According to the normally closed principle

The principle of the Mayser normally closed Safety Edges SL/NC is based on a chain made up of normally closed contact links integrated in a rubber profile.

When the normally closed Safety Edge is activated, an existing contact is interrupted. The principle contrasts with the normally open Safety Edge, where a contact is closed, thus triggering a signal.

Mayser normally closed Safety Edges are mounted as Anti Pinch Sensors direct to the dangerous main and secondary closing edges. When the normally closed Safety Edge is activated, the connection between the contacts is interrupted and the dangerous movement is brought to an immediate halt.

The positive break contact chain simultaneously fulfils the function of the sensor and of the evaluation unit. A special control unit is therefore not necessary. The normally closed Safety Edge is connected direct to conventional E-Stop modules or to the machine control.