What it is and where it fits
The Siemens 3RH2911-2HA10-ZW96 is a front-mounted auxiliary switch for the SIRIUS line, designed to snap onto 3RT2 contactors and 3RH2 contactor relays. It carries a single normally-open (1 NO) contact rated for 10 A maximum, with voltage-dependent current handling that drops to 6 A at 24 V, 1 A at 110 V, and 0.3 A at 220 V. The spring-loaded terminals accept 2x (0.5... 1.5 mm²) with ferrule or 2x (0.5... 2.5 mm²) without, so it wires into existing control circuits without special tools.
What the ratings mean for the panel
The 10 A maximum is the thermal current (Ith) — what the contacts can carry continuously in free air. For motor control circuits, the AC-15 rating at 690 V (1 A) is the one that governs: it tells you the switch can reliably make and break solenoid loads like contactor coils at that voltage. The 6 kV surge voltage resistance (rated impulse withstand) means it handles transient spikes common in industrial panels without flashover. Mechanical life of 10 million cycles and a contact reliability of 1 faulty switching per 100 million at 17 V, 1 mA give confidence for high-cycling applications like conveyor interlocks or safety circuits.
Snap-on integration with 3RT2 and 3RH2
This switch clips onto the front of 3RT2 contactors and 3RH2 contactor relays using the snap-on fastening method — no screws, no DIN rail adapter needed. The 36 mm width and 47.7 mm depth keep it within the footprint of the base device. The spring-loaded terminals face forward for easy wiring after mounting. IP20 on the front means it's protected against finger contact but not sealed against dust or moisture, so it belongs inside a panel, not out in the washdown zone.
Lifecycle and sourcing posture
The lifecycle stage is marked as current, meaning Siemens still produces this auxiliary switch as an active line item. No end-of-life notice or successor code has been issued. For procurement, this part is sourced and quoted to order through independent distribution — availability and current pricing are confirmed at quote time against an RFQ.