Hidden security

It does not need an analyst to identify that requirements for security equipment within electrical and building services installations have increased dramatically over the past couple of decades. Crime and vandalism against property continues to rise and paradoxically with greater use of electrical countermeasures comes a heightened need to protect those systems. While most attention is paid to specifying the ‘clever’ equipment such as cctv cameras, sensors and surveillance devices, it remains the enclosures that the equipment is housed in that provide the strongest link in the security chain.

In practicality there is no such thing as a security enclosure, since security and surveillance systems are never regarded as being a single application. Clearly, the needs for protecting a cctv camera and its control box mounted high on a building or on top of a pole are very different from the requirements of the 19 inch racks housing the system’s data processing equipment within the building.

It is useful, therefore, to consider the characteristics of the different applications involved in typical security installations and to relate those to the features and design of the enclosure required by each.

Under surveillance

For camera surveillance and recording, the most obviously vulnerable enclosure is the camera control box. For the operator, inaccessibility and exposure to harsh conditions are two key factors for consideration. For the criminal or vandal, the cameras and their controls are an obvious target.

To satisfy the environmental circumstances, plastics enclosures offer many advantages over traditional metal boxes, being both lightweight and corrosion-free. Traditionalists might argue that plastics are the last material one would specify as a barrier against missile-throwing hooligans.

However, modern polycarbonate enclosures are inherently maintenance-free, are unaffected by the worst weather conditions, do not degrade under the effects of ultraviolet light and withstand the most aggressive attention of vandals. Typically, these enclosures are rated to IP65 or 66 and can be supplied in a variety of sizes and configurations.

Relay squad

Signals from surveillance sensors and cameras are usually collected at relay stations that are frequently mounted outdoors. Again, corrosion resistance and anti-vandal measures are primary considerations. Compounding the problem, such relay cabinets are large and usually mounted at ground level where they are even more prone to attack.

Glass reinforced polyester (GRP) enclosures provide an inexpensive means to meet the requirements of such outside cabinets. Apart from the obvious benefits of being corrosion free and needing no painting, these cabinets also need no maintenance and provide IP66 protection. Typically, cabinets can withstand temperatures from -50°C to +130°C, which more than covers the extremes of British weather. Look out for enclosures that have an IK10 impact resistance rating. This, in plain terms, means they will withstand anything a vandal throws at them, including boots and hammers.

One interesting security application where this type of enclosure has found use is in rail transport. This is a big growth area for security installations where GRP enclosures have particular benefits. When mounted at the side of the track, they are impervious to the effects of flying ballast and the various oils and fuels associated with railway operations. Mounted on station platforms, their durability as well as their attractive appearance come into their own.

Outside in

The enclosure that the equipment is housed in provides the strongest link in the security chain

Once inside the building, the extremes of environment are no longer a consideration and contractors naturally face the temptation of installing standard, cheap metal enclosures. The electronics associated with access control equipment, for example, is usually located indoors.

Some special considerations still apply, however, if the risk of damage or tampering is to be minimised. Exposed gland plates are an area of particular vulnerability, as these can be unscrewed relatively easily, giving access to the enclosure interior. For this reason, enclosures without gland plates are often the best choice.

However tempting the use of standard sheet metal enclosures may be, these are generally unsuitable for security applications since they are inherently susceptible to tampering.

Modern security and access control systems can involve significant data processing, networking and reporting. In such arrangements, network hubs and server stations may be encountered as well as dedicated 19 inch rack mounted controls. These installations are generally in control rooms and sometimes in controlled environments.

Here again, sheet steel enclosure products are almost invariably used, but it is worth bearing in mind that not all racks are created equal. The equipment used in security applications is rarely standard and there is therefore a challenge to the installer or system builder to compromise how the equipment is housed within the cabinet.

The best racks have facilities to make cabling easy, as well as a broad range of equipment mounting options, to minimise initial build and installation times and make future modifications easy. In some applications, security features to prevent unauthorised access to the equipment mounted in the rack may also be important.

Single or multiple sourcing

An examination of the kinds of enclosures used in security and surveillance installations cannot ignore the important topic of the enclosure supplier.

Multiple sourcing of the different enclosures from a variety of suppliers is possible of course, but most contractors and installers agree it is far from ideal. Apart from the time involved in locating suitable products, there is also the need for separate orders, problems in co-ordinating deliveries and opportunities are lost for negotiating best prices from the placement of larger orders. In instances where the electrical and mechanical contractor is not a security systems expert, there is potential for knowledge gaps that can be quickly and reliably filled by an expert hardware supplier.

The best solution is therefore to choose, if possible, a single enclosure supplier. Meeting all of a project’s requirements, from the outside to the inside, requires a broad range of products plus a depth of experience in the field. Such suppliers are best equipped to provide advice and guidance on selecting the most appropriate and most cost-effective products, installation and mounting methods for every security application.