Siemens 3RH2921-1DA11 Auxiliary Switch Block

Siemens 3RH2921-1DA11 is a lateral auxiliary switch block for Sirius 3RT2/SIEMENS 3RH2 contactor assemblies, delivering one normally open and one normally closed contact to monitor the main circuit. It mounts on the side of the device (lateral mounting) with screw-terminal connections; left-side terminals are 51/52 and 63/64, while right-side terminals are 31/32 and 43/44, with a current path of 1 NC and 1 NO. The block is rated for up to 10 A at up to 690/600 V, with an insulation voltage of 690 V, enclosure protection IP20, and an operating temperature range of -25 to 60 C; mechanical operating life is typically 10,000,000 cycles and electrical life (AC-15 at 230 V) typically 200,000 cycles. It is sized for SZ S0 contactors and uses screw terminals; the auxiliary switch can be mounted on the side of the contactor assembly for expanded control and feedback functionality.