The Siemens 3VM1332-5MH32-0AA0 is a SENTRON molded case circuit breaker (MCCB) rated for 320 A continuous at 40 °C, with a TM120M thermal-magnetic overcurrent release. Breaking capacity is 187 kA at 240 V, 121 kA at 415 V and 440 V, and 76 kA at 500 V — numbers that put it squarely in high-fault-duty commercial and industrial switchboards. The 800 V rated insulation voltage means it can sit on a 480 V or 600 V bus without derating the dielectric.
Thermal derating — the real continuous current
The 320 A rating holds flat from 40 °C through 50 °C. Above that it steps down: 313 A at 55 °C, 306 A at 60 °C, 299 A at 65 °C, 292 A at 70 °C.
Dimensions are 248 mm high, 138 mm wide, 110 mm deep — a standard 3-pole MCCB footprint that fits most DIN-rail or panel-mount enclosures.