It's the part that sits between the contactor and the motor, monitoring current and tripping on sustained overcurrent. The main circuit uses cage clamp terminals accepting 2x (0.5... 2.5 mm²) solid or 2x (0.5... 1.5 mm²) finely stranded with ferrule.
Mounts stand-alone on a vertical surface, rotatable ±135° and tiltable ±45° front-to-back. The 45 mm width and 92 mm height fit the S00 footprint common in Siemens motor starter assemblies. Depth is 78 mm — check clearance behind the panel door. Operating temperature range -20 to +70 °C, storage and transport -55 to +80 °C. Shock rated at 8g for 10 ms. ATEX certification (DMT 98 ATEX G 001) allows use in potentially explosive atmospheres when paired with an appropriate contactor and upstream protection. The relay itself is not an ignition source under normal operation.
Auxiliary contact note
This relay comes with 0 factory-fitted auxiliary contacts. Add a separate auxiliary switch block that clips onto the side. The side clearance required is 6 mm.