The Siemens SENTRON 3VA1332-6GE42-0AA0 is a 4-pole molded case circuit breaker rated at 320 A continuous current, designed for line protection in distribution panels. Its TM220 thermal-magnetic release handles overload and short-circuit protection without external trip units. The 220 kA breaking capacity at 240 V means it can safely interrupt high-fault currents in low-voltage mains — useful where the available fault current is well above typical 65 kA or 100 kA MCCB ratings. At 415 V it still clears 154 kA, so it holds up in 400 V industrial networks with high transformer capacity.
Thermal derating and panel fit
The breaker holds full 320 A up to 50 °C ambient. Above that it derates linearly: 313 A at 55 °C, 306 A at 60 °C, 299 A at 65 °C, 292 A at 70 °C. If the panel runs hot — say near a drive stack or in a non-climate-controlled enclosure — size the upstream conductor and bus for the derated figure, not the nameplate. The 184 mm width and 110 mm depth fit standard 4-pole MCCB mounting footprints; the 248 mm height leaves room for lug access and arc-chamber clearance. IP40 on the front keeps dust out of the mechanism in a clean panel environment.