IEC 62505-1:2016 is applicable to single-pole and two-pole alternating current (AC) circuit-breakers which are designed for indoor or outdoor fixed installations in tractions systems, and operated with an AC line voltage and frequency as specified in IEC 60850:2014. The main changes with respect to the previous edition are as follows:
- reflect the latest versions of standards referenced and remove text already included in the IEC 62271 series,
- extend the scope to include single-pole and two-pole circuit-breakers,
- rework Table 1 according to the changes of IEC 62497-1:2010.

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