IEC 62271-110:2012 is applicable to a.c. circuit-breakers designed for indoor or outdoor installation, for operation at frequencies of 50 Hz and 60 Hz on systems having voltages above 1 000 V and applied for inductive current switching with or without additional short-circuit current breaking duties. The standard is applicable to circuit-breakers in accordance with IEC 62271-100 that are used to switch high-voltage motor currents and shunt reactor currents and also to high-voltage contactors used to switch high-voltage motor currents as covered by IEC 62271-106. For circuit-breakers applied to switch shunt reactor currents at rated voltages according to IEC 62271 1:2007 Tables 2a and 2b, combined voltage tests across the isolating distance are not required (refer to 4.2). This third edition cancels and replaces the second edition published in 2009 and constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: - former Table 2 has been split into three new tables to conform with IEC 62271-100 and to address actual in service circuit configurations. - the criteria for successful testing has been revised to a more explicit statement (see 6.114.11a). - comments received in response to 17A/959/CDV and 17A/981/RVC have been addressed. The contents of the corrigendum of October 2012 have been included in this copy. This publication is to be read in conjunction with IEC 62271-1:2007.