MT 44 - TC 17/SC 17A/MT 44

IEC 62271-109:2019 is available as IEC 62271-109:2019 RLV which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.
IEC 62271-109:2019 is applicable to AC series capacitor by-pass switches designed for outdoor installation and for operation at frequencies of 50 Hz and 60 Hz on systems having voltages above 52 kV. It is only applicable to by-pass switches for use in three-phase systems. This document is also applicable to the operating devices of by-pass switches and to their auxiliary equipment. This third edition cancels and replaces the second edition published in 2008 and Amendment 1:2013. This edition constitutes a technical revision. This edition contains the following significant technical changes with respect to the previous edition:
a) the document has been restructured according to edition 2.0 of IEC 62271-1;
b) the rated voltage assignation across the by-pass switch has been aligned to the rule defined in IEC 60143-1;
c) clarification has been given regarding rated continuous current of compensated and uncompensated line;
d) some clarifications have been given following a loss of "suitable precautions";
e) as per Amendment 2 of IEC 62271-100, the section "Rated time quantities" has been moved to Clause 6 under "Time quantities";
f) as per Amendment 2 of IEC 62271-100, the section "Test for static mechanical loads" have been moved to Clause 6 under "Static mechanical loads";
g) additional rules have been introduced for vacuum interrupters during impulse tests;
h) additional clarifications have been given regarding the number of reduced impulses during impulse tests;
i) a wider tolerance on the current damping during by-pass making current test-duty has been introduced.

IEC 62271-109:2008 is applicable to a.c. series capacitor by-pass switches designed for outdoor installation and for operation at frequencies of 50 Hz and 60 Hz on systems having voltages above 52 kV. It is only applicable to by-pass switches for use in three-phase systems. This standard is also applicable to the operating devices of by-pass switches and to their auxiliary equipment. This second edition cancels and replaces the first edition, published in 2006, and constitutes a technical revision. This standard is to be read in conjunction with IEC 62271-100 and IEC 62271-1 (2007), to which it refers and which is applicable, unless otherwise specified in this standard. The main changes with respect to the previous edition are listed below:
- By-passing test duty has been split.
- Equivalence regarding applicability of test parameters were reviewed.
- Recovery voltage waveshape during insertion test duty has been recalculated and optimized. An explanatory note on the calculation of the recovery voltage is given in Annex F.
- Withdrawal of the electrical endurance class BP2. Such devices are now covered in informative Annex E.
- Addition of Annex D which gives examples of typical by-pass switch ratings.