Solenoid interlock with innovative operating principle

Individual coding and adjustable latching force

At first sight, Schmersal's new solenoid interlock AZM 300 is significantly different from other switchgear offered on the market. Because of the innovative interlocking system in the form of a Maltese cross, the interlock can be actuated from three sides, which provides for universal application possibilities. One and the same model can be used both on revolving door with left-hand side and right-hand side hinges and on sliding doors.

Another significant advantage of this feature is that the user does not need any additional add-on parts such as a door stop or a latching element, considering that these functions have been integrated in the interlock. This is a most desired practical feature amongst machinery and plant builders.

The AZM 300 integrates another practical function, namely the adjustable latching force, i.e. the non-safety-related interlocking function when the safety guard is unlocked. Because of this feature, the interlocking system can be smoothly adjusted to suit individual requirements.

Not only the mechanical construction of the AZM 300 is innovative; the electronics are also innovative. An integrated RFID sensor detects the identification and the coding of the actuator. This means that the user can choose three different types of coding.

In the basic version, the sensor accepts any suitable target. A second – coded – version only reacts onto an individually assigned target. The teaching procedure can be repeated an arbitrary number of times. Finally, a third variant is available, which only accepts the target that was taught upon the first activation.

In this way, the user can choose the most suitable coding variant for his application. The importance of this function in actual practice cannot be overemphasised: practical investigations and field tests show over and over again that many safety guards are being tampered with. When an individually coded solenoid interlock is used, the tampering cannot be completely excluded, though it can be at least made more difficult.

The new solenoid interlock meets the requirements of Performance Level e or Safety Integrity Level 3. It was designed, amongst other things, on the basis of specific requests formulated by customers from the packaging industry, who were looking for a universally applicable, compact solenoid interlock with coding features and adjustable latching force. Considering that there is a large overlap between the packaging and the food processing industry in the Schmersal clientele, the designers have observed the principles of the hygienic design to the greatest extent during the development of this new switchgear. Dead spaces or areas where material can deposit have been avoided and also the actuator is made up of rounded elements. In addition to that, the AZM 300 is resistant to a great deal of cleaning agents. Because of its protection class IP 69K, it is also suitable for use in hygiene-sensitive areas.