Auxiliary switch block for 3RH2 contactor relays
The Siemens SIRIUS 3RH2911-1GA13-ZW97 is an auxiliary switch block that mounts on the front of 3RH2 contactor relays, adding one normally-open and three normally-closed auxiliary contacts. The contact configuration follows EN 50011, with terminals marked 53/54 (NO), 61/62, 71/72, and 81/82 (NC). Rated for 10 A at 24 V, it handles the control-circuit loads typical of motor-starter and relay-logic panels. Snap-on mounting means it clips directly onto the relay without tools — no DIN-rail space consumed beyond the base relay itself. The screw-type terminals accept 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²) conductors, or the AWG equivalents 2x (20–16) and 2x (18–14).
Contact ratings and switching capability
At 24 V the contacts are rated for 10 A continuous; at 230 V AC the rating is 6 A. For DC switching the derating is steeper: 6 A at 24 V, 2 A at 60 V, 1 A at 110 V, and 0.3 A at 220 V. The AC-15 rating at 690 V is 1 A, which covers the inductive control-circuit loads on higher-voltage panels. Mechanical service life is 10 million switching cycles typical. Contact reliability is specified at one faulty switching per 100 million operations at 17 V, 1 mA — a dry-circuit rating that matters for PLC input signals where low-level switching must be consistent. Surge voltage resistance is 6 kV, and the rated insulation voltage at pollution degree 3 is 690 V AC.
Physical coding and compatibility
The switch block is physically coded, meaning it only fits contactor relays 3RH2140 and 3RH2440 — a mechanical keying prevents mounting on the wrong relay variant. Dimensions are 36 mm wide, 37.5 mm high, and 43.7 mm deep. IP20 protection on the front suits enclosed panel installation. Operating temperature range is -25 to +60 °C; storage range is -55 to +80 °C. The multi-unit packaging ships 120 pieces per pack.