IEC 60947-5-3:2013 series provides additional requirements to those given in IEC 60947-5-2. It addresses the fault performance aspects of proximity devices with a defined behaviour under fault conditions (PDDB). It does not address any other characteristics that can be required for specific applications. This second edition replaces the first edition published in 1999 and its amendment published in 2005. It is a technical revision. This edition includes the following significant technical changes with respect to the previous edition: a) general principles of IEC 61508 series; b) classification according to the requirements of IEC 62061; c) classification according to ISO 13849-1.