SIRIUS S00 auxiliary contactor — 110 V DC coil, 10 A switching
The 3RH1422-1BF40 is a Siemens SIRIUS auxiliary contactor in frame size S00, designed for control-circuit switching in motor starter and relay logic panels. The 10 A AC-12 rating is the ceiling for general-purpose control loads; the 690 V figure shows it handles high-voltage signal isolation without derating to zero. Two instantaneous N/O contacts (no delayed or lagging switching) with a contact reliability of one incorrect operation per 100 million cycles at 17 V, 1 mA — this matters when switching low-level PLC inputs or dry-contact signals where oxide films on standard contacts cause intermittent opens.
Panel fit — 72 mm depth, screw or snap-on DIN rail
The dual-conductor terminals allow daisy-chaining control power without extra junction blocks — useful when feeding multiple auxiliary contactors from one 110 V DC rail. Shock rated 10g at 5 ms and 5g at 10 ms — sufficient for industrial panel mounting on machine frames or conveyor sections, but not for direct engine-mount applications without additional damping.
Lifecycle and compliance — active, RoHS, 6 kV surge
Rated surge voltage resistance 6 kV, pollution degree 3, which means it's designed for industrial environments where transient overvoltages from motor switching or nearby lightning are expected — no external MOV needed for basic insulation coordination. RoHS compliance date 07/01/2006, so it meets EU substance restrictions for current installations. The product extension auxiliary switch is available — meaning the contactor accepts add-on auxiliary contact blocks for field expansion without replacing the base unit. This is standard for the SIRIUS S00 platform but worth confirming if your BOM calls for more than the two built-in N/O contacts.