What the part is, and what the line is doing
The 1SAZ431201R1002: Solid-state units like this replace the bimetallic strip in older thermal overloads: no heater windings to drift, no mechanical creep, and the trip class is set in firmware rather than by swapping a heater pack. That is the whole reason the category exists alongside the electromechanical relays — same panel footprint, finer control over the motor's thermal model.