Siemens SENTRON 3VA1332-6EF42-0AA0 — 320 A MCCB with TM240 Release
The Siemens 3VA1332-6EF42-0AA0 is a 4-pole SENTRON molded case circuit breaker rated for 320 A uninterrupted current (Iu) at 40 °C ambient, with a TM240 thermal-magnetic overcurrent release. It carries a 220 kA breaking capacity at 240 V AC, scaling down to 154 kA at 415/440 V, 121 kA at 500 V, and 17 kA at 690 V — figures that define its fault-interruption capability for high-available-fault-current distribution panels. The TM240 release is a fixed thermal-magnetic trip unit, meaning the thermal pickup and magnetic short-circuit thresholds are factory-set and not field-adjustable. This suits applications where the load profile is stable and the coordination study is done at design time — typical for feeder protection in industrial switchboards or as a main disconnect in a panel. Rated insulation voltage (Ui) is 800 V, and the maximum DC operational voltage is 600 V, so it can serve in DC distribution systems within that limit. The front face carries IP40 protection — splash protection is not provided; the breaker is intended for indoor, dry enclosure mounting.
Sourcing & Lifecycle — Current Production, No End-of-Life Signal
Physical dimensions are 248 mm high, 184 mm wide, and 110 mm deep — a standard 4-pole MCCB footprint for the 3VA platform. Panel cutout and mounting hole pattern match other 3VA frame-size breakers, so a swap within the family does not require re-drilling the backplate.
Thermal Derating and Power Loss
The breaker holds its full 320 A rating up to 50 °C ambient. Above that, derating begins: 313 A at 55 °C, 306 A at 60 °C, 299 A at 65 °C, and 292 A at 70 °C. If the panel ambient runs hot — say, adjacent to a drive cabinet — the 55 °C derate to 313 A is the number to use for the coordination study. Maximum power loss is 80.1 W. That is the heat the breaker dissipates at full rated current — relevant for enclosure thermal calculations, especially in a sealed, non-ventilated panel.
Integration Notes — Panel Fit and Accessories
The 3VA1332-6EF42-0AA0 accepts the full SENTRON 3VA accessory range: rotary handles, shunt trips, undervoltage releases, auxiliary contacts, and a motor drive. The front IP40 rating means the breaker is not washdown-rated; it belongs in a locked, indoor enclosure. Storage temperature range is -40 °C to 80 °C; operating range is -25 °C to 70 °C. The storage minimum is the shipping and warehousing limit — the breaker can sit in an unheated warehouse in winter without damage.