By careful design and the right information from the outset, a correctly specified system enclosure can truly become an asset for increased productivity and profitability for the system integrator through to the end user. John Wilkins from Rittal explains

The correct system enclosure and its associated ancillaries for the application can have a huge impact on the overall performance and efficiency of a system’s operation and can significantly prolong the life of the installed equipment, save energy, lower utility costs and protect against unscheduled downtime.

One part of providing a successful design is understanding the environment in which the final overall system will be operating and what is the most suitable internal environment required by the installed equipment, along with the ability to control this, throughout the system’s life cycle.

System integrators and engineers increasingly think about the enclosure and approaches to thermal management foremost in the design process. This used to be something of an afterthought, which can create a poor and ineffective system cooling solution, which is expensive and difficult to maintain, creating the problem of excessive energy costs for the end user as well as expensive down time, due to premature component failure. Prevention should be the main concern in any successful design.

Thermal performance will form the base line for the design of any enclosure. So much of today’s selection criteria for an optimal enclosure solution centres around thermal performance and depending on the application, size, external ambient and internal heat load, can each have an impact on the design used to solve the system cooling. As equipment is becoming smaller and requires dissipation of larger heat loads, a larger portion of the design effort should be dedicated to optimising the thermal efficiency of the system.

Software calculation programmes such as Rittal Therm, for the climate control of enclosures, have been developed to eliminate the laborious calculation of the climate control requirements. An easy to use interface leads the user to the appropriate and correctly dimensioned cooling solution. This allows ultimate design for the most efficient system cooling solutions available to the market today.  Many well designed control systems are let down by the selection of the enclosure material or the surface finish, which can have a detrimental effect on its design life, maintenance and operational down time due to corrosion or material failures.

Major considerations for the enclosure material should be considered at the initial design stage and the enclosures environment will play a major part in this selection. Companies, such as Rittal, offer a wide variety of material finishes such as mild steel, 304 & 316 stainless steel, cast aluminium, sheet aluminium, polycarbonate plastics and GRP. Mild steel is suitable for the majority of applications and shows long term durability for indoor applications when finished, for example, in Rittal’s Nano three stage powder coated finish.

For the more corrosive environment such as outdoor, coastal, chemical and heavy pollution, stainless steel should be used or when clean environments are paramount, such as the manufacture of food and beverage, in hospitals or pharmaceutical production. Stainless steel can also be powder coated and it exhibits exceptional corrosion resistance whether in its raw state or powder coated, but users should be aware if the surface is contaminated with carbon steel then the enclosure can show signs of surface corrosion.

For more cost effective outdoor solutions than stainless steel, sheet aluminium can be used. This also provides a high degree of corrosion protection and is powder coated to provide a tough finish to the enclosure surface. It can also be coated with an anti-graffiti finish making it easy to remove paints and adhesive residues from posters. Sheet aluminium also provides the added advantage of being lightweight making it easier to install without the use of expensive lifting equipment into the less accessible places.

Non metallic enclosures such as plastics and GRP impregnated plastics are more suited to the smaller range of electrical enclosures. This type of enclosure provides a robust mechanical strength and electrical insulation properties. It also provides an extremely high degree of corrosion protection but can discolour under certain light conditions but without harming the material properties of the enclosure.

The sealing of an electrical enclosure is crucial as the harmful effects of both dust and moisture to sensitive equipment can cause failure and reduce reliability. Overall security has become an issue leading to increased protection for electrical enclosures, but is enough consideration given to the protection rating? The IP rating of an enclosure is dictated not only by the enclosure itself, but also by its fixing method, lid sealing and cable entries. When mounting an enclosure inside a cabinet, fixing to a machine wall, a building wall or in a vehicle, the method of attachment can either maintain or instantly downgrade the IP rating of the enclosure assembly. With the correct enclosure selected for the integrated system it is also important to understand the requirements for access and security.

Part of a well designed system considers the access for maintenance and repairs. It’s an important benefit to the end user that down time for maintenance is kept to a minimum. With a good system design, maintenance critical components and procedures are integrated into the overall system and the type of enclosure and accessories selected play a major part in the process. Selecting something as simple as a door stay to hold the door open at a set angle can make it easier for the operative to change the fan or filter, as well as for the operator working on a solid object within a designated area around the enclosure and not in front of a live open system.

In some instances access may be restricted to some parts of the system design to all but key maintenance engineers while allowing the day to day operations to be carried out by the machine operative. This can be done in a number of ways. One of the most common is by changing the lock insert used within the standard lock mechanism fitted to the enclosures that may make up the complete system suit. This could be something as simple as changing the key shape to a square or a triangle or, for a higher security level, a key that is suited to a particular end users requirements.

Modern switchgear and control components in industrial engineering are highly complex and must satisfy universal requirements. Rittal enclosures offer an extensive range of accessories to satisfy the demands for flexible solutions in industrial production processes.

Having available an extensive range of accessories for the enclosure not only provides innovative beneficial solutions but also completes a well designed system. From providing effective cable management solutions into, within or out of the system enclosure, whether at high level or at low level using the plinths for cable routing, to providing internal lighting which can be operated when opening the door for service and maintenance when in operation. All accessories have been designed and developed to make the installation, fit out or maintenance as simple, safe and as easy as possible making the enclosure a critical part of the complete system integration and a quality product that any good system designer would be proud to be associated with.