MCCB for line protection — 50 A, 4-pole, TM240 release
Breaking capacity is 75.6 kA at 240 V, 52.5 kA at 415 V, and 32 kA at 440 V — figures that give solid SCCR headroom for most industrial and commercial panelboards fed from a transformer of typical impedance. The 70 mm depth and 101.6 mm width (4-inch standard MCCB footprint) mean it fits existing 4-pole breaker slots in SENTRON and most third-party distribution boards without re-drilling the mounting plate.
Current rating holds at 50 A from 40 °C up to 50 °C ambient, then derates linearly: 49 A at 55 °C, 48 A at 60 °C, 46 A at 65 °C, 45 A at 70 °C. If your panel internal ambient runs above 50 °C (tight enclosure, solar load, adjacent heat sources), size the upstream conductor and breaker for the derated value — the 45 A at 70 °C floor is the worst-case continuous current this breaker can carry without nuisance tripping. Maximum power loss is 14.6 W — modest for a 4-pole 50 A MCCB. In a densely packed panel, that's one less heat source to factor into the thermal budget; you can usually skip forced ventilation unless the enclosure is sealed and full of other dissipating devices.
The 75.6 kA at 240 V is the headline number for North American panels where the line-to-neutral fault current is the binding constraint; the 52.5 kA at 415 V covers European 400 V three-phase systems.