Siemens 3RH1911-1FA31 Auxiliary Switch Block

Siemens 3RH1911-1FA31 is a front-mount auxiliary switch block for size S00 Sirius contactors, delivering three normally open (NO) and one normally closed (NC) auxiliary contacts via EN 50005 screw-terminal connections. Designed to attach to auxiliary and motor contactors, it provides additional signaling contacts for control logic in industrial automation and motor-control applications. Siemens lists the 3RH1911-1FA31 as part of its legacy 3RH family with a successor noted as 3RH2911-1HA31. Electrical endurance is up to 200,000 cycles (AC-15, 230 V) and mechanical life up to 10,000,000 cycles, with a rated insulation voltage of 690 V and a surge withstand of 6 kV; the unit uses EN 50005 terminals and is sized for front-mount installation in the S00 form factor.