Key switches with safety contacts

Key switches are used as part of a trapped key interlock system to isolate the power supply to machines and installations. Standard key switches isolate the power by turning the key which switches de safety contacts. The released key can be used as a personal safety key or as an access key to open the access point of the isolated machine.


There are two different types of key switches:


For machines/processes without run-downtime
Turning the key provides a safe signal to the safety controller, which interrupts the energy supply to the machine or installation.


For machines/processes with run-downtime (controlled access)
The key of this switch can only be turned after the magnetic coil has been energized by the safety controller.


The released key can be used as a safety key. Or this key can give access to the safeguarded machine using a door lock.


Fortress Interlocks key switches can easily be expanded with additional locking mechanisms to open multiple doors, hatches or flaps on the same machine. After turning the 1st key, the energy supply is interrupted and the keys of the additional lock mechanisms are released mechanically. Only when all keys have been returned and turned the machine or installation can be restarted.


The Fortress Interlocks CL lock mechanism which is used in all our safety key switches can be produced in 200,000 unique keycodes which are stored together with a personal laser engraving on the end-user to exclude duplicate key issuance.


A trapped key interlock system consists of a (lockable) key switch or bolt lock and one or more locks for monitoring safety devices, such as doors, hatches, flaps or shut-off valves.


Our key switches have the following (unique) features

• Easily increase the safety level of your machines.
• TüV certified to PLe (EN / ISO 13849) and SIL 3 (EN 62061).
• Versions for machines with and without run-down time.
• Available as a built-in version or in a sturdy IP66 housing.
• Modular construction makes it possible to add additional lock mechanisms.
• Available with different contact options.
• Extremely robust and suitable for the harshest industrial environments.
• Very good resistance to vibrations.
• A different version is available for use in explosive atmospheres (ATEX).
• Stainless steel versions for corrosive environments, outdoor use and the food industry.
• Robust lock mechanism with 200,000 unique key codes.
• Includes laser engraving on lock and key.
• Colour coding of lock and key optionally possible.

Please contact us for advice or a quote without obligation.