ATEX Certification for LoRaWAN® Gateways & Sensors

LoRaWAN® proves to be a reliable long-distance communication technology. It stands out with cost-efficiency, security features, and flexible deployment capabilities in various environments. Nevertheless, the law mandates that special consideration must be given to applying LoRaWAN® in hazardous locations and explosive atmospheres. These environments involve gases such as methane, propane, hydrogen, acetylene, etc.

Additionally, processes like grain handling and textile manufacturing may entail dust. Since standard equipment cannot safely operate in such conditions, it is possible to obtain the required certification by only using tailored design methods and testing.

Terminology clarification

Terminology and regulations applicable to potentially hazardous environments can vary by country and region. For example, in North America, these environments are commonly referred to as HazLoc (Hazardous Locations). Historically, they were regulated by the system of Hazard Class and Division, but now they are aligned with the internationally recognized Zone system.

In contrast, within the European Union, areas with potentially explosive atmospheres are known as ATEX, which stands for the French term “Atmosphères Explosibles.” In the United Kingdom, the regulations are nearly identical to ATEX but are distinguished by the term “UKEx.”

Modern regulations for these environments are generally based on the Standards Relating to Equipment for Use in Explosive Atmospheres, or the IECEx System. These standards have been developed by the global standardization organization, the International Electrotechnical Commission (IEC).

The term “Ex” often serves as the universal indicator for hazardous locations and explosive atmospheres. Moreover, it is incorporated into the TEKTELIC product naming convention to distinguish between ordinary location product versions and those that are explosive atmosphere certified.

ATEX Zones

Areas prone to the formation of explosive atmospheres due to flammable gases, vapors, or dust are called ATEX Zones or IECEx Zones. The illustration below demonstrates the transport fuel delivery process as an example.

Classification of ATEX Zones is determined by factors like the frequency, duration, and source of the explosion risk associated with either gas or dust.

Equipment certification

In the context of regulating hazardous locations and explosive atmospheres, two primary aspects must be considered:

• Equipment design and certification (products).
• Location classification and system deployment (workplaces).

Within the EU, regulations adhere to the ATEX directives. Firstly, Directive 2014/34/EU governs equipment design and certification. Secondly, Directive 1999/92/EC pertains to site classification and system deployment.

If equipment certification is required, it is obtained through a notified conformity assessment body (notified body), enabling the application of the globally recognized CE mark.

On the other hand, North American regulations come from government agencies. These include the US Department of Labour’s Occupational Safety and Health Administration (OSHA). In that case, the regulations are founded on standards like the National Electrical Code (NEC) maintained by the National Fire Protection Association (NFPA).

At the same time, OSHA’s Nationally Recognized Testing Laboratory (NRTL) Program controls equipment certification. It licenses organizations like CSA, UL, QPS, etc., to verify whether products meet the industry standards (increasingly based on IECEx standards).

As an equipment manufacturer, TEKTELIC places a strong emphasis on equipment design and certification. TEKTELIC’s products may bear the NRTL mark, CE mark, and other national marks authorized by the IECEx Equipment Certification Scheme.

Equipment selection

Planning LoRaWAN® deployment in hazardous locations and explosive atmospheres, Zone certification selection is determined by the following factors:

• Fixed or mobile nature of equipment.
• Equipment types, e.g., gateways or sensors.

There are numerous design solutions for equipment depending on a specific deployment zone. For instance, the Intrinsic Safety method of protection is frequently employed for Zone 1/21 certified LoRa sensors. Some of these sensors include TEKTELIC’s PELICAN Ex outdoor-rated GPS asset tracker or SEAL Ex wearable tracker. The rating in question empowers these devices to move around commonly accessible areas of a site without restriction.

Concerning gateways, Zone 2 is often selected as a sufficient fixed location. The TEKTELIC KONA Mega Ex Gateway utilizes:

• Increased Safety (or Non-Arcing in North America) protection method as a basis.
• Dust Protected (or Dust-Tight in North America) method for Dust Zone 22.
• Intrinsic Safety for LoRa and cellular antenna ports, enabling simple, low-cost antenna selection and constraint-free maintenance.

TEKTELIC offers a solution for Zone 1 gateway deployment. It is based on the Flame-Proof (or Explosion-Proof in North America) protection method with Dust Protected Zone 21 rating and Intrinsic Safety rating for antenna ports.

Equipment marking

When evaluating the suitability of Ex equipment, it is essential to distinguish between location classification and equipment protection level or category. A zone represents a location classification and is not part of the equipment certification marking.

Instead, Ex equipment is labeled with the following:

• Equipment protection level (EPL).
• Equipment category with atmosphere type (for ATEX).
• Other information that determines location suitability.

The marking below is an example of an intrinsically safe sensor suitable for use in most Zone 1 Gas and Zone 21 Dust environments. The repetition observed is specifically linked to the additional requirements imposed by the ATEX Directive. Each certification for Gas and Dust environments has its distinct marking line.

The critical element in this marking is the equipment protection level, as it specifies the zone for which the equipment is suitable.

Furthermore, the following table shows a correlation between the equipment protection level (and the ATEX equipment category/atmosphere) and the respective location’s zone classification. The highlighted portion in green represents the sensor example mentioned above.

Selecting equipment becomes much simpler when the supplier has identified and implemented optimum solutions for common use cases. With TEKTELIC’s solutions, which include global certifications for both sensors and gateways, the challenge of hazardous locations and explosive atmospheres is no longer a hindrance to LoRaWAN® deployment.