The Siemens 3RH2911-2XA31-0MA0 is a front-mounted auxiliary switch block for the SIRIUS 3RT2 contactor and 3RH2 contactor relay family. It provides 3 normally-open and 1 normally-closed contact path, wired via spring-loaded terminals — no screw torque, no re-tightening on a vibration-prone panel. It snaps onto the front of the contactor or relay without tools, occupying 36 mm width and adding 47.7 mm depth to the assembly. The IP20 front protection is standard for enclosed panel gear; the open side is covered by the host device.
Current-carrying capability by voltage and duty
The contacts are rated for a maximum of 10 A. The actual continuous current depends on the circuit voltage: at 24 V it carries 10 A (resistive) or 6 A (AC-15 inductive); at 230 V the AC-15 rating is 6 A; at 400 V it drops to 3 A. For DC switching the ratings are lower — 6 A at 24 V, 2 A at 60 V, 1 A at 110 V, 0.3 A at 220 V — reflecting the arc-extinction challenge on DC loads. The AC-15 rating at 690 V is 1 A, which covers control-circuit switching in 690 V line-fed panels. The insulation voltage is 690 V at pollution degree 3, and the rated surge withstand is 6 kV — coordination class for industrial environments with moderate transient exposure.
Contact reliability and mechanical endurance
Spring-loaded terminals accept 2 x 0.5 to 1.5 mm² with ferruled ends, or 2 x 0.5 to 2.5 mm² solid/stranded without ferrules. AWG equivalent is 2 x 20 to 14. The cage clamp holds firmly — no periodic re-torque needed on a line subject to thermal cycling.