IEC 60079-15:2017

Overview

IEC 60079-15:2017 - "Explosive atmospheres - Part 15: Equipment protection by type of protection 'n'" defines construction, testing and marking requirements for Group II electrical equipment with type of protection “n” intended for use in explosive gas atmospheres. This fifth edition (2017) replaces the 2010 edition and constitutes a technical revision. The standard covers sealed devices (“nC” / hermetically sealed), non‑incendive components (“nC”), and restricted‑breathing enclosures (“nR”) where the rated input voltage does not exceed 15 kV r.m.s. AC or DC (note: internal working voltages above 15 kV are included in scope, e.g., starters for HID luminaires). IEC 60079-15 supplements and modifies the general requirements of IEC 60079-0; where conflicts arise, IEC 60079-15 takes precedence.

Key topics and technical requirements

• Type of protection “n”: Requirements for sealed, hermetically sealed, non‑incendive and restricted‑breathing constructions used in explosive gas atmospheres.
• Construction and materials: Design criteria for enclosures, gaskets, seals, cable glands, windows and internal components to limit ingress and ignition sources.
• Type tests and routine tests: Procedures for type testing (including conditioning, voltage tests and enclosure tests) and routine verification (electric strength, temperature rise, and enclosure integrity).
• Temperature limits and surface temperatures: Maximum surface temperature guidance and methods to ensure equipment does not become an ignition source.
• Clearances, creepage and separations: Electrical insulation, creepage distances and separation requirements for safe operation in explosive atmospheres.
• Supplementary requirements by equipment type: Specific provisions for luminaires, machines, fuses, plugs/sockets, batteries/cells, current transformers and low‑power devices.
• Marking, documentation and instructions: Mandatory markings, documentation content and user instructions to support safe selection, installation and maintenance.

Practical applications and users

IEC 60079-15 is essential for:

• Manufacturers and design engineers of electrical equipment intended for hazardous gas environments (Group II).
• Test and certification laboratories assessing type of protection “n” compliance.
• Procurement, safety and compliance teams specifying safe equipment for industrial installations (lighting starters, control gear, sealed components, restricted‑breathing luminaires).
• Installers and maintenance personnel who need clear marking, documentation and routine test procedures.

Using IEC 60079-15 helps ensure equipment design minimizes ignition risk, meets international conformity requirements, and provides traceable tests and marking for safe use in explosive gas atmospheres.

Related standards

• IEC 60079-0 (general requirements for explosive atmosphere equipment) - IEC 60079-15 supplements and overrides where indicated.
• Other parts of the IEC 60079 series that address specific protection concepts, gas groups and installation/testing practices.