SC 17C - Assemblies

IEC 62271-202:2022 specifies the service conditions, rated characteristics, general structural requirements and test methods of enclosed high-voltage prefabricated substations. These prefabricated substations are cable-connected to AC high-voltage networks with an operating voltage up to and including 52 kV and power frequencies up to and including 60 Hz. They can be manually operated from inside (walk-in type) or from outside (non-walk-in type). They are designed for outdoor installation at locations with public accessibility and where protection of personnel is provided.
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:
the whole document contents and structure are reviewed with due consideration of IEC 62271-1:2017;
modification of the title and scope to include high-voltage switchgear prefabricated substations;
inclusion of CEADS as a possible component of MV/LV prefabricated substation;
in 7.2.101, the possible influence of surrounding elements on the dielectric performance of high-voltage components as high-voltage switchgear and controlgear and high-voltage interconnections non-metal-enclosed or without earthed screen are now considered;
new informative Annex G with testing procedure to evaluate the impact of solar radiation in temperatures inside the enclosure and how to apply it;
new informative Annex H for appropriate consideration of installation conditions of electronic equipment;
the rated power of a prefabricated substation is now defined as a three-parameter rated value. See 5.101.1;
minimum dimensions for access doors to the prefabricated substation in 6.104.4 and for free height of operation aisle in 6.105.3 have been introduced;
continuous current (temperature rise) test methods have been revised/clarified where necessary;
Figure D.1, which shows the mineral-oil-immersed power transformer load factor inside the enclosure, has been corrected.

IEC 62271-209:2019 is available as IEC 62271-209:2019 RLV which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.
IEC 62271-209:2019 covers the connection assembly of fluid-filled and extruded cables to gas-insulated metal enclosed switchgear (GIS), in single- or three-phase arrangements where the cable terminations are fluid-filled or dry-type and there is a separating insulating barrier between the cable insulation and the gas insulation of the switchgear. This second edition cancels and replaces the first edition published in 2007. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
a) New numbering in accordance with ISO/IEC directives, Part 2 (2016) and to IEC 62271‑1:2017;
b) Clause 3: addition of a definition for plug-in cable termination, filling pressure and minimum function pressure for insulation;
c) Clause 7: An additional dielectric type test for plug-in cable termination was added; also a pressure type test as well as a leak rate test on the insulator of a cable termination was implemented;
d) Clause 12: New clause about safety practices;
e) Clause 13: New clause about influence of the product on the environment;
f) New informative Annex A: Mechanical forces applied on the flange of the cable connection enclosure.

IEC 62271-212:2022 is available as IEC 62271-212:2022 RLV which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.
IEC 62271-212;2022 specifies the service conditions, rated characteristics, general structural requirements and test methods of the assemblies of the main electrical functional units of a high-voltage transformer substation, duly interconnected, for AC voltages up to and including 52 kV on the high-voltage side and service frequency 50 Hz or 60 Hz. The CEADS is cable‑connected to the high-voltage network for indoor and outdoor applications of restricted access. This second edition cancels and replaces the first edition published in 2016. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
- clause numbering aligned with IEC 62271-1:2017,
- rewording of title and scope of the document,
- implement changes on internal arc definition and testing following the evolution of prefabricated substation concept according to IEC 62271-202,
- general review of main test procedures such as temperature rise or dielectric test on interconnections, considering control equipment, communication, smart grid devices and integration of components,
- general review of installation, operation, safety and maintenance requirements.

