IEC 60079-26:2014

Overview

IEC 60079-26:2014 - Explosive atmospheres - Part 26: Equipment with Equipment Protection Level (EPL) Ga - specifies alternative construction, test and marking requirements for electrical equipment that must provide EPL Ga when a single standardized Type of Protection (for example Ex “ia”, Ex “ma”, Ex “da”) cannot be applied. EPL Ga corresponds to the very high level of protection required for Zone 0 (explosive gas atmosphere present continuously or for long periods). This third edition (2014) supplements and modifies IEC 60079-0 and takes precedence where the two standards conflict.

Key topics and technical requirements

• Scope and intent: Defines requirements for equipment that ensures protection against rare malfunctions and combinations of two independent malfunctions under manufacturer‑specified operational parameters. Applicable also where equipment is mounted across a boundary between zones (e.g., Zone 0 / Zone 1).
• Design and construction: Alternative measures where single standardized Types of Protection are infeasible. Topics include intrinsic safety, encapsulation, separation elements and construction rules for moving parts.
• Separation elements and process connections: Requirements and type tests for separation elements that prevent gas diffusion; process connections must provide sufficiently tight joints (IP66 added as an alternative to IP67 in this edition).
• Type tests and temperature evaluation: Defines tests to demonstrate compliance for separation elements and temperature assessment under specified conditions.
• Marking and instructions: Requirements for marking examples, EPL allocation and user information (including material specification for partition walls and guidance for separation elements and process connections).
• Relationship to IEC 60079-0: This part supplements/modifies general requirements; where conflicts exist, IEC 60079-26 takes precedence.

Practical applications

• Equipment that must operate inside Zone 0 but is mounted at a boundary with less-hazardous areas (e.g., sensors, transmitters, or actuators installed in vessel walls).
• Design of enclosures, feedthroughs and separation barriers where conventional single protection methods are not practical.
• Situations requiring documented type tests and marking to prove a very high level of protection for continuous explosive atmospheres.

Who should use this standard

• Electrical equipment designers and manufacturers targeting Zone 0 applications
• Certification and conformity assessment bodies
• Plant engineers, safety managers and procurement specialists in oil & gas, chemical and pharmaceutical industries
• Test laboratories and regulatory inspectors verifying EPL Ga claims

Related standards and keywords

• Related: IEC 60079-0 (general requirements for explosive atmospheres) and other parts of the IEC 60079 series (Types of Protection such as Ex “ia”, “ma”, “da”).
• Keywords: Equipment Protection Level Ga, EPL Ga, explosive atmospheres, Zone 0, separation element, process connection, intrinsic safety, encapsulation, IEC 60079-26:2014.