Siemens AG 3RH1911-1FA40 Auxiliary Switch Block

The Siemens 3RH1911-1FA40 Auxiliary Switch Block is a top-mounted accessory that adds four normally-open auxiliary contacts to Size S00 Sirius contactors, extending signaling and control circuits without altering the main power path. It uses DIN EN 50005 screw-terminal connections (S00) and is designed for use with auxiliary and motor contactors in the Sirius family. Each of the four NO contacts is rated for 230 V AC-15 at up to 6 A, with an electrical life of up to 200,000 switching cycles and a mechanical life of up to 10,000,000 cycles, making it suitable for frequent signaling in automation applications. The block provides insulation up to 690 V and withstands surge voltages up to 6 kV, delivering reliable performance in industrial environments. The 3RH1911-1FA40 is a dedicated accessory in Siemens’ Sirius lineup, intended to be top-mounted on compatible S00-size contactors to enable compact, integrated control and monitoring of auxiliary circuits.