What belongs in a control cabinet

Everything that belongs in a control cabinet: an overview

What does a control cabinet need to contain
The structure of a switch cabinet comprises the following basic elements
What to look out for when buying an enclosure
The most important functions and features of an enclosure housing
Tips for the purchase
Conclusion: Important considerations for purchasing and equipping your control cabinet

A well-equipped control cabinet is the centrepiece of every electrical system. It ensures reliable control and safety. In this guide, you will find out which functions a control cabinet fulfils, which variants and designs are available and which components can be housed in it. Whether for industrial or smaller applications - this guide will help you get an overview of all the variables of the control cabinet and make the right decision for your purchase.

What is an enclosure?

A control cabinet is an enclosure that safely houses electrical and electronic control cabinet components such as control devices, circuit breakers and cabling. Enclosures are used in industrial plants, buildings and machines. They are used for efficient and safe control, monitoring and energy distribution. They also protect the installed elements from external influences such as dust, moisture or mechanical damage and ensure an organised arrangement of the technology. If you want to buy a switch box, you should consider the requirements for size, protection class and technical specifications in order to find a customised solution for your application

What does a control cabinet need to contain?

Various components must be housed in switch cabinets to ensure the function, control and safety of an electrical system. These components include

Power supply: Transformers, power supply units for the power supply
Protection components: circuit breakers, circuit breakers, residual current circuit breakers (RCCBs) and overvoltage protection modules to protect against overload, short circuit and electrical damage
Control components: PLCs (programmable logic controllers), relays, contactors and timing relays for the control and automation of processes
Operating and display elements: HMI panels, signal lights, buttons and switches for operation and status display
Signal and data processing: isolating amplifiers, signal converters and communication modules such as Ethernet switches or fieldbus components
Cable management: terminal strips, cable ducts, cable gland, terminals and strain reliefs for clean and safe cabling
Air conditioning and ventilation: fans, cooling units or heaters to regulate the temperature in the enclosure and ensure a stable temperature
Earthing and safety: Potential equalisation rails and protective devices to ensure electrical safety

Select these components to suit the application and the specific requirements of your system. Also ensure suitable dimensioning. Well-designed control cabinets increase the efficiency and safety of the entire system.

How is an electrical enclosure constructed?

An electrical enclosure is initially empty and provides space for housing and protecting electrical components and modules. The structure of the control cabinet is modular and variable so that it can be customised according to needs, area of application and technical requirements. A small control cabinet, which is used in building automation or for small machines, for example, usually only requires basic components such as fuses, relays, terminal strips and control units. It is often built compactly to save space and only contains the elements required for the specific application. A larger control cabinet used in industry, larger machines or complex systems, on the other hand, requires more extensive equipment. Here, more powerful power supplies, PLC systems (programmable logic controllers), frequency converters, circuit breakers, communication modules and cooling systems are used. Air conditioning is particularly important to ensure a stable temperature, as sensitive and powerful electronics are often used in industry.

The structure of a switch cabinet comprises the following basic elements:

Frame or control cabinet housing: To protect the components from dust, moisture and mechanical influences
Mounting plate: For mounting the individual components (parts) such as contactors, relays or PLC systems
Door or cover: With or without viewing window, allow access to the control unit and facilitate operation and maintenance.
Cable management: Cable ducts and terminal strips for organised cabling; also terminal blocks that enable simple and secure connection of cables
Top-hat rails: Standardised rails on which components such as automatic circuit breakers, circuit breakers, residual current circuit breakers (RCCBs), surge protection modules, relays, contactors or PLC modules are mounted, ensure proper and stable mounting of components in the control cabinet
Cable feed-through: Device for feeding cables safely and without damage into the enclosure from the outside, while also providing a secure seal against dust or moisture
Enclosure light: lighting unit inside the enclosure, enabling better visibility of components and easy maintenance in the dark or in poor lighting conditions

These basic elements ensure a functional, safe and well-organised structure of the control cabinet. They support the smooth operation of the electrical system. Thanks to the modular design, an enclosure - whether small or large - can be customised precisely to the requirements of the respective application.

What to look out for when buying an enclosure

Whether for machine control, for automation systems or for retrofitting systems - as an electronics engineer or electrical installer, you are probably regularly faced with the decision to buy or equip new control cabinets. We would therefore like to provide you with some decision-making aids:

Firstly, the size and volume of the control cabinet should be selected to suit the requirements. An enclosure that is too small could lead to space problems when installing the components, while one that is too large will take up unnecessary space and incur costs.

Another important aspect is the protection class of the electrical enclosure. Depending on the area of application, for example in industrial environments or outdoors, the protection class (e.g. IP54 or IP65) should be selected to protect the electrical enclosure from dust, moisture and other environmental influences. If you are buying an enclosure that is to be used in a damp or dusty environment, a high protection class is crucial for the longevity and functionality of the system.

