The Siemens SENTRON 3VA1332-7MH32-0AA0 is a 3-pole molded case circuit breaker (MCCB) rated for 320 A continuous current, with a TM120M thermal-magnetic overcurrent release. It's designed for starter protection — meaning it handles motor inrush without nuisance tripping while still clearing faults fast. The 440 kA breaking capacity at 240 V AC means it can interrupt high-fault currents upstream of a motor branch, so you don't cascade the trip to the main breaker. At 415 V it still holds 242 kA, and at 690 V it's rated 17 kA — the SCCR headroom is substantial for most industrial panels.
Thermal derating and panel fit
The breaker holds its full 320 A rating 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, and 292 A at 70 °C. If your panel runs hot — say near a VFD bank or in a sealed enclosure — factor that derating into the load schedule. The dimensions are 248 mm high, 138 mm wide, 110 mm deep, so it fits standard MCCB panel cutouts. Front IP40 protection keeps dust out of the enclosure face.