What the ratings mean for your panel
The Siemens SENTRON 3VA1332-6MH32-0AA0 is a 3-pole molded case circuit breaker (MCCB) rated for 320 A continuous current from 40 °C up to 50 °C — no derating needed in that band. Above 50 °C the rating steps down to 313 A at 55 °C, 306 A at 60 °C, 299 A at 65 °C, and 292 A at 70 °C. That thermal curve means the breaker holds its full 320 A in most standard panel environments; only tight enclosures pushing internal ambient past 50 °C require a down-rate check. Breaking capacity is the headline number here: 220 kA at 240 V, 154 kA at 415 V and 440 V, 121 kA at 500 V, and 17 kA at 690 V. Those are exceptionally high fault-interruption ratings for a 320 A frame — the 220 kA figure at 240 V covers high-available-fault installations like large transformer secondaries or industrial substations without needing a current-limiting fuse upstream. The 17 kA at 690 V still clears most industrial 690 V systems. The TM120M overcurrent release is a fixed thermal-magnetic design with adjustable magnetic trip — li min 2,240 A, li max 4,480 A. That gives a magnetic pickup range of 7x to 14x the 320 A frame rating, which is typical for motor-starting inrush or transformer magnetizing current without nuisance tripping. No ground-fault monitoring, no phase-failure detection, no communication — this is a straight thermal-magnetic MCCB for standard feeder or motor-circuit protection.
Panel fit and integration
Dimensions: 248 mm height, 138 mm width, 110 mm depth. The 110 mm depth is relatively shallow for a 320 A frame — it fits standard 400 mm deep enclosures with room for rear cable routing. IP40 on the front means the breaker face is protected against tools and solid objects over 1 mm; the body is not sealed against moisture, so install it in a dry indoor panel or a weatherproof enclosure. Power loss is 80.1 W maximum. In a multi-breaker lineup, that heat adds up — account for it in the enclosure thermal calculation. The design accepts an optional motor drive (Product Extension Optional Motor Drive = Yes), so remote switching or automatic transfer schemes are possible with the add-on accessory.
Lifecycle and sourcing reality
Lifecycle stage is marked as current — meaning Siemens still produces this order code, and it has not been announced for phase-out. No successor code is listed, which is consistent with an active catalog item. For a BOM freeze or a line-down replacement, this part can be specified into the panel without worrying about last-time-buy deadlines. Rated insulation voltage Ui is 800 V, and the reference code per IEC 81346-2 is Q (switching device). The operating temperature range is -25 °C to 70 °C, with storage from -40 °C to 80 °C. Those numbers confirm suitability for most industrial environments outside of extreme cold-storage or high-heat foundry applications.