The Siemens SIRIUS 3RA1316-8XB30-1AB0 is a reversing contactor assembly built for AC-3 motor duty: 4 kW at 400 V, carrying 9 A per pole. It's a factory-assembled unit with electrical and mechanical interlock between the two contactors, so you don't have to wire a separate interlock circuit or risk a shoot-through on direction change. The S00 frame size keeps the footprint tight at 90 mm wide by 72 mm deep, and it snaps onto standard 35 mm DIN rail per EN 50022.
This order code is a phased-out product. The manufacturer lists it as such and directs to the successor: the SIRIUS 3RA2316-8XB30-1AB0 is the preferred replacement. If you have a BOM line frozen on the 3RA1316-8XB30-1AB0, the 3RA2316-8XB30-1AB0 is the drop-in functional upgrade — same S00 frame, same AC-3 rating, same 24 V AC coil.
What the AC-3 rating means for fit
It has no built-in auxiliary contacts (0 NO, 0 NC per direction), so if your circuit needs feedback or a seal-in, you'll add an auxiliary contact block.
The S00 size is the smallest SIRIUS contactor frame — 90 mm wide, 67 mm tall, 72 mm deep — so it fits a standard 8-module-wide DIN section. No side clearance needed for heat dissipation at this current level, but leave room for wiring access to the screw terminals.