IEC 60079-26:2021 specifies requirements for construction, testing and marking for Ex Equipment that contains parts of the equipment with different Equipment Protection Levels (EPLs) and a separation element. This equipment is mounted across a boundary where different EPLs are required, for example between different gas hazardous areas, dust hazardous areas or gas hazardous areas adjacent to dust hazardous areas.
Separation elements are considered for both electrical and non-electrical equipment. If mechanical energy can be transformed into a potential ignition source, additionally an ignition hazard assessment in accordance with ISO 80079-36 is performed and appropriate measures are undertaken.
This document also specifies requirements for the combination of two Types of Protection, each with EPL Gb, to achieve EPL Ga.
This document supplements and modifies the general requirements of IEC 60079-0. Where a requirement of this document conflicts with a requirement of IEC 60079-0, the requirement of this document takes precedence. This fourth edition cancels and replaces the third edition and constitutes a technical revision.
Please see the IEC 60079-26:2020 foreword for a description of the main changes with respect to the previous edition.