What this auxiliary switch block does on a 3RT2 or 3RH2
The 3RH2911-1LA20-ZW96 is a front-mounted auxiliary switch block that adds two normally-open (NO) contacts to a Siemens 3RT2 contactor or 3RH2 contactor relay. It's the part you snap onto the front of the contactor to get extra signal feedback — typically for PLC inputs, status lamps, or interlocking circuits — without taking up another DIN slot. Rated 10 A maximum, with a 10 A rated value at 24 V, this block handles the control-circuit currents you'd expect from a SIRIUS auxiliary contact. The AC-15 rating at 690 V is 1 A, which covers most 480 V and 690 V control schemes.
Mounting and panel fit — snap-on front, not DIN-rail
This block snaps onto the front of the contactor, not onto the DIN rail. The 36 mm width matches the 3RT2/3RH2 footprint, so it doesn't add panel width — just depth. The 43.7 mm depth is the total projection from the contactor face, which matters when the enclosure door clearance is tight. Screw-type terminals accept 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²) conductors, or 2x (20 to 16) and 2x (18 to 14) AWG. No special crimp tool needed — just a standard screwdriver.
Switching capacity across voltages — where this block works
The contact ratings drop as voltage rises: 6 A at 24 V, 6 A at 125 V, 6 A at 230 V, 3 A at 400 V, and 0.26 A at 600 V. The 10 A maximum at 24 V rated value is the thermal current ceiling — derate for inductive loads per the AC-15 curve. Contact reliability is specified at 1 faulty switching per 100 million operations at 17 V, 1 mA. That means this block is trustworthy for dry-contact signals to a PLC input — it won't miss edges at low voltage and low current. Mechanical service life is 10 million switching cycles typical. For a contactor cycling once every 10 seconds, that's over 3 years of continuous operation before the block wears out.
Lifecycle and sourcing — active, no obsolescence concern
Sourced and quoted to order against your BOM quantity through independent distribution.