Switch cabinet

What is a switch cabinet 

A switch cabinet is an enclosure that houses electrical and electronic components used to control and regulate machines, systems or building technology. Enclosures are essential for protecting these sensitive components from external influences such as dust, moisture, mechanical damage and electromagnetic interference. They ensure that the installed systems work reliably and safely by controlling the operating conditions and enabling an orderly arrangement of the components.

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Function of a switch cabinet 

The main function of a switch cabinet is to mount and connect the various electrical and electronic components, such as contactors, relays, fuses, control units and power supply units, in an orderly and safe manner. This enables efficient control and monitoring of machines and systems. A control cabinet also provides the necessary cooling and ventilation to ensure the optimum operating environment for the components.

Materials Function of a switch cabinet 

Switch cabinets are made from various materials that are characterized by their specific properties. Metal control cabinets are usually made of sheet steel or stainless steel, which gives them high stability and good protection against mechanical influences. Plastic control cabinets are lighter and offer good insulation against electrical currents as well as corrosion resistance. The choice of material depends on the environmental conditions and the requirements of the application.

The most common materials and their advantages:

• Sheet steel: robust and resistant, suitable for most industrial applications.
• Stainless steel: Corrosion resistant and ideal for use in humid or aggressive environments.
• Plastic: Lightweight and non-conductive, often used in environments where no mechanical stress is expected.
• Aluminum: Lightweight and corrosion resistant, offering a good balance between strength and weight.

Structure of a switch cabinet 

A switch cabinet consists of several basic components: the housing, the mounting plate, the door, cable entries and the rails for fastening components. Inside are the electrical and electronic components such as fuses, contactors, relays, controls and wiring. The components are mounted on a mounting plate or in a modular system that allows flexible adaptation to different requirements. Switch cabinets often have a modular design so that they can be expanded as required.

What types of switch cabinets are there?

There are different types of switch cabinets, depending on their application and specific requirements. Floor-standing and wall-mounted control cabinets are widely used. Floor-standing control cabinets are suitable for larger installations and offer plenty of space for components. Wall-mounted control cabinets are fixed to the wall and are ideal for smaller applications or where space is limited. Special designs such as explosion-proof control cabinets for use in hazardous environments or hygienic control cabinets for the food industry are also available.

Modular switch cabinets offer flexibility and expansion options. They consist of several units that can be combined and expanded as required. This design is particularly popular in large industrial plants and in automation technology, as it enables easy adaptation and expansion of the switchgear. The modularity also facilitates maintenance and the replacement of individual components.

Correct cable entry and feed-through for switch cabinets

In switch cabinet construction, cable entry begins with the selection of the right cables and their protective devices. Cable glands are a common means of inserting cables safely and tightly into the enclosure. They ensure that no moisture or dirt can penetrate, which is particularly important in industrial environments. They also provide mechanical relief, preventing tensile forces from acting directly on the cable connections.

An essential step is the clear labeling of the cables. This not only facilitates installation, but also later maintenance work and troubleshooting. Marked cables allow technicians to work quickly and efficiently, minimizing downtime.

The arrangement of the cables also plays a major role. Cable ducts and routes are essential for this. They ensure that cables are laid neatly and tidily and prevent cable clutter, which is not only confusing but can also be dangerous. Structured routing also helps to minimize electromagnetic interference, which could impair the function of the electrical systems.

When connecting the cables to the respective components in the switch cabinet, ensure that the connection is secure and tight. Loose or improperly fastened cables can cause malfunctions or, in the worst case, lead to short circuits and fires. Screw connections should be checked regularly for tightness, as they can become loose due to vibrations or temperature fluctuations.

Ideally, cables should be routed through the control cabinet in separate routes for power and data cables. This prevents interference and ensures optimum signal quality. Sufficient ventilation of the control cabinet must also be ensured to prevent overheating. Cables should therefore be laid in such a way that air circulation is not obstructed.

Earthing a switch cabinet

The earthing of an switch cabinet is crucial for safety and protection against electric shocks. It ensures that in the event of a fault, the electrical current is safely discharged and no dangerous voltages occur. Every enclosure must be properly earthed, including both the enclosure and the components inside. Earthing rails and terminals facilitate the connection of the earthing cables and ensure a reliable and permanent connection.

Regulations and standards for switch cabinets

Numerous regulations and standards must be complied with when building control cabinets in order to ensure safety and functionality. These include international and national standards such as IEC 61439, DIN EN 61439 and VDE regulations. These standards define requirements for the design, safety, electrical equipment and testing of control cabinets. They ensure that control cabinets can be operated reliably and safely under different conditions.

Special control cabinets

Special control cabinets are specially designed for special applications or requirements. These include, for example, explosion-proof control cabinets for use in potentially explosive areas, hygienic control cabinets for the food and pharmaceutical industries or weatherproof control cabinets for outdoor use. These control cabinets must meet special requirements and are often manufactured individually according to the customer's needs. Special control cabinets offer tailor-made solutions for special areas of application and contribute to safe and efficient operational management.