Overview
IEC TS 60079-32-1:2013/AMD1:2017 is an important amendment to the IEC technical specification that provides enhanced guidance on managing electrostatic hazards in explosive atmospheres. Published by the International Electrotechnical Commission (IEC), this document supplements Part 32-1 of the IEC 60079 series, focusing specifically on the safe handling of electrostatic charges related to non-metallic and metallic parts of electrical equipment used in hazardous environments.
This amendment updates references to related IEC standards and incorporates more conservative electrostatic charge threshold limits based on theoretical modeling and empirical data. It aims to ensure increased safety for industries operating in explosive atmospheres by minimizing the risk of ignition caused by electrostatic discharges.
Key Topics
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Electrostatic Hazard Management
The document outlines comprehensive requirements for preventing ignition in explosive atmospheres caused by electrostatic discharges. It specifies practical limits for surface resistance, charge thresholds, and capacitance values of materials used in electrical equipment.
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Material Requirements and Testing
Guidance is provided on selecting materials for external non-metallic parts, including paints, films, and coatings, to minimize electrostatic charge build-up. Thresholds include surface resistance limits (e.g., ≤100 GΩ at 30% relative humidity), material thickness constraints, and breakdown voltage parameters.
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Equipment Design Recommendations
The amendment emphasizes designing electrical equipment to avoid dangerous electrostatic charge accumulation during normal use, cleaning, and maintenance. This can be achieved through measures such as:
- Using conductive coatings or insulating layers bonded to conductive surfaces.
- Limiting the surface area of non-metallic parts exposed to hazardous atmospheres.
- Ensuring effective earthing of all external conductive parts.
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Group-Specific Requirements
Different guidelines are provided depending on equipment group classification (Groups I, II, III) and equipment protection levels (EPL). For example, Group III equipment has specific recommendations to prevent propagating brush discharges, often caused by extended flat conductive surfaces near plastic enclosures.
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Testing Procedures
The document references IEC 60079-32-2:2015 as the standard test method for electrostatic hazards, specifying conditions for measuring surface resistance, capacitance, and transferred charge to ensure compliance with recommended limits.
Applications
IEC TS 60079-32-1:2013/AMD1:2017 is applicable for manufacturers, designers, and safety engineers involved with electrical equipment intended for use in explosive atmospheres across various industries, including:
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Oil and Gas
Managing static electricity in refineries and processing plants to prevent ignition of flammable gases or vapors.
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Chemical Manufacturing
Designing electrical apparatus that reduces electrostatic risks during handling of combustible dusts and vapors.
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Mining and Dust Handling
Ensuring equipment used in dusty environments meets requirements to prevent electrostatic ignition due to dust-air mixtures.
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Pharmaceutical and Powder Processing
Minimizing electrostatic discharge risks related to powders or granules with explosive potential.
This standard assists industries to maintain compliance with international safety regulations while promoting operational safety and minimizing equipment downtime caused by electrostatic hazards.
Related Standards
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IEC 60079-0:2011 – Explosive atmospheres: Equipment – General requirements. Defines baseline requirements for equipment safety in explosive environments.
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IEC 60079-32-2:2015 – Explosive atmospheres: Electrostatics hazards – Tests. Specifies test methods for evaluating electrostatic risks applicable to materials and equipment.
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IEC 60079-14 – Explosive atmospheres: Electrical installations design, selection, and erection. Includes guidelines relevant to cabling and wiring external to electrical equipment.
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IEC 60243-2 – Electrical insulating materials: Methods for high voltage testing. Related to breakdown voltage measurements for insulating layers.
Using IEC TS 60079-32-1 alongside these related standards provides a comprehensive framework to mitigate electrostatic hazards in explosive atmospheres, enhancing global industrial safety.
By following the guidance laid out in IEC TS 60079-32-1:2013/AMD1:2017, organizations can ensure the development and deployment of safer electrical equipment, thus reducing the risk of ignitions due to electrostatic discharges and contributing to safer working conditions in hazardous locations.