IEC 62271-109:2008+A1:2013 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. 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. This consolidated version consists of the second edition (2008) and its amendment 1 (2013). Therefore, no need to order amendment in addition to this publication.

This publication is to be read in conjunction with IEC 62271-100:2008 and IEC 62271-1:2007.