SIRIUS 3SE5 Mechanical Position Switches Siemens SIRIUS 3SE5 Mechanical Position Switches are modern, compact, and modular in design and simple to connect. Siemens SIRIUS 3SE5 switches save time and increase flexibility when installing a whole range of switch variants. Designers can combine almost any enclosure with any operating mechanism, paying due consideration to the EN 50041 and EN 50047 standards where necessary. ASIsafe electronics are integrated into the basic enclosure. Complete units and modular designs provide a high degree of design flexibility.