The Siemens SIRIUS 3RT2926-3AP31 is a mechanical latch designed to hold S0-frame contactors (3RT202, 3RT232, 3RT252 series) in the closed position without continuous coil power — it's the part that keeps a motor or load engaged through a voltage dip or during a controlled stop sequence, without drawing coil current. The latch clips onto the contactor's front via the standard S0 snap-on interface (: clip-on), so it adds 22 mm width and 84.3 mm depth to the assembly — the same footprint as the contactor itself, meaning no extra DIN-rail space beyond the contactor's own width.
Integration — panel and wiring fit
Wiring uses screw-type terminals accepting 2x (0.5 to 2.5 mm²) solid or 1x 4 mm² solid, or 2x (0.5 to 2.5 mm²) finely stranded with ferrule. For AWG, that's 2x 14 or 1x 12. The terminals are sized for the auxiliary control circuit only — the latch carries no main power contacts (: zero NO/NC auxiliary contacts).
RoHS compliance date is marked as 10/01/2009, indicating the part meets the EU RoHS directive's substance restrictions from that date forward.