"Micon 5 Safety has a normally closed contact and a normally open contact, which are potential-free," explains Niko Maucher, Product Manager at Rafi. "Each contact can therefore be regarded as a separate channel."

Despite the two-channel contact system, the push-buttons of the Micon 5 Safety variant have the same dimensions as those of the Micon 5 series, with a base area of 5.1 mm × 6.4 mm and a height of 3.85 mm. "The potential-free NC and NO contact with a space requirement of just 6.4 mm × 5.1 mm is a unique selling point on the market," emphasizes Niko Maucher. "A non-floating changeover contact is currently the norm." The application in the direction of functional safety stems from this redundancy in the push-button: "The NC contact enables diagnostics because it always provides a signal, even if the Micon 5 Safety is not currently being actuated. This means that it can be checked at any time to ensure that the push-button is functional," explains Maucher.

Niko Maucher, Rafi: "Micon 5 Safety has a normally closed contact and a normally open contact that are potential-free."

© Rafi

The micro pushbuttons therefore enable a particularly economical and space-saving design in applications that are developed in accordance with functional safety standards such as DIN EN IEC 61508 (basic standard for functional safety), DIN EN ISO 13849 (safety-related parts of control systems), DIN EN IEC 62061 (safety of control systems), DIN EN IEC 60601 (electrical medical devices), DIN EN ISO 25119 (control systems for agriculture and forestry), DIN EN 50128 (railroad applications) or ISO 26262 (road vehicles). However, the pushbuttons do not fulfill a Safety Integrity Level (SIL) or Performance Level (PL) per se, but enable a high SIL or PL of the overall system: "There is no SIL or PL for electromechanical components - it is calculated one level or one system higher," explains Niko Maucher. "Electromechanical components nevertheless play a role in the calculation of the PL or SIL of a system, such as a control panel for agricultural machinery. This calculation is usually based on the service life or the B10 value of the electromechanical components."

Thanks to an optimized sealing system, the Micon-5 safety pushbuttons achieve protection class IP54 or IPx7 and, with a temperature resistance of -40 °C to +125 °C, meet the current requirements of the automotive industry. Otherwise, they are suitable for all kinds of applications in the fields of medicine, construction machinery, agricultural machinery, automation, road vehicles and railroads - "especially, of course, in the control panels that Rafi develops itself", as Niko Maucher explains. The pushbuttons have an SMT connection for PCB assembly and are suitable for potting, painting and nanocoating. Like the standard versions, they are characterized by a switching-safe gold contact system, concise tactility and a long service life: Depending on the design, the push-buttons, which are available for different actuating forces, guarantee up to one million switching cycles. Thanks to the identical dimensions, the extensive Micon 5 accessory range of plungers and keycaps is also available for Micon 5 Safety without restriction.