ATEX Ex-Proof Electrical Installations: Zone Classification and Implementation

How to install ATEX ex-proof electrical installations in hazardous areas? Zone 0, 1, and 2 classification, certification, and implementation steps. AYÇE Industrial, Kocaeli.

ATEX Ex-Proof Electrical Installations in Industrial Facilities: Mandatory Requirements and Implementation Guide

In industrial environments such as petrochemical refineries, paint manufacturing plants, solvent storage facilities, pharmaceutical factories, and gas filling stations, airborne flammable gases, vapors, or combustible dust mixtures create severe explosion risks. Using standard electrical equipment in these hazardous locations is both legally prohibited and poses fatal risks.

The ATEX (ATmosphères EXplosibles) Directives represent mandatory engineering standards established by the European Union and enacted into Turkish national legislation to mitigate these explosion risks.

What Is a Hazardous Area?

A hazardous (explosive) atmosphere is defined as a mixture of flammable substances in the form of gas, vapor, mist, or dust with air, under atmospheric conditions, in which after ignition has occurred, combustion spreads to the entire unburned mixture.

Examples of hazardous industrial environments include:

• LPG and natural gas processing/distribution facilities

• Petrochemical refineries and storage tank farms

• Paint, varnish, and solvent production plants

• Flour mills, sugar refineries, and grain elevators (combustible dust explosion risks)

• Pharmaceutical and chemical manufacturing facilities

Zone Classification

According to ATEX standards, hazardous locations are categorized into specific zones based on the frequency and duration of the occurrence of an explosive atmosphere:

Gas/Vapor Atmospheres:

• Zone 0: Explosive gas atmosphere is present continuously or for long periods (greater than 1,000 hours/year).

• Zone 1: Explosive gas atmosphere is likely to occur in normal operation occasionally (10 to 1,000 hours/year).

• Zone 2: Explosive gas atmosphere is not likely to occur in normal operation and, if it occurs, will exist for a short period only (less than 10 hours/year).

Dust Atmospheres:

• Zone 20: Combustible dust cloud is present continuously or for long periods.

• Zone 21: Combustible dust cloud is likely to occur in normal operation occasionally.

• Zone 22: Combustible dust cloud is not likely to occur in normal operation and, if it occurs, will exist for a short period only.

Ex-Proof Equipment Protection Concepts

Distinct type-of-protection methods apply to specific zones:

Implementation Stages

1. Site Explosion Protection Document (EPD) and Hazard Risk Assessment

   A comprehensive site audit is conducted to map out all hazardous release points, resulting in a formal Hazardous Area Classification (Zone Map).

2. Equipment Selection

   ATEX-certified equipment compliant with IEC 60079 and EN 13463 standards is specified for each zone. The CE mark, Ex symbol, equipment group, category, temperature class, and certificate numbers are verified.

3. Cable and Cable Route Design

   Selection of heavy-duty ex-proof cable types (e.g., steel-wire armored, XLPE insulated), application of approved Ex cable glands (e.g., Ex d / Ex e certified), and verification of minimum separation distances.

4. Earthing and Equipotential Bonding

   To eliminate static electricity accumulation, all metallic enclosures, cable armor, and structural steel are connected to a dedicated equipotential bonding network.

5. Commissioning and Field Inspections

   Audit of the entire installation, insulation resistance testing, and grounding continuity measurements are executed under the supervision of a certified ATEX engineer.

6. Certification

   Issuance of an official Ex Installation Certificate and setting up the statutory periodic inspection schedule.

Regulatory Requirements

In Turkey, the deployment of ex-proof equipment in explosive atmospheres is mandatory under the following legal frameworks:

• Occupational Health and Safety Law No. 6331

• Ministry of Labour and Social Security — Regulation on the Protection of Employees from the Dangers of Explosive Atmospheres (Official Gazette No. 28633 dated April 30, 2013)

• ATEX Directive 2014/34/EU (Equipment Directive)

• ATEX Directive 1999/92/EC (Workplace Directive)

• IEC 60079 series standards

Non-compliance can result in immediate shutdown of site operations, administrative fines, and criminal prosecution in the event of an industrial accident.

Mandatory Periodic Inspection Schedule

Once commissioned, ATEX electrical installations must undergo routine inspection in accordance with IEC 60079-17:

• Detailed Inspection: Every 3 years

• Close Inspection: Annually

• Visual Inspection: Every 3 months

All inspections must be performed and logged by a certified Competent Person.

⚠️ Legal Notice and Disclaimer

The technical details, statutory references, and engineering standards cited in this article are provided solely for general informational purposes. Applicable regulations, technical specifications, and standards in Turkey are subject to updates. You are required to verify current provisions directly through official resources, including the Official Gazette, TEDAŞ, EMRA (EPDK), the Ministry of Labour and Social Security, and recognized standards organizations (TSE, IEC, IEEE).

Every industrial facility possesses unique infrastructure constraints, operational conditions, and site requirements. Consequently, no technical information contained herein should be interpreted as a definitive engineering recommendation or directly executed without site-specific engineering analysis.

AYÇE Endüstriyel Makina İnşaat Elektrik Taahhüt San. ve Tic. Ltd. Şti. disclaims all liability for any direct, indirect, financial, or legal damages arising from the implementation of the information presented above. Always engage an authorized electrical engineer or certified ATEX consultant to handle your hazardous location electrical engineering and compliance requirements.