Selecting a suitable explosion proof junction box is critical when you’re working in environments where flammable gases, vapours, or combustible dusts are present. These hazardous area enclosures are engineered to prevent internal explosions from igniting in hazardous atmospheres, safeguarding both people and infrastructure. But not all explosion proof boxes are created equal. From certifications to construction materials, there are several key factors for you to consider which junction box is right for your facility.
1. Understand Hazardous Area Classification
Before selecting an explosion-proof enclosure or light fitting, it’s essential to understand how hazardous areas are classified. In Australia, facilities are assessed using a zone-based classification system, which defines the likelihood and type of explosive atmosphere present.
Explosion-proof equipment is selected based on:
Zone indicates the frequency and duration that flammable gas, vapour, or dust may be present:
- Zone 0 – Constant or long-term presence of explosive gases
- Zone 1 – Likely presence of gases during normal operations
- Zone 2 – Gases are not likely under normal operations, or only for short periods
(For dusts, similar logic applies with Zones 20, 21, and 22)
Gas or Dust Grouping – Equipment is also matched to the type of hazardous material:
- Gas groups (e.g., hydrogen, methane, ethylene)
- Dust groups (e.g., carbon dust, grain dust, fibres)
At Transtech, we supply enclosures and lighting for hazardous areas. Check each product’s certificate for its zone rating. Typical sites are industrial applications where flammable gases, vapours, or combustible dusts may be present
Learn more about hazardous zone classifications.
2. Check for Relevant Certifications
Explosion proof boxes must be certified to meet local and international standards. International standards include:
- ATEX
- IECEx
- UL
Always match the enclosure’s certification with your region and specific hazard class.
Check the IECEx certificate for each enclosure against your site’s zone and gas group.
3. Choose the Right Material
Material selection directly affects the box’s durability, weight, and resistance to corrosion or impact. Common materials include:
- Aluminium: Lightweight and cost-effective but less corrosion resistant.
- Stainless Steel: Excellent for corrosive or marine environments.
- Glass-Reinforced Polyester (GRP): Non-metallic, lightweight, corrosion-resistant.
In facilities with high moisture, chemical exposure, or temperature extremes, investing in a more rugged material like stainless steel can extend service life and safety.
4. Understand the Environmental (IP) Ratings
Check for Ingress Protection (IP) ratings to ensure the enclosure can withstand:
- Water and dust ingress (IP65, IP66)
- Corrosion and UV exposure (important for outdoor use)
- Mechanical impact and temperature variations
Higher IP ratings are typically required for hazardous areas, including resistance to dust and water. For example, an IP66 rating ensures protection from powerful water jets and total dust ingress, which is critical in washdown or dusty environments.
5. Size and Layout Needs
Explosion proof boxes come in a variety of sizes. Evaluate:
- Internal space for terminal blocks, relays, or instruments.
- Mounting space and bracket compatibility.
- Cable entry positions and gland plate requirements.
Planning ahead for future expansion can help avoid costly replacements.
6. Evaluate Maintenance and Accessibility
Look for designs that simplify maintenance without compromising safety:
- Hinged doors for frequent access
- Removable gland plates for easy wiring
- Internal mounting rails or panels
- Modular setups that simplify system upgrades
Ease of maintenance can reduce downtime and enhance operational safety.
7. Tailor the Enclosure to the Application
Explosion proof boxes can be used to house:
- Electrical junctions
- Instrumentation, sensors and control systems
- Network switches and communication modules
Understanding the objectives of your requirement will determine the final specification and sizes of the boxes required to house the critical components.
Choosing the right explosion proof box isn’t just a matter of compliance, it’s about protecting people, infrastructure, and business continuity in high-risk environments. From certifications and materials to environmental protection and maintenance accessibility, every detail matters.
Why Choose Transtech Explosion Proof Enclosures?
- Check the IECEx certificate for the model you specify
- Specification support from Transtech for zone, gas group and cable entry requirements
- IP rating stated on each product datasheet
Contact Transtech today or email info@transtech.com.au and we’ll help you to find a suitable explosion proof or custom enclosure for your specific needs.