| 1. Verify the Ex marking | Read the complete marking on the luminaire and compare it with the certificate and product documentation. | IEC 60079-0 specifies general requirements for Ex equipment and its marking. IEC 60079-1 specifies requirements for protection by flameproof enclosures “d.” The standards alone do not confirm that a particular product is certified. | Illustrative gas marking: Ex db IIB T4 Gb. Confirm the exact marking and certificate for the equipment being considered. |
| 2. Match the hazardous-area zone and EPL | Check whether the area is classified for gas or dust, its zone, and the required Equipment Protection Level (EPL). | For gas atmospheres, Ga, Gb, and Gc are generally associated with Zones 0, 1, and 2 respectively. The area classification and applicable regulations determine the required protection; confirm suitability with the site’s hazardous-area documentation. | A luminaire marked Gb is generally intended for Zone 1 or Zone 2 gas areas, subject to its certificate and installation conditions. |
| 3. Check the gas or dust group | Compare the equipment group with the substances identified in the site’s area classification. | For gas, Group IIC covers more demanding gas hazards than IIB, which is more demanding than IIA. Dust equipment uses different group markings and protection requirements; IEC 60079-31 addresses protection by enclosure for dust ignition protection. | IIB equipment is not automatically suitable for a location requiring IIC. Check the actual gas or dust classification. |
| 4. Confirm the temperature class | Check the marked T-class and the maximum surface temperature against the ignition-temperature requirements for the hazardous substance. | For gas equipment, T1 to T6 correspond to maximum surface temperatures of 450°C, 300°C, 200°C, 135°C, 100°C, and 85°C respectively. The permitted temperature must be suitable for the hazard and ambient conditions. | T4 = maximum surface temperature of 135°C under the specified assessment conditions. |
| 5. Check ambient-temperature limits | Review the certified ambient-temperature range and any special temperature marking or installation restrictions. | Operating outside the stated range can affect equipment temperature and protection. Consider local extremes, direct sunlight, nearby heat sources, and the luminaire’s thermal performance. | Compare the product’s stated ambient range, such as −20°C to +50°C, with the actual site design conditions; use only the range shown in its documentation. |
| 6. Assess light output and placement | Review lumen output, beam distribution, mounting height, aiming, glare, and the required task illuminance. | Choose a photometric distribution suited to the area rather than relying on wattage alone. Use a lighting calculation to check illumination levels and uniformity at the working plane. | Request photometric data, such as an IES or LDT file, when preparing a project lighting calculation. |
| 7. Review enclosure rating and installation details | Check the ingress-protection rating, corrosion resistance, cable entries, mounting method, and installation instructions. | An IP rating addresses ingress protection; it does not replace Ex certification. Cable glands, stopping plugs, conduit entries, fasteners, and installation practices must be appropriate for the protection concept and certified equipment. | For outdoor or washdown locations, verify the specified IP rating and materials against the site environment, and follow the certified installation instructions. |
| Selection reminder: Confirm the hazardous-area classification, complete Ex marking, certificate scope, operating conditions, and installation requirements with the responsible hazardous-area professional before purchase or installation. |