IEC 62271-202:2022 specifies the service conditions, rated characteristics, general structural requirements and test methods of enclosed high-voltage prefabricated substations. These prefabricated substations are cable-connected to AC high-voltage networks with an operating voltage up to and including 52 kV and power frequencies up to and including 60 Hz. They can be manually operated from inside (walk-in type) or from outside (non-walk-in type). They are designed for outdoor installation at locations with public accessibility and where protection of personnel is provided.
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:
the whole document contents and structure are reviewed with due consideration of IEC 62271-1:2017;
modification of the title and scope to include high-voltage switchgear prefabricated substations;
inclusion of CEADS as a possible component of MV/LV prefabricated substation;
in 7.2.101, the possible influence of surrounding elements on the dielectric performance of high-voltage components as high-voltage switchgear and controlgear and high-voltage interconnections non-metal-enclosed or without earthed screen are now considered;
new informative Annex G with testing procedure to evaluate the impact of solar radiation in temperatures inside the enclosure and how to apply it;
new informative Annex H for appropriate consideration of installation conditions of electronic equipment;
the rated power of a prefabricated substation is now defined as a three-parameter rated value. See 5.101.1;
minimum dimensions for access doors to the prefabricated substation in 6.104.4 and for free height of operation aisle in 6.105.3 have been introduced;
continuous current (temperature rise) test methods have been revised/clarified where necessary;
Figure D.1, which shows the mineral-oil-immersed power transformer load factor inside the enclosure, has been corrected.
The contents of the corrigendum of August 2023 have been included in this copy.

IEC 62271-204:2022 is available as IEC 62271-204:2022 RLV which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.IEC 62271-204:2022 applies to rigid HV gas‑insulated transmission lines (GIL) in which the insulation is obtained, at least partly, by an insulating gas or gas mixture other than air at atmos­pheric pressure, for alternating current of rated voltages above 52 kV, and for service frequencies up to and including 60 Hz. This second edition cancels and replaces the first edition published in 2011. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
- update to be in line with IEC 62271-1:2017 and alignment of the voltage ratings and the test voltages.
- addition of new information for welds on pressurized parts and gas tightness.

IEC 62271-203:2022 specifies requirements for gas-insulated metal-enclosed switchgear in which the insulation is obtained, at least partly, by an insulating gas or gas mixture other than air at atmospheric pressure, for alternating current of rated voltages above 52 kV, for indoor and outdoor installation, and for service frequencies up to and including 60 Hz. 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:
- the document has been aligned with IEC 62271-1:2017;
- beside SF6 also alternative gases have been implemented where needed;
- the terms and definitions have been updated and terms not used have been removed;
- Subclause 6.16 “Gas and vacuum tightness” has been updated;
- Subclause 6.16.3 “Closed pressure systems”: Two classes of gas has been introduced:
- GWP ≤ 1 000
- GWP > 1 000
and the tightness requirements for type tests for gasses with GWP > 1 000 has been reduced from 0,5 % to 0,1 % per year per gas compartment;
- Subclause 6.108 “Interfaces”: Typical maximum pressures in service for interfaces connected to GIS have been defined;
- Subclauses 7.102 through 7.108 have been restructured;
- Subclause 7.107 “Corrosion test on earthing connections” has been updated;
- Subclause 7.108 “Corrosion tests on sealing systems of enclosures and auxiliary equipment” has been updated;
- Annex F ‘Service Continuity’ has been modified and aligned with the recommendations of CIGRE WG B3.51.

IEC 62271-215:2021 is applicable to phase comparators designed to be plugged into the testing points of a voltage detecting and indicating system (VDIS) according to IEC 62271-213, to give an indication of the result of a phase comparison.
The main usage is to provide a clear evidence of the phase relationship between two energized parts of a high-voltage network, at the same nominal voltage and frequency before coupling them.
This first edition cancels and replaces the first edition of IEC 61243-5 published in 1997 and the first edition of IEC 62271-206 published in 2011. This edition constitutes a merging of the content of IEC 61243-5 and IEC 62271-206.
This edition includes the following significant technical changes with respect to the previous editions of IEC 61243-5 and IEC 62271-206:
the document does not include the specific phase comparators (SPCs) as defined in IEC 61243-5, which was specific to manufacturers, and takes back the technical principles of the universal phase comparator (UPC) for VDIS of all manufacturers;
the phase comparator for sequential connected operation is introduced to facilitate the operation of phase comparation of large MV panels.

