The Siemens 3RF3320-2AA22 is a 1-pole solid-state contactor from the SIRIUS 3RF33 family, rated for 20 A in AC-1 duty at 40 °C. AC-1 covers resistive or slightly inductive loads — heaters, ovens, lighting banks — where the current stays sinusoidal and in-phase with voltage. The solid-state switching means zero arcing and no contact wear, so it handles frequent on/off cycles without the mechanical fatigue a conventional contactor would show. Control voltage range is 24-230 V AC/DC on the coil side, with a separate 110-230 V AC supply for the logic.
Termination and panel integration
No screw torque to verify, no periodic re-torque on thermal cycles — the spring maintains contact force. The 105 x 27 x 122 mm footprint clips onto a standard DIN rail; adjacent units share the same rail without additional spacing.