Its 320 A rating at 40 °C and 4-pole configuration suit it for three-phase plus neutral feeders in commercial or industrial switchboards. The TM240 thermal-magnetic release provides fixed overload and short-circuit protection — no adjustment, which simplifies specification but means the trip curve is set at the factory. Breaking capacity is 121 kA at 240 V, 75.6 kA at 415 V, and 52.5 kA at 500 V. At 690 V it still interrupts 11.9 kA — enough for most low-voltage motor control centers.
The breaker holds 320 A up to 50 °C. Above that it derates linearly: 313 A at 55 °C, 306 A at 60 °C, 299 A at 65 °C, and 292 A at 70 °C. The 184 mm width and 248 mm height fit standard Siemens 3VA mounting bases; depth is 110 mm. Front IP40 means tools and fingers are protected, but the breaker is not sealed against washdown.