MCCB for motor and feeder protection — 50 A, 3-pole, TM120M release
Breaking capacity is the headline here: 220 kA at 240 V AC, 154 kA at 415 V, 121 kA at 440 V, and still 7.5 kA at 500 V and 690 V.
Thermal derating — what 50 A means at panel ambient
At 55 °C it derates to 49 A, at 60 °C to 48 A, at 65 °C to 46 A, and at 70 °C to 45 A. For a panel that runs warm — say 55 °C inside the enclosure — the breaker is good for 49 A continuous, not the full 50 A. If your motor FLA is 48 A and the panel ambient hits 65 °C, this breaker is marginal; step up to the next frame or improve ventilation.
The 76.2 mm width (3 in) is the standard 3-pole MCCB footprint for this frame size — it occupies three 25.4 mm module positions on a DIN rail or mounts directly to a backplate via the screw terminals. The 70 mm depth leaves clearance for wiring gutters in a typical 200 mm deep enclosure.