The Siemens 3RF3330-1DA04-0KN0 is a 1-pole solid-state contactor from the SIRIUS 3RF33 family. Its headline AC-1 rating of 30 A at 40 °C means it handles resistive heating loads — heaters, ovens, lighting banks — at that current continuously. The 48-460 V load range covers common single-phase supply voltages across global installations. The 24 V DC low-power control input draws minimal current from the PLC or safety relay output, which keeps the control transformer small and the heat in the panel low. Short-circuit-proof up to 25 A with a B-curve miniature circuit breaker: that means you can size the branch protection as a B16 or B20 MCB and the contactor self-protects without a separate semiconductor fuse. For a panel builder, that saves a fuse holder and a DIN row.
Screw terminals accept standard power wiring. The 105 x 27 x 122 mm footprint fits a single 22.5 mm-wide DIN-rail position — same width as a 1-pole MCB, so it slots neatly into a lighting or heating panel without stealing extra rail space. The 24 V DC control side shares the same terminal row; no separate coil suppression diode needed because the DC input is internally protected.