If you are buying an enclosure, pay attention to its flexibility and modularity. We recommend choosing a model that can be divided into different segments and that allows components such as top-hat rails, terminal blocks or cable glands to be added or removed. This flexibility ensures that the enclosure can also be easily adapted and expanded in the future.

Criteria such as quality, reliability, costs and compliance with standards also play an important role when purchasing an enclosure. Safety aspects, such as fire protection, are particularly crucial. Switch cabinets that are intended for industrial use or in safety-critical areas must fulfil certain fire protection requirements. This is the only way to minimise the risk to employees and the system in the event of a fire. Materials such as fire-resistant paintwork, fire-resistant enclosure housings and special fire protection devices are often required. These ensure safety and comply with legal requirements. These factors can influence the price and therefore also purchasing decisions. However, they are essential for safe and reliable long-term use of the control cabinet. play an important role when purchasing a control cabinet. Safety aspects, such as fire protection, are particularly crucial. Switch cabinets that are intended for industrial use or in safety-critical areas must fulfil certain fire protection requirements. This is the only way to minimise the risk to employees and the system in the event of a fire. Materials such as fire-resistant paintwork, fire-resistant enclosure housings and special fire protection devices are often required. These ensure safety and comply with legal requirements. These factors can influence the price and therefore also purchasing decisions. However, they are essential for safe and reliable long-term use of the enclosure.

The switch cabinet spanner

An enclosure key is a versatile tool that has been specially developed to open and operate various types of enclosures, distribution boxes and technical systems. These keys are often multifunctional and combine several profiles (e.g. square, triangular or double-bit) in a single tool so that they can be used with a wide variety of locking systems. Particularly in industrial environments, for electricians or maintenance technicians, a control cabinet key is part of the basic equipment. When purchasing, it is important to ensure compatibility with existing systems and robust workmanship, as the key is often exposed to high loads in everyday working life. A compact, multifunctional switch cabinet key saves space and time - a practical helper for quick access to technology and infrastructure!

How big does an enclosure need to be?

The size of an electrical enclosure, or the dimensions of the empty enclosure, depends on the requirements of the respective application and on how many and which components need to be installed. Even a small control cabinet should be dimensioned in such a way that there is sufficient space for all components such as PLCs, contactors, fuses, terminal blocks and top-hat rails. Proper cabling must also be possible. Also check whether there is enough reserve space for later extensions. As a rule, 20 to 30 % of the interior space is sufficient for this.

The most important functions and features of an enclosure housing

The robust enclosure housing protects and organises electrical and electronic components. It is used to safely house components such as control units, relays, fuses and cabling. Enclosure housings offer protection against dust and environmental influences as well as mechanical damage, thus ensuring the safe and efficient functioning of the entire electrical system. They are available in various materials, sizes and designs to meet the specific requirements of industrial, building services or private applications. Rittal distribution enclosures extend this range thanks to their high modularity and flexibility. They are ideal for use in a wide variety of environments and offer an optimum basis for efficient and space-saving installations thanks to intelligent cable management solutions and a well thought-out interior design. In addition, the robust design and high-quality materials ensure a long service life and reliable protection, even under demanding conditions.

What materials is an enclosure made of?

Enclosure housings can be made of different materials, with each material offering specific advantages and disadvantages. It is therefore highly advisable to consider these criteria when purchasing an enclosure.

1. sheet steel

Properties: Usually galvanised or powder-coated to prevent corrosion, is known for its robustness and durability.
Advantages: High stability and resistance to mechanical stress. Good protection against electromagnetic interference (EMC protection). Suitable for indoor and outdoor applications, provided an appropriate coating is available.
Disadvantages: Sheet steel enclosure housings are relatively heavy, which makes transport and enclosure installation more difficult. If the enclosure is damaged, sheet steel tends to rust.
Product example: Hager empty steel enclosure for distribution systems

2. stainless steel

Properties: Electrical enclosures made of stainless steel are rust-free and corrosion-resistant, even without additional coating, and impress with their high-quality workmanship.
Advantages: Stainless steel makes electrical enclosures durable and resistant to moisture and chemicals. This makes them ideal for hygienically sensitive areas such as the food industry or medical applications.
Disadvantages: Stainless steel is more expensive than most other materials. Compared to plastic enclosures, the purchase costs are significantly higher.
Product example: Rittal compact enclosure made of 1.4301 (AISI 304)

