cable sets can comprise either factory assembled or field (work-site) assembled units, and are heating cables assembled in accordance with manufacturer’s instructions. Bare conductors and protected conductors to be supplied at voltages equal to, or less than, 50 V are excluded from the scope of this document.
Typical applications include, but are not limited to:
- surface heating installed in or under surfaces;
- direct and storage heating;
- snow melting and frost protection of roofs, gutters, pipes, etc.
Electrical resistance trace heating systems for industrial and commercial applications are specified in the IEC 62395 series [1] and for explosive atmospheres applications in the IEC/IEEE 60079-30 series [2], as are mineral insulated heating cables. Applications in which the sheath temperature exceeds 100 °C are outside the scope of this document.

IEC 63294:2021 specifies the test methods for electric cables with rated voltages up to and including 450/750 V not included in the IEC 60811 series.

IEC TS 62893-4-2:2021(E) applies to cables for DC charging according to mode 4 of IEC 61851-1. These cables are intended to be used with a thermal management system such as that specified in IEC 61851-23.
Charging cables specified in IEC 62893 (all parts) are intended to be used for electrical appliances of class II equipment.
Maximum conductor operating temperature for the cables in this document is 90 ºC.
The test methods specified are given in IEC 62893-2, IEC 60227-2, IEC 60245-2, IEC 60332 1 2, IEC 62821-1:2015, Annex B and in the relevant parts of IEC 60811.
IEC 62440 is intended to be used as guidance on the safe use of cables in this document together with specific guidance in Clause 6 of this document.

IEC 60502-1:2021 specifies the construction, dimensions and test requirements of power cables with extruded solid insulation for rated AC voltages of 1 kV (Um = 1,2 kV) and 3 kV (Um = 3,6 kV) for fixed installations such as distribution networks or industrial installations. Cables of rated AC voltage 1 kV (Um = 1,2 kV) designed and tested in accordance with this document can also be used, if declared by the manufacturer, in DC distribution systems having their nominal voltage ≤ 750 V DC (with a maximum of 900 V DC) between a live conductor and neutral/earth, or ≤ 1 500 V DC (with a maximum 1 800 V DC) between two live conductors. Applicable core identification for DC systems are considered in accordance with local installation regulations.

IEC 62893-4-1:2020 applies to cables for DC charging according to mode 4 of IEC 61851-1. These cables are not intended to be used with a thermal management system such as that specified in IEC 61851-23.
Charging cables specified in IEC 62893 (all parts) are intended to be used for electrical appliances of class II equipment.
The maximum conductor operating temperature for the cables in this document is 90 °C.
The test methods specified are given in IEC 62893-2, IEC 60245-2, IEC 60332-1-2, IEC 62821‑1:2015, Annex B and in the relevant parts of IEC 60811.
IEC 62440 is intended to be used as guidance on the safe use of cables in this document together with Clause 5 of this document.
This document is to be read in conjunction with IEC 62893-1:2017 and IEC 62893-2:2017.

IEC 63026:2019 specifies test methods and requirements for power cable systems, cables with extruded insulation and their accessories for fixed submarine installations, for rated voltages from 6 kV (Um = 7,2 kV) up to 60 kV (Um = 72,5 kV).
This document includes the electrical tests and the physical tests on materials and components as well as the specific mechanical tests that are applicable to submarine cable systems.
The requirements apply to armoured single-core cables and three-core cables in combination with their accessories, terminations and joints for usual conditions of installation and operation, but not to special cables and their accessories, such as submarine cables for dynamic applications (i.e. for direct connection to a floating structure), for which modifications to the standard tests can be necessary or special test conditions be devised.
This document is applicable to submarine cables installed in permanently submerged conditions with water depths up to 250 m.
This document does not include accessories having a mechanical function only, such as hang-offs or armour clamps.

IEC 62125:2019 provides methodologies addressing environmental evaluation and communication related to cables in normal use.
It includes an environmental checklist for power cables, the method for life cycle assessment (LCA) and a methodology for conductor size optimization.
The results obtained by applying such methodologies can be used for external communication. Environmental communication can also include other topics, such as material declaration.

IEC 63075:2019 specifies test methods and requirements for high-temperature superconducting (HTS) AC power cable systems, cables and their accessories, for fixed installations, for rated voltages from 6 kV (Um = 7,2 kV) up to and including 500 kV (Um = 550 kV).
The requirements apply to single-core, three-core and three-phase concentric cables with cold dielectric and their accessories that are not intended for fault current limitation purposes.
This document does not cover special cables and their accessories, such as fault current limiting cables or submarine cables, for which modifications to the standard tests may be necessary or special test conditions may need to be devised.
This document does not cover test methods and requirements for the cooling system.

