IEC TS 60079-42-2019 PDF

Full title and description

St IEC TS 60079-42-2019 — Explosive atmospheres - Part 42: Electrical safety devices for the control of potential ignition sources for Ex‑Equipment. This Technical Specification provides guidance for equipment manufacturers and assessors where electrical safety devices are used to reduce the likelihood that potential ignition sources become effective in Ex equipment located in explosive atmospheres; it applies to individual safety devices and to combinations of elements performing a safety function (for example sensor, logic system, final element). It also lists exclusions and limitations (mechanical safety devices, gas detection, systems to prevent formation of explosive atmospheres, explosion mitigation, and others).

Abstract

IEC TS 60079-42:2019 gives recommendations for design, assessment and application of electrical safety devices intended to control potential ignition sources associated with Ex equipment in explosive atmospheres. The document explains how a safety device may contribute to achieving a required Equipment Protection Level (EPL) for specific potential ignition sources, how combinations of device and Ex equipment can be assessed, and clarifies items outside its scope.

General information

• Status: Published — Technical Specification (IEC TS).
• Publication date: 17 April 2019.
• Publisher: International Electrotechnical Commission (IEC).
• ICS / categories: 29.260.20 (Explosive atmospheres / Equipment for explosive atmospheres).
• Edition / version: Edition 1.0 (2019).
• Number of pages: 48 pages.

Key bibliographic and status information above is taken from the IEC publication record for IEC TS 60079-42:2019.

Scope

This Technical Specification provides guidance for manufacturers, designers and assessors when electrical safety devices are used to reduce the probability that potential ignition sources become effective in Ex equipment situated in explosive atmospheres. It applies to electrical safety devices controlling potential ignition sources arising from electrical or non‑electrical Ex equipment and to combinations of elements performing a safety function (sensor, logic, final element). It does not apply to mechanical safety devices (e.g., pressure relief valves), to gas detection as a primary protective measure, to systems whose purpose is to prevent the occurrence of an explosive atmosphere (inerting/ventilation), nor to explosion mitigation measures.

Key topics and requirements

• Definition and classification of electrical safety devices used with Ex equipment.
• Guidance on assessing a safety device independently and as part of a combination (sensor → logic → final element).
• Relationship between a safety device and Equipment Protection Level (EPL) — how a device may contribute to meeting an EPL for a specific ignition source (with limitations).
• Requirements and recommendations for documentation, functional safety considerations, testing/verification and marking relevant to electrical safety devices in explosive atmospheres.
• Explicit exclusions and limits of applicability (mechanical devices, gas detection, inerting/ventilation, explosion mitigation, and simple EPL increases by merely adding a device).

Typical use and users

Primary users are manufacturers and designers of Ex equipment, safety engineers and system integrators working on equipment for hazardous (explosive) atmospheres, certification bodies and test laboratories, regulatory compliance specialists and asset owners/operators seeking guidance on specifying or assessing electrical safety devices that influence ignition-source risk in hazardous locations.

Related standards

IEC TS 60079-42:2019 is part of the IEC 60079 series on explosive atmospheres and is intended to be used alongside other parts of the 60079 family (for example IEC 60079-0 general requirements, IEC 60079-11 intrinsic safety, IEC 60079-14 installation practices, IEC 60079-17 inspection/maintenance) and relevant ISO 80079 documents addressing non-electrical Ex equipment. A matching IECEx Test Report Form (IECEx TRF 60079-42) was published to support test reports against this TS, and national adoptions/versions exist (for example DIN/VDE and NEK adoptions).

Keywords

explosive atmospheres, Ex equipment, electrical safety devices, ignition source control, Equipment Protection Level (EPL), IEC 60079, technical specification, functional safety.

FAQ

Q: What is this standard?

A: IEC TS 60079-42:2019 is a Technical Specification titled "Explosive atmospheres - Part 42: Electrical safety devices for the control of potential ignition sources for Ex‑Equipment" that provides guidance on electrical safety devices used to control potential ignition sources in equipment for explosive atmospheres.

Q: What does it cover?

A: It covers guidance for design, assessment and application of electrical safety devices (including combinations of sensor, logic and final element) intended to reduce the likelihood of ignition sources becoming effective in Ex equipment. It also lists exclusions (mechanical safety devices, gas detection as a protective measure, inerting/ventilation systems, explosion mitigation).

Q: Who typically uses it?

A: Equipment manufacturers, system designers, safety/instrumentation engineers, certification bodies, test laboratories, and facility owners/operators working with hazardous area equipment use this TS to inform device selection, assessment and documentation practices.

Q: Is it current or superseded?

A: The document was published on 17 April 2019 (Edition 1.0). As published on the IEC record it is a current Technical Specification (stability information indicated by IEC with stability to 2026). Users should confirm for any later amendments or a possible future revision with the IEC or national standards bodies if they require status beyond 2026.

Q: Is it part of a series?

A: Yes — it is part of the IEC 60079 series (standards and specifications for equipment for explosive atmospheres) and is intended to be used in conjunction with other parts of that series and with relevant ISO 80079 documents; an IECEx test report form was issued to support conformity assessment against this TS.

Q: What are the key keywords?

A: Explosive atmospheres; electrical safety devices; ignition source control; Ex equipment; equipment protection level (EPL); IEC 60079; functional safety; hazardous areas.