What It Is and the Sourcing Reality
The Siemens 3RT1936-7A is a 3-pole arc chute in Size S2, designed for the SIRIUS 3RT1 contactor family. It extinguishes the arc when the main contacts open, protecting the contactor from damage and extending its service life. For a BOM freeze or a line-down replacement, the 3RT1936-7A is sourced through surplus or broker channels against an RFQ. If you're planning a new build or a panel refresh, the 3RT2 series arc chute is the direct drop-in replacement — same Size S2 footprint, same function.