IEC 62271-213:2021 is applicable to the voltage detecting and indicating system (VDIS) to be installed on indoor and outdoor high-voltage equipment.
The VDIS as defined by this document includes a coupling system per phase (capacitive, resistive coupling or other technology) to connect to live parts (main circuit).
This first edition cancels and replaces the first edition of IEC 61243-5 published in1997 and the first edition of IEC 62271-206 published in 2011. This edition constitutes a merging of the content of IEC 61243-5 and IEC 62271-206.
This edition includes the following significant technical changes with respect to the previous editions of IEC 61243-5 and IEC 62271-206:
a) an optional output signal is defined to be used for multipurpose use cases;
b) only one interface is defined for voltage detecting and indicating system (VDIS);
c) the measurement of the current carrying capacity of the voltage limiting element is considered as inaccurate and is not considered in this document. The experience shows that a probability of the failure of the coupling element is negligible.

IEC 62271-200:2021 is applicable to prefabricated metal‑enclosed switchgear and controlgear assemblies designed for:
– alternating current;
– rated voltages above 1 kV and up to and including 52 kV;
– service frequencies up to and including 60 Hz;
– indoor and outdoor installation.
The assembly can include air-insulated and/or fluid-filled compartments.
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) clause numbering aligned with IEC 62271‑1:2017, including the adoption of the subclause names of Clause 3;
b) in Clause 3 specific definitions are added for "in service", "normal operating condition" and "normal use";
c) internal arc testing on pole-mounted switchgear is taken out of this document, as it is now covered by the specific standard IEC 62271‑214:2019;
d) a more precise description of earthing circuit is given with the inclusion of ratings and test requirements;
e) number of mechanical tests on interlocks is reduced for type testing; a more precise description of forces to apply during type testing is given (refer to 7.102);
f) resistance measuring on main circuit is only needed before continuous current tests (as reference for routine tests) and no longer needed after this continuous current test. Rationale for this deletion is that this measured resistance does not mean anything; as the temperature rise test was just finished, a new temperature rise test will not give new information;
g) IEC 62271-100:2021, IEC 62271-103:2021, IEC 62271-105:2021 and IEC 62271-106:2021 are referred to in the document;
h) IEC 62271‑107:2019 and IEC IEEE 62271‑37‑013:2015 are also considered in 7.101.2;
i) a more precise description of LSC category is given with the inclusion of an explanatory flowchart (Annex D);
j) examples not covered by the IAC test are transferred from Clause 6 to 9.103;
k) the term "assembly" is defined in Clause 3 and used as synonym for "metal-enclosed switchgear and controlgear" in this document;
l) "metallic" is replaced by "metal" where applicable;
m) 6.105 is now covered by 7.7;
n) a 1 s rule was introduced for Criterion 4 during IAC tests regarding hot gases versus glowing particles as cause of ignition;
o) a more precise description of internal arc tests for switchgear with protrusions is given in Annex A.

IEC TR 62271-312:2021(E) refers to high-voltage / low-voltage prefabricated substations (hereinafter prefabricated substations) as specified in IEC 62271-202:2014.
This document, among other options as agreed between manufacturer and user, can be used for the transferability of type tests performed on one or more prefabricated substations with a defined set of ratings and arrangement of components to another prefabricated substation with a different set of ratings or different arrangement of components. It supports the selection of appropriate representative test objects for that purpose in order to optimize the type testing procedure for a consistent conformity assessment.
This document utilises a combination of sound technical and physical principles, manufacturer and user experience and mutually agreed upon methods of calculation to establish pragmatic guidance for the transferability of type test results, covering various design and rating aspects.

IEC 62271-214:2019 specifies requirements for internal arc classification of metal-enclosed pole-mounted switchgear installations used for alternating current with rated voltages above 1 kV and up to and including 52 kV with service frequencies up to and including 60 Hz. This document is applicable to three-phase, two-phase and single phase equipment. Enclosures may include fixed and removable components and may be filled with fluid (liquid or gas) to provide insulation.

