What it is and what it does
The Siemens 3RH1911-1HA01-ZW97 is a SIRIUS auxiliary switch block designed for use with contactor relays and power contactors. It provides one normally-open and one normally-closed auxiliary contact, rated for a maximum of 10 A, and snaps onto a 35 mm DIN rail for panel integration. Rated 10 A at 24 V (AC-12), the switching capacity drops with voltage: 6 A at 24 V DC, 3 A at 110 V, 1.2 A at 220 V, and 0.26 A at 600 V — the load curve you need to match against your control circuit's voltage and current draw. Mechanical life is rated at 10 million switching cycles typical, with contact reliability of one faulty switching per 100 million operations at 17 V, 1 mA — a solid figure for auxiliary circuits in high-duty-cycle applications like conveyor interlocks or valve position feedback.
Mounting and wiring
Snap-on mounting onto 35 mm DIN rail. Dimensions are 36.5 mm wide, 41.5 mm deep, and 37.5 mm tall — fits the standard contactor footprint. Screw-type terminals accept 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²) with core end processing, or 2x (20 to 16) and 2x (18 to 14) AWG. IP20 protection on the front — suitable for enclosed panel use, not for washdown environments. Operating temperature range is -25 to +60 °C; storage range is -55 to +80 °C.
Lifecycle and sourcing reality
For legacy installations where a direct replacement is needed without re-engineering the panel, this part is sourced and quoted to order through independent distribution. Availability and current pricing are confirmed at quote time against an RFQ.