FEATURE ENCLOSURES
Choosing the right type of electrical enclosure
ENCLOSURE ENVIRONMENT The selection of the correct type of enclosure is paramount to a reliable installation. Ensuring that this is done correctly will help maximise the longevity of the enclosures themselves, as well as the electrical equipment being housed within. The choice of enclosure ultimately comes down to its intended usage. Enclosures are used in a range of environments, so their design needs to account for this. Some examples include rain and moisture, temperature extremes, road salt, exposure to chemicals and UV, ingress of insects and rodents, and electromagnetic interference.
Steve Slater, product manager for Electrical Installation at HellermannTyton, explores some of the key considerations involved in choosing the right type of electrical enclosure, and how a solid understanding of end-user requirements can help specifiers reach the correct decision, first time
E
lectrical enclosures are a big business. With the global enclosure industry
generating billions of pounds each year, and further forecasts predicting enviable growth of 7.9 per cent CAGR, the outlook is positive. There are a host of developments underway which account for the growing demand for enclosures, namely the rise of fibre optic networks, key changes in legislation, and the increased role of automation in manufacturing, to name a few. An electrical enclosure is more than just
18 MARCH 2017 | ELECTRICAL ENGINEERING
a cabinet that is attached to the wall or a floor. It provides protection from electric shock to people and animals, while also providing environmental protection to the devices contained within. The design of enclosures has therefore evolved to meet an ever-sophisticated range of technical and functional requirements. With so many potential enclosures to choose from, depending on the application, installers need to be aware of the variables at play and how these will impact on the quality of the solution.
ENCLOSURE TYPES Enclosure types are diverse, ranging from small connection boxes with limited ingress protection, to sophisticated enclosures for motor control centres (MCC) and switch rooms. For data applications, enclosures are increasingly used to house servers and network switches. The use of enclosures for jointing cables that are filled with epoxy or gel has grown significantly in recent times, as these offer excellent resistance to moisture and a safe method of jointing cables. This type of cable jointing method offers a speedy and cost effective method for jointing damaged cables or extending a circuit. The growth of fibre optic technology has demanded a new breed of enclosure types to handle the growth of installations such as fibre to the home (FTTH) and fibre to the cabinet (FTTC).
MATERIALS Available in a variety of materials, including mild steel, stainless steel, glass reinforced plastic (GRP), ABS, and polycarbonate, the selected material must be suited to the intended environment in which the enclosure is to be used. In outdoor applications, it is likely that enclosures will be exposed to the elements and must therefore be resistant to the effects of rain, salt spray (when located by a road or the sea) and ultraviolet light. While stainless steel would work perfectly well in such cases, GRP is rapidly becoming the material of choice, due to its impressive resistance to corrosion, sunlight and durability. Continued on Page 20...
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