What this 400 A MCCB is and what the ratings mean for fit
The Siemens SENTRON 3VM1340-5ED32-0AA0 is a 3-pole molded case circuit breaker (MCCB) designed for line protection in distribution panels. Its continuous current rating holds 400 A from 40 °C up to 50 °C, then derates gradually to 367 A at 70 °C — so if your panel ambient runs hot, the 400 A nameplate only applies up to 50 °C; above that you lose 8–33 A per step. The TM210 thermal-magnetic release gives fixed thermal and magnetic trip thresholds, no electronic adjustment. Breaking capacity hits 187 kA at 240 V AC and 121 kA at 415/440 V AC, which means it can interrupt fault currents up to those levels without upstream cascading — important for high-fault installations like industrial mains or transformer secondaries.
Sourcing and lifecycle — still current, quoted to order
The lifecycle stage is marked current, so this is still an active catalog number from Siemens — no end-of-life notice, no last-time-buy window. For a BOM freeze or a line-down replacement, it's available through independent distribution channels; availability and current pricing are confirmed at quote time against an RFQ. No official successor exists because none is needed.
Panel integration — footprint and mounting
The 3VM1340-5ED32-0AA0 measures 138 mm wide, 248 mm high, and 110 mm deep — a standard MCCB footprint for this current class. Front IP40 protection means it's suited for enclosed panel mounting where no water jets or dust ingress are expected. Rated insulation voltage is 800 V, and the maximum operating voltage is 690 V AC, so it fits 400/480 V distribution without extra derating on the insulation side. Power loss at full load is 92 W — plan for that heat in the enclosure's thermal calculation.