IEC TS 62271-304:2019 applies to indoor enclosed switchgear and controlgear complying with IEC 62271-200 and IEC 62271-201, intended to be used in special service conditions with respect to condensation and pollution deviating from the normal service conditions specified in IEC 62271-1.
The test detailed in this document has been designed primarily to classify the electrical insulation performance of equipment having high-voltage electrical insulation exposed to indoor service conditions, mainly in presence of condensation. The assessment of mechanical components, such as mechanisms, interlocks and enclosure is also considered.
This second edition cancels and replaces the first 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 description of the several service conditions under condensation and pollution;
b) the classification of enclosed switchgear and controlgear, according to the testing procedure does not cover polluted service conditions PL and PH;
c) a wider description in Annex B of typical indoor environments based on ISO/IEC standards;
d) a new Annex C giving guidance on precautions to improve indoor operating conditions;
e) a new Annex D dedicated to the optional items such as records of mechanical characteristics;
f) a new Annex E, giving additional combinations of environments with condensation and pollution, as well as a proposal of testing procedure of ageing test, is provided to create experience on correlation between ageing effects in laboratory and ageing effects at site conditions.

IEC 62271-212:2016 specifies the service conditions, rated characteristics, general structural requirements and test methods of the assemblies of the main electrical functional units of a high-voltage/low-voltage distribution substation, duly interconnected, for alternating current of rated operating voltages above 1 kV and up to and including 52 kV on the high-voltage side, service frequency 50 Hz or 60 Hz. This assembly is to be cable-connected to the network, and intended for installation within an indoor or outdoor closed electrical operating area.
This publication is to be read in conjunction with IEC 62271-1:2007

IEC TR 62271-307:2015 refers to prefabricated metal-enclosed and solid-insulation enclosed (both hereinafter called enclosed) switchgear and controlgear assemblies for alternating current of rated voltages above 1 kV and up to and including 52 kV as specified in IEC 62271-200 and IEC 62271-201, and to other equipment included in the same enclosure with any possible mutual influence.
This publication is to be read in conjunction with IEC 62271-200:2011 and IEC 62271-201:2014.

IEC 62271-3:2015 is applicable to high-voltage switchgear and controlgear for all rated voltage levels above 1 kV and assemblies thereof and specifies equipment for digital communication with other parts of the power utility automation and its impact on testing. This equipment for digital communication, replacing metal parallel wiring, can be integrated into the high-voltage switchgear, controlgear, and assemblies thereof, or can be external equipment in order to provide compliance for existing switchgear and controlgear and assemblies thereof with the standards of the IEC 61850 series. This second edition cancels and replaces the first edition published in 2006. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
a) an update to the latest edition(s) of IEC 61850 series; (e.g. Annex B "LNs for sensors and monitoring" of edition 1 has been deleted since these LNs are now covered by standard IEC 61850-7-4:2010)
b) an update of normative references;
c) the minimum voltage range this standard refers to, was changed from 72,5 kV to above 1 kV;
d) the description of performance tests and conformance tests became more specific;
e) the new - informative - Annex C gives an example for performance type testing;
f) 6.2.3 "transmission systems" as well as appropriate subclauses have been superseded by standard IEC TR 61850-90-4:2013;
g) fibre optical connector type LC becomes only recommended type of fibre optic connector in accordance with IEC TR 61850-90-4:2013;
h) electronic nameplates have been redefined as extension of LN XCBR and LN XSWI with data objects, reflecting required additional name plate information.

IEC 62271-211:2014 is applicable to single and three phase direct connections between gas-insulated metal-enclosed switchgear (GIS) for rated voltages above 52 kV and transformer arrangements to establish electrical and mechanical interchange ability and to determine the limits of supply of for the transformer connection. This first edition cancels and replaces the first edition of IEC TR 61639:1996 and constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
a) transfer from technical report to international standard;
b) the minimum voltage rating was changed from 72,5 kV to above 52 kV;
c) update of normative references;
d) definition of insulated junction including limit of supply;
e) definition of dielectric test of gas-insulated metal-enclosed switchgear for transformer connection in a three phase enclosure;
f) addition of interface tolerances at transformer side;
g) addition of transformer tolerances in service;
h) addition of exceptional loads for bushings and flanges;
i) consideration of oil- and gas-insulated transformers;
j) inclusion of three-phase enclosed direct connections. The contents of the corrigendum 1 of August 2015 and corrigendum 2 of August 2017 have been included in this copy.