IEC 60332-3-21:2018 covers category A F/R for methods of test for the assessment of vertical flame spread of vertically-mounted bunched wires or cables, under defined conditions. This document relates only to power cables of conductor cross-sectional area greater than 35 mm2 installed on the test ladder in a spaced configuration on the front and rear to achieve a nominal total volume of non-metallic material of 7 l/m of test sample. The flame application time is 40 min. This method of mounting is intended for special cable designs used in particular installations when required in the cable specification. Category A F/R is not intended for general use. The test is intended for type approval testing. The requirements for the selection of cables for testing are given in Annex A. The flame spread is measured as the extent of damage of the cable sample. This procedure can be used to demonstrate the cable’s ability to limit flame spread. A recommended performance requirement is given in Annex B.^This second edition cancels and replaces the first edition published in 2000. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
a) adjustments have been made to the title, and elsewhere, to emphasise the standard is applicable to optical fibre cables as well as metallic conductor types;
b) details of the way in which cables are mounted on the ladder have been better defined in order to improve repeatability and reproducibility.
It has the status of a group safety publication in accordance with IEC Guide 104.

IEC 60332-3-23:2018 covers category B for methods of test for the assessment of vertical flame spread of vertically-mounted bunched wires or cables, electrical or optical, under defined conditions.
This document relates to cables installed on the test ladder to achieve a nominal total volume of non-metallic material of 3,5 l/m of test sample. The flame application time is 40 min. The method of mounting uses the front of the standard ladder. The category is intended for general use where medium volumes of non-metallic material are required to be evaluated. The test is intended for type approval testing. The requirements for the selection of cables for testing are given in Annex A. The flame spread is measured as the extent of damage of the cable sample. This procedure can be used to demonstrate the cable’s ability to limit flame spread. A recommended performance requirement is given in Annex B. This second edition cancels and replaces the first edition published in 2000 and Amendment 1:2008. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
a) adjustments have been made to the title, and elsewhere, to emphasise the standard is applicable to optical fibre cables as well as metallic conductor types;
b) details of the way in which cables are mounted on the ladder have been better defined in order to improve repeatability and reproducibility.
It has the status of a group safety publication in accordance with IEC Guide 104.

IEC 60332-3-22:2018 covers category A for methods of test for the assessment of vertical flame spread of vertically mounted bunched wires or cables, electrical or optical, under defined conditions. This document relates to cables installed on the test ladder to achieve a nominal total volume of non-metallic material of 7 l/m of test sample. The flame application time is 40 min. The method of mounting uses the front of the ladder, a standard or wide ladder being used for cables having a conductor cross-section greater than 35 mm2 according to the number of test pieces required, and a standard ladder for conductor cross-sections 35 mm2 and smaller. The category is intended for general use where high volumes of non-metallic material are required to be evaluated. The test is intended for type approval testing. The requirements for the selection of cables for testing are given in Annex A. The flame spread is measured as the extent of damage of the cable sample. This procedure can be used to demonstrate the cable’s ability to limit flame spread. A recommended performance requirement is given in Annex B. This second edition cancels and replaces the first edition published in 2000 and Amendment 1:2008. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
a) adjustments have been made to the title, and elsewhere, to emphasise the standard is applicable to optical fibre cables as well as metallic conductor types;
b) details of the way in which cables are mounted on the ladder have been better defined in order to improve repeatability and reproducibility.
It has the status of a group safety publication in accordance with IEC Guide 104.

IEC 60332-2-25:2018 covers category D for methods of test for the assessment of vertical flame spread of vertically mounted bunched wires or cables, electrical or optical, under defined conditions. This document relates only to small cables of overall diameter 12 mm or smaller and cross-section of 35 mm2 or smaller installed on the test ladder to achieve a nominal total volume of non-metallic material of 0,5 l/m of test sample. The flame application time is 20 min. The method of mounting uses the front of the standard ladder in touching formation only. The category is intended for use with small cables where very low volumes of non-metallic material are required to be evaluated. The test is intended for type approval testing. The requirements for the selection of cables for testing are given in Annex A. The flame spread is measured as the extent of damage of the cable sample. This procedure can be used to demonstrate the cable’s ability to limit flame spread. A recommended performance requirement is given in Annex B. This second edition cancels and replaces the first edition published in 2000 and Amendment 1:2008. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
a) all pre-existing categories of test have been retained and updated;
b) a new category (category D) has been added to cater for testing at very low non-metallic volumes.
It has the status of a group safety publication in accordance with IEC Guide 104.