MT 27 - TC 17/SC 17C/MT 27

IEC 62271-211:2024 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 for the transformer connection. This second edition cancels and replaces the first edition of IEC 62271-211:2014. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous edition:
a) re-numbering of clauses according to IEC 62271-1:2017,
b) Clause 3: updating definition about bushing (3.1), updating some pressure definitions (3.6, 3.7, 3.8, 3.9), rewording definition about proctor density (3.11), new term very-fast-front overvoltage (3.12),
c) Clause 5 (former clause 4): add a subclause 5.1 General, according to IEC 62271-1:2017 and IEC 62271-203:2022,
1) subclause 5.5: new first paragraph, rewording second paragraph,
2) subclause 5.8: modify the term "Rated duration of thermal short-time current" of the bushing,
d) Clause 6 (former Clause 5): restructure and rewording of subclauses:
1) 6.1 (former 5.3): requirements about gas and vacuum tightness of the transformer bushing
2) 6.3 (former 5.2): harmonization with IEC 62271-203:2022 about typical maximum pressure in service for SF6, other gases and gas mixtures,
3) 6.4 (former 5.8), rewording
4) 6.5 (former 5.1), some rewording and modification
5) 6.6 (former 5.4), some rewording, updated references
6) 6.7 (former 5.5), some rewording
7) 6.8 (former 5.6), some rewording
8) 6.9 (former 5.7), slight rewording,
e) Clause 7 (former clause 6) type tests: some rewording and clarifications about references,
f) Clause 8 (former clause 7) routine tests:
1) 8.2 (former 7.2): add a paragraph about SF6-mixtures and other gases than SF6,
2) 8.3 (former 7.3): update reference to relevant on-site test according to IEC 62271‑203:2022,
g) Clause 9 Guide to the selection of switchgear and controlgear (new): informative, to have a reference to IEC 62271-203:2022,
h) Clause 11 (former 10): updated headline and updated reference according to IEC 62271‑1:2017,
i) new Clauses 12 Safety and 13 Environmental aspects: Adding of references to safety and environmental aspects,
j) correction of errors in Corrigendum 2 of IEC 62271-211:2017,
k) modified orientation of Figure 1 to Figure 4 for easier reading of the tables.

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.