There are many misconceptions when it comes to hazardous area wireless installations. As experts in this field, we notice the same questions recurring time-and-again. Notably: As an end user, can I buy and install non-certified wireless equipment inside a pre-certified hazardous area enclosure myself?
This Q&A is based on a discussion we had on our recent podcast, which focused on this misunderstanding and what you can and cannot do under global Ex directives and health and safety legislation.
What is a pre-certified wireless enclosure?
Before resolving the misconception, it makes sense to set the groundwork of what a pre-certified wireless enclosure is. There is a lot of wireless technology out there, and customers want the latest generation. They also want to deploy this technology in potentially explosive atmospheres. However, there is a lag between the genesis of new technology and the inception of a hazardous area version with global certification. A pre-certified wireless enclosure allows users to overcome this issue. They provide the certification for different hazardous areas and are pre-configured for compatibility with different devices. Thus, it is possible to install a wireless device that isn’t Ex-certified into a hazardous area.
These enclosures can be pre-configured for a range of technologies, suiting the needs of different companies. Common systems include Wi-Fi, BLE, ultra-wide band, location systems, UHF RFID, LTE routers, and so on.
What drives end users to comply with the directives associated with deploying wireless devices in hazardous areas?
it’s always the end users responsibility to operate safely to ensure the equipment they’ve procured is the correct equipment and is installed correctly. Customers would naturally like to install the wireless device themselves to reduce bottlenecks and to accelerate onboarding of their new technology. However, it is the user who bears the responsibility if a device is non-compliant, even if the installation was carried out by a vendor. The standard for this is international standard 60079-14, which governs installations of any electrical equipment into a potentially explosive atmosphere. That standard uses the term certification a lot, but it is important for users to realise that this means third-party certification. There is no true option to self-certify in this instance. The certification process is having somebody else, an independent, accredited, verified, third party say something is correct.
The problem with self-declaration, or self-attestation, is often the people who’ve undertaken the activity are not qualified. Subsequently, they may not realise that self-attestation means bearing the full responsibility for that piece of equipment. It is better to use properly certified equipment as you are less likely to be challenged by inspectors, insurers or the Health and Safety Executive. It can be difficult to demonstrate the competence required to do anything yourself internally versus just buying a piece of certified equipment. These are the main drivers of certification.
How does this differ for manufacturers who produce Ex equipment?
There are a number of certification processes, ATEX, UKCA, IECEx, but they tend to follow the same route, same standards, and the same necessities for the accredited certification bodies. It is usually a two-stage process where the equipment manufacturer supplies a sample and a set of schedule drawings. The sample is tested to prove the product is safe. However, it is the drawings that are certified, not the product, because the manufacturer typically wants to create multiple units.
The certificates ultimately issued come with a set of drawings which cover the scope of the certificate, and these schedule drawings are the IP of the OEM manufacturer. The end user will never have access to them.
The internal layout, the internal geometry, and the power that a piece of equipment may dissipate inside the enclosure, must all be empirically tested. Everything intended for use within the enclosure must be listed on the schedule drawings, and there can be no deviation from those drawings when it comes to manufacturing. Which means any subsequent substitution, such as sourcing parts from a different vendor, might invalidate the certification. A second certificate, known as a quality assurance notification, or for America, they do what’s called a follow-up service audit, is needed for manufacturers to actually produce the product.
The manufacturer will also be audited periodically. It varies from four times a year for the North American systems to yearly or every 18 months for ATEX and IECEx. the process involves rigorous checks to ensure the drawings are being followed exactly, that they are only manufacturing what they have certified, and all checks and testings have been carried out. They need these two certificates to place a product on the market. Therefore, the end user can be assured that their product has been verified by an accredited, recognized third party and that is the actual product that they have received.
How do manufacturers apply the relevant frameworks?
At Extronics, for ATEX and IECEx we follow the standard 80079-34, which is based on the ISO 9001 standard. It is well-aligned, but there are many extra requirements on a manufacturer—controlling and selecting suppliers, or controlling calibrated equipment, for example. Some of the things that we would do above and beyond what an ISO 9001 manufacturer would do is offer highly specific inspection of incoming goods and being very specific about what should be on a circuit board, or about a particular makeup of an enclosure. We are also extremely conscious of competency and training, ensuring staff have the necessary skills and experience to carry out regular assessments.
Does this approach differ for North America?
Most of the states in the US follow the NFPA70 (National Fire Protection Association) regulations, which is the set of guidance about how electrical equipment is installed and selected for use in hazardous environments. Within that document is article 110, which talks about which listed or tested equipment shall be used.
The difference between the IECEx and the IEC ATEX and the North American scheme is that audit is quarterly. It is based on the ISO 9001 regulations, but it focuses on the materials, incoming goods, quality assurance, and how you are ensuring those parts meet the requirements set out in your certified drawings etc
Where does the responsibility fall for conformity when the product is placed on the market?
Responsibility always lies with the end user or whoever is going to be using the equipment. Customers must select equipment based on the category or EPL as it is more commonly known. Category one, two, and three for ATEX or EPL, GAGBGC, for example, for IEC for the rest of the world. The customer or end user is compliant by buying third party certified equipment.
However, they still must install it correctly, inspect it correctly which is covered by a whole range of standards, 14, 17, and 19 which are applicable to the end user. Manufacturers and end users operate in different spheres entirely, and it is not expected that the end user would understand the product certification. This falls on the heads of manufacturers, which highlights why the certification process is important.
Even following a partially populated box instruction can be extremely difficult when you realise that you can’t put certain things inside the enclosure, such as certain batteries or RF devices. There is a whole series of rules, which unless you’ve undertaken some fairly specialist training, you just couldn’t possibly know these rules and you’d have to read hundreds of pages of standards to derive all these rules, which is why they tend to separate out into different disciplines. The discipline for the equipment manufacturer to ensure the equipment’s correct and then the discipline for the equipment installer to ensure the equipment is selected correctly, installed correctly, and maintained correctly.
Listen to our podcast for the full talking points about installing non-certified wireless equipment inside a pre-certified wireless enclosure and what you can and cannot do under Ex derectives. For more information or to see how Extronics can help you with your hazardous area wireless connectivity, please contact a member of our team on +44 (0)1606 738 446 or email us at firstname.lastname@example.org.