Trapped-Key-Interlocking Systems

To protect the operator, hazardous machines and systems are often equipped with protective barriers and gates.

In addition to using this type of so-called separating protective devices, it is essential to prevent the triggering of a potentially dangerous machine function under specified conditions to ensure the safety of the operating personnel.

This means that the dangerous machine or system must be stopped if the safety door is not closed and locked.

What is a trapped-key interlocking system?

It is a locked-key locking system, also known as a key transfer system, which consists of at least two components and is intended to prevent the execution of dangerous machine functions under predefined conditions.

At the heart of the system is an individually coded key that is automatically transferred between the components of a key transfer system. This key transfer typically takes place between a machine's extinguishing system and a so-called guard locking device, which is used, for example, to open or lock the maintenance cover of that machine.

Any function of the hazardous machine must remain completely disabled or stopped as long as the safety door is not closed and locked.