The Siemens SIRIUS 3RU5156-3LB2 is a thermal overload relay sized for motor protection in the 135-160 A range, class 10 trip curve. The adjustable current response value matches the operational current rating at 1.6 A — that's the minimum setting; the actual working range is 135-160 A as noted in the description.
Size S6 is a large-frame relay — this isn't a DIN-rail snap-on unit; it's designed for screw fixing into a panel or onto a contactor assembly. The 135-160 A adjustable range covers motor full-load currents in that band, and class 10 means it will trip within 10 seconds at 7.2× Ie, which is standard for standard-duty motor starting (not for high-inertia loads that need class 20 or 30). The 8 kV surge voltage resistance tells you the insulation coordination is rated for 690 V installations with pollution degree 3 — typical for industrial panels. Operating frequency is 50/60 Hz, so it's fine for 50 Hz or 60 Hz line supplies without derating.
Integration notes
Mounting is by screw fixing — no DIN-rail clip on this frame size. The relay can be mounted directly to a SIRIUS contactor of matching frame size (S6) or used standalone with separate short-circuit protection. Ambient operating temperature range isn't explicitly listed in the spec table, but the transport/storage range of -55 to +80 °C gives a sense of the thermal envelope — expect standard industrial panel conditions (0-60 °C operating) to be fine.