The Siemens 3RF3320-1BA26 is a 1-pole solid-state contactor from the SIRIUS 3RF33 family, rated AC-15 at 12 A at 40 °C. AC-15 is the switching category for electromagnetic loads — solenoids, contactor coils, clutches — where inrush can hit 10x steady-state. The 12 A rating at 40 °C means it handles those loads continuously at typical panel ambient; derate above that. Load voltage range is 48-600 V, coil is 110-230 V AC, and switching is instantaneous — no zero-cross delay, so it fires on command for fast-acting circuits.
The 1-pole form factor saves width compared to a 3-pole block when you only need single-phase switching. Screw terminals accept standard ferruled wire; strip length and torque follow the SIRIUS 3RF33 manual. Packaging dimensions are 105 x 27 x 122 mm — fits a standard 27 mm wide slot on the rail.