The Ex e protection method is the most commonly used protection method. The main requirement is that no sparking devises or hot surfaces are allowed to be used in this type of enclosure. The inner parts of an enclosure is for the most part Ex e rated terminals, or Ex de rated indicator lights and switches. Deviation from the certificate normally means that a re-certification is required. This is typically the case if other devices than terminals are fitted.
Ex e terminal boxes
Ex e terminal boxes are produced according to EN/IEC 60079-7, using a technique where no sparking devises or hot surfaces are allowed and in addition other steps have been taken to increase the level of safety.
Terminal boxes are normally covered by a factory certificate that allows a given number of terminals to be fitted and guidance for fitting Ex rated glands. In this case no additional certification is required.
Terminal boxes can be supplied in almost any size and in different materials. The gland selection depends on the installation practise at the location and they can also be supplied in different materials. Special certification is also available should this be required.
Ex e control stations
Ex e control stations can basically be divided into two groups. In the smaller range you find a series of boxes that has a factory certificate that allows for installation of a given set of control devices that are Ex de certified with a “U” certificate. These boxes normally allow for up to 3 devices to be mounted in the box. The benefit is that no further certification is required, and the fact that they are standard, off the shelf items.
On larger control panels we have to tailor make a solution for each case, and then do a re-certification of the complete assembly. These types of control stations are used as indicator panels, or operator panels for field equipment.
The control stations may be supplied in any shape, and in different materials. The most common materials are GRP or 316 SS.