The Siemens 3RH1911-1FC22-ZW95 is an auxiliary switch block with 2 normally-open and 2 normally-closed contacts, wired via screw terminals. It mounts on Size S00 contactor relays and contactors used for switching motor loads, following the DIN EN50005 actuation standard. The block adds four auxiliary contacts to the base contactor — two NO, two NC — for feedback, interlocking, or control-circuit extension. Screw termination suits panel builds where ring-tongue or fork terminals are preferred over spring-cage.
Integration note
Size S00 is the smallest frame in the Siemens 3RH2 contactor relay family. The auxiliary block clips onto the front of the relay without increasing the panel footprint — no extra DIN-rail space needed. Screw terminals accept 1 x 0.5–2.5 mm² or 2 x 0.5–1.5 mm² conductors.