Semiconductor relay, 1-phase 3RF2 Overall width 22.5 mm, 50 A 48-460 V / 24 V AC/DC screw terminal solid-state relay SIRIUS 3RF21 for switching resistive/inductive loads, e.g. of heaters or valves in a bottling plant. The devices are non-wearing and silent and are therefore ideal for noise-sensitive areas (offices, hospitals). They are also extremely reliable at high switching frequencies. The compact design saves space on the cooling surface. The solid-state relays can also be expanded for a wide range of applications by simply clicking on the standardized 3RF29 function modules. The devices are approved for worldwide use (e.g. IEC and UL/CSA). The solid-state relays are available as single-phase devices in two widths, or as three-phase devices. They are available for different power ratings and rated operating voltages. Designed for AC or DC operation, they are available with screw, spring-type or ring terminal lug connections. In addition to the 3RF29 function modules, control connectors and terminal covers are also available as accessories. Simple, efficient and always up to date - SIRIUS modular system.