For many end users, an electrical enclosure is simply a box in which they store electrical components and connections, wiring and cables, machinery controls and related equipment. However, when faced with the thousands of options available on the market, it becomes apparent that choosing the right and most cost-efficient enclosure for your needs is not as simple as it seems.
Enclosures come in many different materials, shapes and sizes, all offering different specifications for different sectors and applications. Some will have a higher level of security or higher level of protection against water and dust, others will offer extra safety of external locks, easier and quicker installation and the list goes on.
Deciding upon the size of an electrical enclosure is only the first step in a complex process. Additionally, there are numerous important factors that you need to consider in order to choose the best performing enclosure for your equipment. These include everything from environmental impact such as wind, rain, risk of damage (both accidental and intentional), moving on to the less commonly thought of, but equally important, issues of pollution, chemical attack, possible electrical interference, and more.
By understanding how each different factor can affect the performance of your enclosures, you can avoid making an unsuitable selection, which will add to your costs both in the present and the future.
In this blog, we outline each factor that needs to be considered when specifying electrical enclosures, in order to ensure that they perform efficiently, safely and meet their life expectancy.
Choosing the manufacturing material of the electrical enclosure is the first and most fundamental decision you’ll need to make. This is the building block of the enclosure, and will need to be carefully picked according to the level of protection you require, as different materials are more or less robust than others. Your first choice will be deciding between plastic and metal. Following this, you’ll have a wider choice of materials where the two groups can be broken down further into aluminium, steel, stainless steel, polycarbonate, and more.
Metal enclosures tend to be used for environments that require a higher level of protection and security, and are the recommended and preferred choice for outdoor environments, such as the highways, railways and marine sectors, as well as for telecoms, broadcast and data.
The choice of material, therefore, is crucial. For example, choosing between stainless steel and carbon steel will affect not only the rating and the cost of an enclosure, but also the level of protection it provides and its lifespan.
Security tends to be a major issue when it comes to electrical enclosures, especially for those that are placed in an outside environment. Some organisations, like those in the railways sector, are likely to have major issues with vandalism and theft in certain areas. Therefore, ensuring that enclosures are adequately protected in these kind of environments is crucial.
For cabinet protection, it is recommended that you undergo the LPS 1175 Security Ratings test. The test stipulates the allowable toolset and minimum time at each security rating level to prevent forcible entry. It is up to the the end user to decide on the level of threat and exposure time before intervention arrives, and the test is intended to form part of an overall security strategy.
Forced entry is not the only thing that can affect your enclosures. When considering security, you should also be thinking about other factors such as paint finish which can provide poster and graffiti protection.
Specifying electrical enclosures for outdoor use requires consideration of the possible effects of ultraviolet light, which can cause some materials to degrade faster than if they were in an indoor environment.
These issues can be avoided by adding specialised UV protection to the material if direct exposure is unavoidable. This can significantly reduce discoloration and maintain the material’s high tensile strength, making the enclosures perfect for heavy duty applications, such as trackside and offshore.
Industry specific environment
Different industries will have different requirements and, therefore, need to pay extra attention to the finer details of specifying electrical enclosures. For example, food and beverage environments will require frequent wash downs with harsh chemicals, while oil and gas operations may require protection from salt water.
High temperatures can cause costly equipment failures and downtime. Therefore, considering the cooling of your enclosure is critical. When more than 35% of enclosure applications require cooling, traditional cooling methods, such as heat sinks and fans, are often insufficient. More robust solutions, such as chillers coupled with air-to-water heat exchangers should be considered instead.
It’s not just the the outside temperature of the cabinet that must be considered, but also the temperature inside the equipment, as well as the upper and lower temperature of the kit you’re going to host inside the cabinet.
The ingress of water has the power to rapidly damage your equipment, if the proper protections against it are not in place. The level of protection you require will depend entirely on the environment and application of the enclosure. Special care needs to be taken in flood areas where glands may need to be installed to let water out if a flood occurs, or purchase cabinets on stilts. More information about protection against water can be found in the IP ratings section further down.
Application of the enclosure
It’s crucial to select an enclosure that will match the application that it’ll be used for. For example, if the enclosure serves as an electrical drive house, it will be important for you to know if it should be modified with multiple doors, a power disconnect, or multiple panels. You will also want to know whether the enclosure needs to be populated with busbar power, or other accessories.
The internal and external dimensions of an enclosure are extremely important when developing a new piece of equipment.
Outside the enclosure
If an enclosure is being stored inside, there must be careful examination for any potential obstructions, as this could impact size. It’s often the case that facilities managers want to fit the maximum amount of equipment in the smallest amount of space for the sake of efficiency. In order to make the best decision, you must consider factors such as where the machinery will be located, aisle width, ease of access for maintenance, distance to ceilings and walls, and line of sight.
Inside the enclosure
Knowing the internal design requirements will help you modify and design your enclosure for the specific kind of equipment that will be housed in it. Pre-installation modifications can account for electrical equipment, electromagnetic compatibility or shock and vibration considerations, busbar power management, and cut-outs for fans or other climate control systems.
It’s worth mentioning here that the industry’s standard measurement system for designing the vertical usable space, or height of cabinets, is called U. 1U is equal to 1.75 inches.
Are there any ergonomic requirements that need to be met, such as swing of the door, location of the mounting panel, sidewalls, LED lighting? Make sure you’re aware of these.
The very first thing to decide is whether a modular or uni-body enclosure system would work best for your needs. This will enable you to figure out whether cut-outs for cable entries would be needed and whether they need to be done while the enclosure is standing or on its back.
The size of cable going into the enclosure will indicate the building allowance in relation to the floor and sides of the cabinet. This is important, as it can affect the cooling and heating of the cabinet, and even potentially restrict airflow.
The Ingress Progression (IP) rating is critical to helping you decide which electrical enclosure to use, as it will measure and quantify how protective the enclosure is against water and solid objects.
The two digits part of the IP rating code stand for the degree of protection against foreign bodies (first digit) and protection from moisture (second digit). A third digit may be added to indicate protection from mechanical impact damage, but this is rarely used. The higher the level of protection, the higher the number of the IP rating and the higher the purchase price. The highest IP rating is IP68, which will protect your enclosure from fine dust as well as complete, continuous submersion in water.
Knowing the amount of power that your kit will require in order to operate effectively and including this in your specification is imperative. Connection to the grid is equally important. Power, or lack or power, can impose an issue in remotely located areas where connecting to main power suppliers can be impossible or costly. As such, off-grid power solutions are applicable and advisable, as they can prove to be much more convenient and cost-efficient.
Another important, but often overlooked factor of specifying electrical enclosures is their environmental impact. To ensure that the enclosure(s) you’re choosing are environmentally friendly ensure the following things before purchasing:
- The manufacturer is using energy-efficient production process;
- There is minimum use of hazardous substances and preparation during production;
- There is minimum chemical emissions during production;
- Recycle and/or safe disposal of production waste is in place;
You need to ensure that the enclosure design allows you to easily and safely service and conduct repairs. For example, consider the enclosure’s construction for factors like removing and replacing doors and panels, ease of inside access for wiring or other necessary work, and ease of installing accessories.
Here at ICEE, for example, maintenance is part of our offering to our clients, which guarantees the same level of control and quality of service not only during the fabrication and installation process, but also throughout the life of the enclosure.
A good place to start spoecifying your electrical enclosures is choosing the correct IP rating. Download your hands-on, free ‘IP rating chart’ here >