The Siemens SIRIUS 3RH1911-1FA22-ZW95 is an auxiliary switch block with 2 normally open and 2 normally closed contacts, wired via screw-type terminals. It snaps onto size S00 contactors and contactor relays in the SIRIUS family, adding four auxiliary poles for signal feedback or interlocking in a control panel. Rated for 10 A thermal current (Ith), the contacts carry 10 A at 24 V DC and derate across the voltage range — 6 A at 60 V, 3 A at 110 V, 1.2 A at 220 V, and 0.5 A at 440 V DC. The AC-15 rating at 690 V is 1 A, matching typical pilot-duty loads like contactor coils and solenoid valves. That 10 A thermal figure governs the maximum continuous current through any one pole; the DC switching curve matters more for actual break capability on inductive DC loads. Mechanical service life is 10 million switching cycles typical, with contact reliability of one faulty switching per 100 million operations at 17 V, 1 mA — a low-level signal rating that matters for PLC input circuits where dry switching can cause oxide buildup on standard contacts. The block is IP20 on the front, rated for a surge voltage of 6 kV, and accepts 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²) conductors with ferruled ends.
Mounts by snap-on onto any SIRUS S00 contactor or contactor relay — no tools needed, but verify the contactor's auxiliary slot accepts the 3RH1 block profile. The 36.5 mm width keeps the assembly within the S00 envelope, important for high-density DIN-rail layouts where every millimeter of space is allocated. Screw terminals are standard; strip length of 8 to 10 mm avoids whiskers under the terminal clamp.