IEC 62271-202:2014 specifies the service conditions, rated characteristics, general structural requirements and test methods of high voltage/low voltage or low voltage/high voltage prefabricated substations, which are cable-connected, to be operated from inside (walk-in type) or outside (non-walk-in type) for alternating current of rated voltages above 1 kV and up to and including 52 kV on the high voltage side, and for one or more transformers for service frequencies up to and including 60 Hz for outdoor installation at locations with public accessibility and where protection of personnel is provided. This second edition cancels and replaces the first edition published in 2006. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
a) regarding temperature-rise test an alternative method for liquid filled transformers is (re)introduced and the temperature-rise test method for dry-type transformers is specified more precisely;
b) testing procedure for short time and peak withstand current tests are specified more precisely;
c) assessment of electromagnetic fields is considered including a type test (optional) according IEC/TR 62271-208:2009;
d) influence of the product on the environment is considered (Clause 12);
e) internal arc test requirements have been adapted to IEC 62271-200:2011 and requirements for the assessment of pressure relief volumes below the floor / ground has been assigned;
f) the method for defining the load factor in an enclosure for liquid filled transformers is extended with different temperature rises for the transformer outside the enclosure (Annex DD);
g) for the calculation of the load factor of dry-type transformers in an enclosure the insulation systems according to IEC 60076-1:2011, Tables B.1 and B.2 are worked out in detail.
This publication is to be read in conjunction with IEC 62271-201:2007. The contents of the corrigendum of April 2015 have been included in this copy.

IEC 62271-201:2014 specifies requirements for prefabricated solid-insulation enclosed switchgear and controlgear for alternating current of rated voltages above 1 kV and up to and including 52 kV for indoor installation and for service frequencies up to and including 60 Hz. This second edition cancels and replaces the first edition, published in 2006. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
a) apart from updating with the second edition of IEC 62271-200 (issued in 2011), definitions, classifications and testing procedures have been specified more precisely;
b) access to the solid-insulation enclosed switchgear and controlgear is now restricted to authorized personnel only. This implies that "accessibility class B" (public access) has been deleted throughout the document;
c) the term "protection category" has been introduced to replace the term "protection grade" (PA, PB1 and PB2).
This publication is to be read in conjunction with IEC 62271-201:2007.

IEC 62271-207:2012 applies to gas-insulated switchgear assemblies for alternating current of rated voltages above 52 kV for indoor and outdoor installations, including their supporting structure. This second edition of IEC 62271-207 cancels and replaces the first edition published in 2007. It constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
- modification of the minimum voltage rating from 72,5 kV to above 52 kV;
- harmonisation of qualification procedures for GIS with IEEE 693:2005 Annex A and P by modifying the response spectra;
- modification of the test procedures;
- addition of criteria of allowed stresses;
- addition of dynamic analysis CQC. The contents of the corrigendum of January 2013 have been included in this copy.

IEC 62271-200:2011 specifies requirements for prefabricated metal enclosed switchgear and controlgear for alternating current of rated voltages above 1 kV and up to and including 52 kV for indoor and outdoor installation, and for service frequencies up to and including 60 Hz. Enclosures may include fixed and removable components and may be filled with fluid (liquid or gas) to provide insulation. This second edition cancels and replaces the first edition, published in 2003. It is a technical revision. This second edition of IEC 62271-200 has been further updated and improved to the experience gained with the first edition of IEC 62271-200. As maintenance result, this second edition of IEC 62271-200 introduces the following significant changes:
- definitions, classifications and testing procedures are specified more precisely;
- categories LSC2A and LSC2B have been clarified and LSC2 has been assigned a separate definition;
- specific ratings related to fault level to earth (4.5 to 4.7) are introduced;
- solid insulated high-voltage parts are no longer considered as compartments on their own;
- an optional rating "cable test voltage" and the associated requirements and type tests are introduced;
- for testing the internal arc classification, when assigned by the manufacturer, more specific guidance is provided regarding the test arrangement, room simulation and arc initiation;
- a single phase to earth ignition is also recognised for internal arc testing;
- the Annexes A and B are renumbered Annexes AA and BB.
This publication is to be read in conjunction with IEC 62271-1:2007. The contents of the corrigendum of June 2015 have been included in this copy.

