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Simplifying the challenges of Zone 2 with IP67 Remote I/O solution

Published:  27 May, 2025

ATEX compliance in industrial environments can often seem like a complex and costly hurdle, especially when it comes to equipment used in potentially explosive atmospheres. Zone 2, in particular, presents its own unique set of challenges, as it requires special precautions, yet for most of the time, it can seem just like any other non-hazardous part of the factory. This article explores how Zone 2 can be less painful to manage, particularly through the use of IP67 Remote I/O solutions, which can reduce both cost and complexity without compromising safety.

What is Zone 2, and why is it challenging?

Before diving into solutions, it’s helpful to understand the context of Zone 2. ATEX zones are classification systems used to define areas where explosive atmospheres may occur due to the presence of gas or dust.

For gas, the zones are defined as follows:

Zone 0: The highest risk zone, where explosive atmospheres are continuously present, or present for long periods (more than 1000 hours per year).

Zone 1: A moderate-risk zone, where an explosive atmosphere is likely to occur under normal operation (10 to 1000 hours per year).

Zone 2: The lowest risk, where explosive atmospheres only occur under abnormal conditions (less than 10 hours per year).

Similarly, dust zones (20, 21, and 22) correspond to different levels of risk associated with explosive dust clouds.

Zone 2, while lower risk compared to Zones 0 and 1, presents a unique challenge because, for more than 99.9% of the time—approximately 8750 hours per year—the area behaves like any other non-hazardous environment. Yet, stringent precautions must be observed when equipment is used, maintained, or installed in these areas. These measures, while essential for safety, incur higher costs and extended maintenance times.

While no-one thinks that special precautions in the higher zones are not required, to use an analogy, of a domestic kitchen with a situation similar to a Zone2, e.g. a gas leak, would you search for the leak in your house with a match? So how can we make it less painful?

Making Zone 2 management more efficient

In an ideal world, the risk would be eliminated entirely, and the area could be declassified, removing the need for ATEX compliance altogether. However as this is rarely feasible or practical, what else can we do?

The use of non ATEX equipment in a suitable Zone 2 certified enclosure may well reduce the initial cost of the equipment but this is false economy.

The more sensible thing to do is to use products designed for use in Zone 2 which don’t require any enclosure, can be mounted directly to the machine and use plug-in connectors everywhere. This can reduce maintenance costs enormously

The elimination of enclosures makes access far easier, with a gas-free certificate no longer required, to confirm that there is no explosive atmosphere before the cabinet can be opened.

The use of quick disconnect connections ensures that a product can be replaced with no subsequent need for extensive electrical testing. Wiring terminals, as well as being the point of failure when replacing any product, also take far longer to repair. Typically a wiring terminal takes 5 – 15 minutes per connection, requires tools (screwdriver, torque wrench, wire strippers, ferrules) and has a high risk of miswiring, loose connections and broken wires. A quick disconnect plug and socket takes between 30 seconds and 2 minutes per plug, requires no tools and eliminates misconnections.

Solution for Zone 2

One company which offers a comprehensive suite of products that provide solutions for both hazardous and non-hazardous environments is Turck Banner. Its products cover all ATEX zones, with a range of sensors, interconnecting cables, PLCs, and fieldbus solutions tailored specifically for Zone 2.

The parent company, Turck, is an industry leader in producing IP67, IP68, and IP69K-rated fieldbus products that can be mounted directly onto machines. This capability significantly simplifies machine reconfiguration, as components can be easily relocated between production lines, and tooling changes become more efficient.

Products designed for direct machine mounting are exposed to more challenging environmental conditions, such as higher temperatures or physical wear, compared to those housed in enclosures. Turck Banner addresses these concerns by offering rugged products with metal housings and extended operating temperature ranges. For example, the TBEN series of multiprotocol digital I/O modules are certified for ATEX Zone 2/22, cULus, IECEx, and CCC approvals, with IP65/IP67/IP69K protection and a temperature range of -40 to +70°C.

The inclusion of IMC isolating barriers and brackets for the TBEN and IMC products further ensures that connections are secure and protected, meeting the requirements for Zone 2 while offering additional safeguarding for cables.

These products are not only robust but also versatile, making them ideal for companies with global operations, whether equipment is deployed in the tropics, Arctic regions, clean rooms, or quarries.

Turck also emphasised to PWE that it is the only company to offer safety-rated remote I/O modules for Zone 2/22 with a SIL3 rating. These modules, designed for direct mounting, provide additional layers of protection and ensure that safety protocols are fully integrated into Zone 2 applications. Featuring IP65, IP67, and IP69K protection, and with a temperature range of -40 to +70°C, these products support CIP Safety and Profisafe protocols, ensuring that safety is maintained without sacrificing performance.

In addition to remote I/O, Turck Banner’s range includes lighting, indication, wireless I/O, barriers, signal conditioners, RFID solutions for both Zone 1 and 2, and a broad selection of sensors. These products provide comprehensive coverage for all ATEX zones, making Turck Banner a one-stop shop for hazardous area solutions.

Supporting every installation type

Not all businesses are looking to use fieldmounted devices. For those who prefer alternative solutions, Turck Banner says it also offers the EXCOM range, which supports all zones and non-EX areas. EXCOM provides flexibility, allowing users to hot-swap cards and power supplies even in Zone 1. Additionally, bespoke cabinets can be tailored to specific customer needs, offering a turnkey solution that meets all the necessary compliance standards.

The benefits of remote I/O in Zone 2 applications

For businesses embracing the concept of Zone 2/22 remote I/O, the benefits are clear:

Easier maintenance: With plug-and-play connections, troubleshooting and replacement become faster and simpler.

Reduced time-to-market: Less downtime and simplified installations accelerate project timelines.

Greater flexibility: Modular machine designs allow for easy reconfiguration and adaptation to changing production needs.

Lower lifecycle costs: Reduced maintenance and installation time result in significant cost savings over the lifetime of the equipment.

Managing ATEX Zone 2 requirements doesn’t have to be a complicated or costly endeavour. By using advanced, Zone 2-compatible remote I/O products, businesses can simplify maintenance, reduce costs, and enhance operational efficiency.

For further information please visit: https://www.turckbanner.co.uk/en/

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