Explosive atmospheres — Part 26: Equipment with separation elements or combined levels of protection Atmosphères explosives — Partie 26 : Appareil avec éléments de séparation ou niveaux de protection combinés
1 Scope
This part of IEC 60079 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.
EXAMPLE: Equipment installed in the wall of storage tanks located in Zone 1 and containing Zone 0 inside.
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. Suitable measures can be selected from ISO 80079-37 or IEC TS 60079-42.
This document also specifies requirements for the combination of two Types of Protection, each
with EPL Gb, to achieve EPL Ga. Examples are included in 4.2.
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. The requirements of the IEC 60079 series of Standards cover protection with respect to explosion
hazard only. The CSA C22.2 No. 60079 series of Standards (based on the adoption of corresponding IEC
Standards) is to be used in conjunction with other applicable Standards containing the appropriate
electrical safety requirements for general use equipment.
This Standard applies to electrical installation systems intended to be installed or used in accordance
with CSA C22.1, Canadian Electrical Code Part I.
General requirements applicable to electrical products are provided in CSA C22.2 No. 0. Note 1A: The ISO 80079 series of Standards provide guidance for evaluating non-electrical risk; however, at the
time of publication of this Standard they have not been adopted as Canadian standards.