Main switch from HILPRESS

Main switches are used as a central switching point to completely switch off the entire current flow in an electrical system for maintenance, repair or emergency work. When the main switch is switched off, all circuits and devices connected to the electrical system are de-energized. The main switch is therefore an elementary component of the electrical system. The exact properties and specifications of a main switch can vary depending on the application and the specific requirements, such as the external environment. Therefore, the safety regulations and standards [Anchor link to safety regulations] must be observed when selecting and installing the correct main switch.

Main switches with and without housing

At Hilpress, we differentiate between main switches with and without an enclosure. The main difference with these switches is the physical cover or protection provided by the enclosure. In addition, the switches differ in the type of application.

Main switch with enclosure

A main switch with an enclosure is normally installed in a closed enclosure or switch cabinet. The enclosure provides the main switch and the surrounding electronics with additional protection against external influences such as dust, moisture or mechanical damage. It also provides protection against accidental contact or unauthorized access to the main switch. The housing can also contribute to sound insulation to reduce noise that can occur when the main switch is operated.

Main switch without housing

A main switch without an enclosure is installed directly in an electrical system or distribution board without an additional protective cover. As it has no housing, it is more susceptible to dirt, moisture or damage. Accessing the main switch without an enclosure can be a practical solution in certain situations, but also involves a higher risk.

Areas of application for main switches

Main switches are primarily used in electrical systems to switch the power supply on or off.

Switchgear and distribution cabinets

In switchgear and distribution cabinets, main switches serve as main disconnectors. This allows the entire flow of electricity in the system to be interrupted and individual circuits or devices to be switched off without the entire system having to be disconnected from the mains.

Industrial systems

In industrial plants, factories or production facilities, main switches are used to switch off the power supply to large machines, systems and production lines. This enables maintenance work, repairs or to ensure occupational safety.

What are the most important regulations for main switches?

• There must only be ON and OFF switching.
• In addition, the OFF switch must be lockable.
• The TRIPPED circuit is not considered an additional switching position and is permissible.
• However, the isolating properties must already be guaranteed in the TRIPPED position with the main contacts open.
• The main switch does not have to be closed in the TRIPPED position.

What safety regulations and standards apply to main switches?

Safety regulations and standards vary from country to country and region to region. It is therefore advisable to familiarize yourself with the safety regulations and standards applicable at the place of use. However, there are some safety regulations and standards that are widely used internationally and are regarded as a reference in many countries:

• IEC 60947 (International Electrotechnical Commission): International standard for low-voltage switchgear and controlgear
• IEC 60947-3: Detailed requirements for main switches within IEC 60947
• DIN EN 60947: European standard for main switches, based on IEC 60947
• VDE standards: Contain norms and safety standards for electrical safety. All main switches installed in Germany must also comply with this standard

In the USA, the standards and safety regulations are regulated in the following documents:

• UL 508 (Underwriters Laboratories): Defines safety regulations for industrial control circuits and switching devices, this also includes main switches
• NEC (National Electrical Code): Requirements and regulations for electrical installation, all main switches installed in the USA must comply with this standard
• NFPA 70 (National Fire Protection Association): Contains precise requirements and regulations for electrical installations