The Siemens 3RH1122-1AB00-ZW98 is a SIRIUS auxiliary contactor in the S00 frame — the smallest footprint in the family, at 45 mm wide, 57.5 mm tall, and 72 mm deep. Screw terminals accept 2x 0.5–1.5 mm², 2x 0.75–2.5 mm², or 2x 4 mm² solid. Screw and snap-on mounting lets it lock onto a DIN rail or bolt directly to a panel backplate.
The 45 mm width is the critical panel-space number — it matches the S00 contactor footprint, so this auxiliary block stacks directly alongside a 3RT2 contactor of the same frame without stealing extra DIN rail. The screw-and-snap-on fastening means you can pre-wire the block on the bench then snap it onto the rail; no tools needed for the rail mount. IP20 on the front keeps fingers out but expects an enclosure — this is a panel-interior part, not a field-mounted device. Surge voltage resistance rated at 6 kV covers the transient environment of a motor control center with contactors switching inductive loads nearby. The shock resistance — 10g at 5 ms and 5g at 10 ms — means it survives the shake of a turbine nacelle or a conveyor line without the contacts chattering. That matters when the auxiliary contacts feed a PLC input rather than a power circuit.
Compliance documentation
The part carries a substance-prohibition date of 07/01/2006, which aligns with the RoHS directive effective date. Expect a RoHS declaration of conformity from Siemens for this order code. The surge voltage rating at 6 kV implies IEC 60947-1 overvoltage category III compliance for the auxiliary contact circuit.