IEC 62271-106:2021 applies to AC contactors and/or contactor-based controllers and motor-starters designed for indoor installation and operation at frequencies up to and including 60 Hz on systems having voltages above 1 kV and up to and including 24 kV. This document also includes additional requirements for outdoor installations where the equipment is housed in an additional protective enclosure. This second edition cancels and replaces the first edition published in 2011. It constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: document numbered to correspond to IEC 62271-1 2017.