An Ex nR or restrictive breathing enclosure removes the fuel element of an explosion by stopping any flammable gasses entering the internal enclosure. In doing so, potentially explosive gases never come into contact with hot surfaces or an ignition source potentially present inside the enclosure. Restrictive breathing enclosures are only certified to Zone 2 hazardous areas, where the area is considered safe in normal operation with flammable gases only present in fault conditions. The technique ensures the cumulative concentration within the enclosure does not exceed the lower explosive limit for the gas or vapor concentration over short and long periods of time. A Ex nR enclosure typically has the following characteristics: Lightweight metallic or non-metallic construction Designed to prevent flammable gases entering High ingress protection levels Tightly sealed iWAPXN3 Zone 2/Division 2 Hazardous Area Enclosure […]

An Ex d enclosure is designed to contain an explosion and stop any flames, sparks, and hot gases from escaping into the surrounding atmosphere should an internal explosion occur. In addition, an Ex d enclosure protects the fitted equipment against external moisture, dirt, dust, or water. The enclosure may house equipment such as, contactors, relays, power supplies, transformers, radio devices and other electrical equipment with potentially hot surfaces. Sometimes referred to as ‘flameproof’ or “explosion-proof”, an Ex d enclosure includes what is known as a flame path. The flame path design can vary depending on the construction of the Ex d enclosure system. Flame Path Flame paths are gaps within the enclosure that, if an internal explosion occurs, ensure that by the time the flame has reached the end of the flame path it has […]

Extronics’ trusted partner, MMX Communications needed a custom wireless network solution for a major petrochemical company. The client required a secondary communications link to an existing offshore platform. The secondary link would support a sub-sea cable and use microwave Line of Sight equipment. The electrical equipment also needed to be installed and work in an area on the platform that may have an explosive atmosphere present. Customer Requirements MMX Communications client needed to deploy a NEC iPasolink Digital Radio System and two outdoor units for the radios into a Zone 1 hazardous area of the site. The iPasolink hardware is too big for a lot of standard wireless access point systems available; MMX needed to find a manufacturer who could design a custom solution that still met all the required standards for operations in the […]

The standards surrounding the installation of a wireless access point in hazardous areas are often misinterpreted. It is not uncommon to think you can purchase a NEMA 4X or Ex e enclosure and simply install any wireless access point into your hazardous area. This is not true and overlooks a key clause of the standard assigned to deploying electrical equipment in hazardous areas. This article explains key aspects of the standard to consider when deploying wireless devices into hazardous areas. It also addresses why you cannot just use a NEMA 4X or Ex e enclosure to install none certified wireless access points in hazardous areas. Zone 2/Division 2 Hazardous Area Standards for Deploying Wireless Access Points There are many devices on the market, including WiFi Access Points, UHF RFID Readers, LoRa or BLE Gateways and […]

Received signal strength indication (RSSI) location principle uses received signal strength to determine the location of the transmitting device. A wireless device sends a signal out and that signal is received by a gateway or access point. Multiple access points will pick up the signal and from that a received signal strength is determined by each access point. The further away the access point to the transmitting device the weaker the signal. In comparison, the closer the transmitting device is to an access point the stronger the received signal strength. Location is determined by receiving the signal from multiple access points and taking the different measurements to make an approximation of location by trilateration. The approximate location can then be positioned on a map. For example, an asset or a worker wearing a Wi-Fi RTLS […]

John Hartley, CEO of Extronics, talks about the next generation of site wide Real Time Location Systems (RTLS) using hybrid technology for improved worker safety and asset tracking. Why is location tracking important for worker safety? The safety of workers, whilst always important, is moving higher up the list of priorities for investment. Companies operating within the process industries are always looking to ensure their workers are safe whilst making sure they are getting the biggest ROI possible. Back in 2005, when the first intrinsically safe Active RFID Wi-Fi RTLS tags were made, the goal of the oil and gas industry was to use technology to improve worker safety. This is still true today, though adoption has been slow for various reasons, such as the maturity of available technology and concerns over costs and benefits. […]