IEC 62271-203:2011 specifies requirements for gas-insulated metal-enclosed switchgear in which the insulation is obtained, at least partly, by an insulating gas other than air at atmospheric pressure, for alternating current of rated voltages above 52 kV, for indoor and outdoor installation, and for service frequencies up to and including 60 Hz. This second edition of IEC 62271-203 cancels and replaces the first edition of IEC 62271-203, published in 2003, and constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
- adopting the structure and the content to IEC 62271-1,
- harmonisation with IEEE C37.122,
- addition of the new Annex F and the new Annex G.
This publication is to be read in conjunction with IEC 62271-1:2007. The contents of the corrigendum of July 2013 have been included in this copy.

The contents of the corrigendum of January 2012 have been included in this copy.

IEC 62271-204:2011 applies to rigid HV gas insulated transmission lines (GIL) in which the insulation is obtained, at least partly, by a non-corrosive insulating gas, other than air at atmospheric pressure, for alternating current of rated voltages above 52 kV, and for service frequencies up to and including 60 Hz. This standard cancels and replaces IEC/TS 61640:1998. It is a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
- update to be in line with IEC 62271-1:2007 and 62271-203 and alignment of the voltage ratings and the test voltages;
- addition of new information for gas tightness and corrosion protection.
This publication is to be read in conjunction with IEC 62271-1:2007.

IEC/TR 62271-208:2009 gives practical guidance for the evaluation and documentation of the external electromagnetic fields which are generated by HV switchgear assemblies and HV/LV prefabricated substations. Basic requirements to measure or calculate the electric and magnetic fields are summarised for switchgear assemblies covered by IEC 62271-200 and IEC 62271-201, and for prefabricated substations covered by IEC 62271-202. This technical report applies to equipment rated for voltages up to and including 52 kV and power-frequencies from 15 Hz to 60 Hz.

This part of IEC 62271 applies to compact switchgear assemblies consisting of at least one switching device directly connected to, or sharing components with, one or more other devices such that there is an interaction between the functions of the individual devices. Such assemblies are made up of devices defined in 1.101 and are designed, tested and supplied for use as a single unit. The interaction between devices may be due to proximity, sharing of components or a combination of both. The assemblies may contain components of air insulated switchgear (AIS) only or a combination of AIS and gas insulated switchgear (GIS), so called mixed technology switchgear (MTS) and may be delivered entirely prefabricated or partially assembled.

This part of IEC 60050 gives the general terminology used in insulators. This terminology is consistent with the terminology developed in the other specialized parts of the IEV.
It has the status of a horizontal standard in accordance with IEC Guide 108.

IEC/TS 62271-210:2013 applies to metal enclosed switchgear and controlgear assemblies complying with IEC 62271-200 for metal enclosed and IEC 62271-201 for solid-insulation enclosed, ground or floor mounted, intended to be used under seismic conditions.

IEC 62271-206:2011 is applicable to voltage presence indicating systems (VPIS) incorporated in a.c. switchgear and controlgear covered by IEC 62271-200 or IEC 62271-201. Voltage presence indicating systems are devices used to provide information to operators about the voltage condition of the main circuit of the switchgear in which they are installed. This first edition of IEC 62271-206 cancels and replaces the first edition of IEC 61958. This edition constitutes a minor revision. The main changes with respect of the first edition of IEC 61958 are an actualization of references and the degree of protection which has been changed from IPXXB to IP2X.