A safety switch is more than just a simple switch. It is a protective mechanism designed to save lives and prevent accidents. Whether you are aware of it or not, the special position switches (safety limit switches / safety position switches) play a crucial role in our daily lives and in every industry. Rapidly advancing automation means that more and more workpieces and machines are in motion without having to be controlled manually.

Nevertheless, it can always happen that people have to work on automation systems, for example for maintenance and repair, or enter areas where machines and devices work autonomously. If a person opens the safety door to such an area, or a protective bonnet or cover on a machine, whether due to an emergency or for routine maintenance and operation, the machines must be stopped reliably, safely and accurately. By the way, this does not only work with entire plants and machines. With the help of modern magnetic sensors, the positions of individual moving and potentially dangerous machine parts are also detected and, if necessary, stopped as soon as they have reached an individually defined end position. The signal can be transmitted in different ways, i.e. electrically, hydraulically, mechanically or pneumatically. With our safety limit switches, we rely on electromagnetic transmission.

And that’s not all. Likewise, limit switches can be used to control and monitor safety doors, on the one hand to prevent unauthorised access, for example with the help of RFID coding, and on the other hand to reliably measure when a safety door has been opened, for example by monitoring the position of a door handle to stop the machines in the safety area at the same moment.

We supply all components for the safe, simple and low-maintenance installation of safety limit switches. From individual sensors and safety hinges, to special door handles, to entire switches, pull-wire switches and magnetic switches with a separate trigger.

• Class II materials according to IEC 536: Doubling of the functional insulation to prevent electric shocks
• With positive break (snap action or slow action)
• Electrically separated contacts with contact blocks in dependent action and positive opening of the NC contacts
• Precision of the shift position
• Insensitivity to electromagnetic interference
• Use on sliding or rotating guards (covers, enclosures, doors, grilles, etc.)
• Optional RFID coding for reliable access control

These specific features make the limit switches ideal for monitoring and protecting industrial machines without inertia, where the downtime is less than the access time to the hazardous area. They thus contribute to the protection of persons working on dangerous machines by opening the control circuit. Pulling out the small latch (key) when opening the movable guard causes the machine drive to stop immediately.

The plastic series small latch (key) safety limit switches are made of glass-fibre reinforced UL-V0 and offer double insulation and a degree of protection of IP65.

The metal series safety limit switches are made of painted zamak and have IP66 protection.

All models are equipped with contact blocks 1NO+1NC, 2NC, 1NO+2NC, 2NO+1NC or 3NC with positive opening.

They comply with the requirements of the European directives (Low Voltage Directive and Machinery Directive) and meet all corresponding European and international standards.

International specifications:

• The International Electrotechnical Commission (IEC), which is part of the International
• standards organisation ISO, publishes IEC publications that serve as the basis for the
• serve for the world market.

European specifications:

• The European Committee for Electrotechnical Standardisation (CENELEC) publishes the EN
• Standards for industrial low-voltage equipment.
• These European standards differ only slightly from the international IEC standards and use a similar numbering system. The same applies to the national standards. Conflicting national standards are withdrawn.

Harmonised European specifications:

• The European Committees for Standardisation (CEN and CENELEC) publish EN standards for the safety of machinery.tions:

specifications in Canada and the USA:

• These are equivalent, but differ significantly from the IEC, UTE, VDE and BS specifications.
• UL: Unterwriters Laboratories (USA)
• CSA: Canadian Standards Association (Canada)

Note on the label issued by UL (USA):

Two levels of recognition of equipment are distinguished.

Sign	Explanation
	„Recognized“: Approved for installation in a unit if the unit in question has been fully assembled and wired by qualified personnel. They are not valid for use as “general purpose products” as their possibilities are limited.
	„Listed“: Approved for installation in equipment and as a “general purpose product” also for separate sale as a component in the USA.

European Directives:

The guarantee of the free movement of goods within the European Community presupposes the elimination of differences in the laws of the Member States. The European directives lay down common rules that are incorporated into the legislation of each state, while contradictory rules are repealed.

There are three main guidelines:

• Low Voltage Directive 2014/35/UE on electrical equipment from 50 to 1000 V alternating current and from 75 to 1500 V direct current. It specifies that the requirements set out therein are met if the equipment complies with the standards harmonised at European level: EN 60947-1 and EN-60947-5-1 for limit switches.
• Machinery Directive – 2006/42/CE: the main health and safety requirements for the design and manufacture of machinery and other equipment in the European Union, including safety components.
• Electromagnetic Compatibility Directive 2014/30/UE for all electrical equipment that may cause electromagnetic interference.

CE marking:

The CE marking must not be confused with a quality mark. It is proof of the conformity of the respective product with the European regulations. Thus, it is part of an administrative procedure and guarantees the free movement of the product within the European Community.

