Siemens 3RH1921-1DA11 Auxiliary Contact Block

The Siemens 3RH1921-1DA11 is a standard front-mounted auxiliary contact block from the SIRIUS 3RH2 series, designed to expand the auxiliary contacts of contactors (3RH2xxx). With 1 NO + 1 NC configuration and screw terminals, it provides reliable signaling (e.g., for PLC inputs, lamps, or interlocks) and control circuit functions in motor starters, control panels, and automation systems. The block snaps directly onto the front of the contactor without tools, maintaining a compact footprint. It is widely used in industrial applications requiring additional contacts for monitoring or sequencing, with high electrical endurance and global approvals.