3. plastic

Properties: Enclosures made of polycarbonate or glass fibre reinforced plastic (GRP) are lightweight and flexible.
Advantages: Plastic enclosures are considered lightweight, which facilitates transport and installation. They are also corrosion-resistant, ideal for damp environments and offer excellent electrical insulation. The purchase costs are also comparatively low - an important factor when buying enclosures.
Disadvantages: These enclosures have a lower mechanical load capacity and are less resistant to impact. They can become brittle at extreme temperatures. They also offer only limited EMC protection and are therefore less suitable for applications with high electromagnetic interference.
Product example: Perle industrial enclosure made of UV-resistant PC

4. aluminium

Properties: Enclosures made of light metal, often powder-coated, offer high corrosion resistance and are ideal for outdoor use.
Advantages: The material is characterised by its low weight and high stability. Aluminium enclosures are corrosion-resistant, especially with a coated surface, and offer good thermal conductivity.
Disadvantages: Aluminium enclosures are more expensive to purchase than models made of sheet steel or plastic and can be susceptible to dents or deformation under high mechanical loads.
Product example: Rittal CS Toptec aluminium enclosure

What types of control cabinets are there?

The most common control cabinet model is the free-standing control cabinet. Free-standing control cabinets are often used in industry as they offer plenty of space for accommodating installations and are easily accessible. Free-standing control cabinets are versatile and can be used for both small and large installations. They provide ample space for wiring, controls and other electrical components and are therefore the preferred choice for most standard applications. There are also wall-mounted enclosures, which are often used for smaller applications or where space is limited. In comparison, free-standing control cabinets, which stand independently on the floor, favour larger installations or an individual arrangement. Complete control cabinets and modular control cabinets are also used to fulfil more complex requirements. Some manufacturers offer almost unlimited possibilities in terms of design, which means that even the most demanding requirements can be easily realised. Rittal in particular has excelled in this area.

What needs to be considered when installing and wiring control cabinets?

Control cabinet installation requires precise planning and careful execution to ensure reliable operation. To begin with, mount the control cabinet at the intended location in accordance with the requirements. Make sure it is securely fastened and take into account all environmental influences such as moisture or dust. The next step is to mount the components on the prepared mounting plate. Components such as contactors, relays or fuses are fixed in place to ensure flexibility and organisation. At the same time, the cable management is prepared: Cable ducts and strain reliefs ensure a clean structure and facilitate subsequent maintenance work.

Important notes on control cabinet installation

Work on the control cabinet must be carried out in accordance with applicable standards (e.g. VDE, IEC). Also check that all connections on the control cabinet are de-energised before you start wiring or installing the components. This will ensure that there is no unintentional danger from power supply during work. It is also important that you carefully document any changes to the control cabinet or wiring, as this will make maintenance and subsequent retrofitting easier.

Tips for the purchase

If you want to buy an electrical enclosure, you may be faced with a number of considerations. We would like to help you with this and recommend that you research online first. Like many other commercial products, control cabinets are increasingly being purchased online, which offers numerous advantages.

Uncomplicated: Buying electrical enclosures online gives you 24/7 access to a large selection without being tied to opening hours or geographical locations.

Price comparison: You can quickly find the best offer online. Enclosures, complete enclosures and frames as well as their prices can be clearly compared.

Availability: The online shop usually gives you direct insight into the stock and current availability of the required enclosure.

Detailed product information: Descriptions and technical specifications can be called up with a click. This not only helps you when selecting and purchasing a switch box, but also for subsequent installation measures.

Customer reviews: Use reviews and experiences of other buyers to make the best choice for your business.

Customised solutions: Do you need a standing and weatherproof switch cabinet with special dimensions? Search online and find the enclosure or important contacts you need quickly. Above all, Rittal enclosures mean precise customised production that perfectly matches your specific applications and spatial conditions.
Fast delivery: It doesn't matter whether you need a small or bulky enclosure - purchased online, it is usually delivered quickly to the desired location.

Support from manufacturers: Well-known manufacturers such as Hager and Rittal in particular offer support with planning and configuration. With the help of online tutorials, videos and configuration tools, you can design the enclosure efficiently and in a space-saving manner - both the frame design and the interior layout

In pieces from stock

Terminal blocks

The unique terminal block system from Phoenix Contact gives you a choice of terminal blocks: UT screw terminal blocks and PT Push-In® terminal blocks.

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Conclusion: Important considerations for purchasing and equipping your control cabinet

Before you buy an enclosure, you should know that it is usually delivered empty and is equipped on site according to your specific requirements. You should consider factors such as the area of application, possible influences and space conditions before you buy in order to make the right choice. The decision in favour of an upright switch box or a special type depends on the available space and the requirements of your application. Make sure that the electrical control cabinet offers sufficient space for your installations and is well organised and documented. Only careful planning and professional installation will ensure the safe and long-term use of your electrical installation.