It combines overload (L), short-time short-circuit (So), instantaneous short-circuit (I), and integrated earth-leakage (R) protection in one device — so a single unit handles both overcurrent and ground-fault duties on a distribution feeder. Rated 100 A at 40 °C, it carries a breaking capacity of 70 kA Icu at 415 V AC (per IEC 60947-2) and 65 kA Icu at 480 V AC (per UL 60947-4-1). That 70 kA at 415 V puts it in the H breaking-capacity class — enough for most industrial main or sub-main switchboards where fault currents run high.
If your panel runs hotter, you derate — the electronic MicroLogic 4.2 includes a thermal-memory function that tracks 20 minutes of heating before and after a trip, so it won't reclose into a still-hot load. Breaking capacity varies by voltage: 100 kA at 240 V, 70 kA at 415 V, 65 kA at 440 V, down to 10 kA at 690 V. For a 480 V panel, the 65 kA Icu per UL 60947-4-1 is the number to coordinate with upstream gear. The breaker is Category A — no intentional short-time delay, so it trips fast on a hard fault, which simplifies selective coordination with downstream devices but means you need a higher-rated upstream breaker if you want zone selectivity. Integrated earth-leakage protection means the MicroLogic 4.2 senses residual current directly — no add-on module or external RCD. The OFF position uses a rotary switch marked IΔn for setting the leakage threshold. That saves panel space and wiring vs. a separate ground-fault relay.
Front connections top and bottom with a 35 mm connection pitch — standard for panel-board busbar or cable lugging. IP40 enclosure protection and IK07 impact resistance suit it for indoor switchgear; not rated for washdown.