Rated current and breaking capacity — the numbers that govern fit
That 250 A rating holds flat from 40 °C through 50 °C ambient, then derates to 243 A at 55 °C, 237 A at 60 °C, 230 A at 65 °C, and 223 A at 70 °C — so in a warm panel you lose about 11 % of capacity at the top end. Breaking capacity is voltage-dependent: 187 kA at 240 V, 121 kA at 415 V, 75.6 kA at 440 V, 30 kA at 500 V, and 17 kA at 690 V.
The 140 mm width for a 4-pole frame is standard for this class; it occupies roughly the same footprint as other SENTRON 3VA fixed-thermal breakers in the 250 A range.
Undervoltage release and line protection design
That is a common requirement for motor feeders where you want automatic disconnection on loss of control power. The product design is line protection, meaning the TM240 release curve is optimized for cable and busbar protection rather than motor or generator protection.
Maximum power loss is 59.5 W at rated current. That is the heat the breaker dumps into the enclosure — factor it into your panel thermal calculation, especially if the MCCB is mounted alongside other high-current devices in a sealed cabinet.