What this part is and what it does
The Siemens 3RH1911-1MA11-ZW97 is an auxiliary switch block carrying one normally-open and one normally-closed contact (1NO+1NC). It mounts on SIRIUS contactors and motor starters to provide status feedback or control interlocking signals back to the PLC or relay logic.
Integration note
This auxiliary switch block snaps onto the front of SIRIUS 3RT2 contactors or 3RA2 reversing assemblies. The 1NO+1NC configuration occupies the first auxiliary slot; additional blocks stack to the right without increasing panel depth.