The Siemens 3RH2911-1GA04-ZX95 is a front-mounted auxiliary switch block for the SIRIUS contactor relay family. It carries four normally-closed (NC) contacts, wired via screw-type terminals, and snaps onto the front of a contactor relay without tools. This block is physically coded and fits only the 3RH2140 and 3RH2440 contactor relays per EN 50011. It does not mount on other 3RH2 frames or on the 3RT series contactors.
Each NC contact is rated for a maximum thermal current of 10 A. At 24 V the switching capacity is 6 A; at 230 V it is also 6 A, and at 400 V it drops to 3 A. For DC switching, the 24 V rating is 10 A, falling to 0.26 A at 600 V. The AC-15 rating at 690 V is 1 A, which governs the inductive load capability for solenoid and contactor coils at higher voltages.
The switch block measures 36 mm wide, 37.5 mm high, and 43.7 mm deep. Front protection class is IP20. Wire capacity accepts 2x (0.5 to 1.5 mm²) and 2x (0.75 to 2.5 mm²) with ferrule, or 2x (20 to 16 AWG) and 2x (18 to 14 AWG) for solid wire.