Standards:

• International standards:
  • IEC 60947-1 Low-voltage switchgear and controlgear – Part 1: General rules (CEI EN 60947-1).
  • IEC 60947-5-1 Low-voltage switchgear and controlgear – Part 5: Control circuit devices and switching elements – Section 1: Electromechanical control circuit devices (CEI EN 60947-5-1) – Chapter 3: Particular requirements for control circuit devices with positive break function.
  • IEC 60204-1 Electrical equipment of industrial machines – Part 1: General requirements (CEI EN 60204-1).
  • IEC 60204-2 Electrical equipment of industrial machines – Part 2: Designation of items and examples for drawings, diagrams, tables and instructions.
  • IEC 60529 Protection classes of enclosures (IP code) (CEI EN 60529).

• European standards:
  • EN 50041 Low voltage switchgear for industrial use. Control switch Position switch 42.5 x 80. Dimensions and features.
  • EN 50047 Low voltage switchgear for industrial use. Control switch Position switch 30 x 55. Dimensions and features.
  • EN 60947-1 Low-voltage switchgear and controlgear – Part 1: General rules.
  • EN 60947-5-1 Low-voltage switchgear and controlgear – Part 5-1: Control circuit devices and switching elements – Electromechanical control circuit devices.
  • EN 60947-5-5 Low-voltage switchgear and controlgear – Part 5-5: Control circuit devices and switching elements – Electrical emergency stop device with mechanical interlock function.

• American standards:
  • UL 508 Standard for industrial control devices.
  • 2 NO. 14-13 Industrial control equipment

• Chinese standards:
• • • GB 14048.5 Low-voltage switchgear and controlgear – Part 5: Control circuit devices and switching elements.

Class II materials according to IEC 536 are an important component of the position switches. The switches therefore have double insulation to eliminate the risk of electric shock and thus make other protective measures superfluous. No conductive part of the “double insulated” material should be connected to a protective conductor.

The positive break is also an important component of a safety limit switch. A control switch with one or more interrupter contacts has a positive opening operation when the switch actuator ensures full contact opening of the NC contact.

With regard to the electrical separation of the contacts, a positive drive, without elastic elements (e.g. springs), must exist between the moving contacts and the point of the actuating element where the actuating force occurs. The positive opening operation does not affect the NC contacts.

Safety limit switches with positive opening function can be equipped either with contact elements for snap action or slow action. To use several contacts on one position switch, they must be electrically separated from each other, otherwise only one may be used.

Safety limit switches and position switches are essential components of many industrial systems. They improve the safety, efficiency and accuracy of machines and systems. Here are some additional examples that highlight the many applications of these switches:

• Production lines: A safety limit switch is often used on production lines to control the flow of products. When a product reaches the end of the line, it activates the switch that stops the belt to prevent overflow and ensure worker safety.
• Automated warehouses: In automated warehouses, position switches can be used to control the position of storage robots. They detect when a robot has reached a shelf and send a signal instructing the robot to start or stop its action (such as picking up or placing an item).
• CNC machines: In CNC (Computer Numerical Control) machines, safety limit switches can help control the position of the tool head. You can stop the head when it reaches its maximum or minimum position to prevent damage to the head or the workpiece.
• Packaging machines: In packaging machines, position switches can be used to control the position of cartons or other packaging materials. They ensure that the packaging is started in the right place to ensure precise packaging.
• Oil and gas industry: In the oil and gas industry, safety limit switches can help to control the position of valves. They can detect when a valve is fully open or closed and then send a signal to stop or start the pump, contributing to the safety and efficiency of the installation.

These examples show that position switches can be used in a wide range of industries and applications. Their ability to provide precise position information and safely control machines makes them an indispensable component of many modern technologies.

Safety limit switches play a decisive role in the function and safety of safety doors. Security doors are commonly found in industrial, commercial and even residential buildings and are used to control and secure access to specific areas. Here are some of the key functions that safety limit switches perform in relation to security doors:

• Door status monitoring: Security limit switches can monitor the status of a security door – whether it is open, closed or partially open. When the door reaches its end point (either fully open or closed), it activates the end safety switch, which sends a signal to the control system to update the status.
• Preventing overrun: Safety limit switches can help prevent overloading of the door drive mechanisms. When the door reaches its end position, the switch sends a signal that stops the motor to prevent it from continuing to run and possibly overheating or being damaged.
• Burglary protection: In some cases, safety limit switches can serve as part of a burglary protection system.overheated or damaged. If the door is forced open, the switch can send a signal to an alarm system to trigger an alarm and/or notify security.
• Safety interlock: Safety limit switches can also function in conjunction with a safety interlock. When the door is moved to the closed position, the end security switch activates an interlock that prevents the door from being opened without the correct authorisation.
• Integration into safety systems: Safety limit switches can be integrated into comprehensive safety systems. They can help monitor the status of the door and can be coordinated with other security devices such as cameras, motion sensors and access control systems.

In summary, safety limit switches play an important role in the security and control of security doors. They help to ensure door security, control access and minimise potential security threats.

Our range: Switches & Accessories From safety switches, tumblers and sensors to door handles, hinges and pull-wire switches. This allows you to tailor your security installations to your individual needs, operating procedures and access rights for employees (for example, with the help of RFID).