Siemens 3VA1340-7EE32-0AA0 — 400 A SENTRON MCCB with TM220 release
The Siemens 3VA1340-7EE32-0AA0 is a 3-pole SENTRON molded case circuit breaker (MCCB) rated for line-protection duty, carrying 400 A continuously at 40 °C ambient with no derating needed at that temperature. Its TM220 thermal-magnetic release provides fixed thermal and magnetic trip settings — no adjustment required on the line side for standard overcurrent and short-circuit protection. The interrupting capacity hits 440 kA at 240 V, which covers most low-voltage fault scenarios without cascading upstream breakers.
Breaking capacity and selectivity headroom
At 415 V the 3VA1340-7EE32-0AA0 still clears 242 kA, and at 690 V it holds 17 kA — so the high 240 V figure isn't a single-point peak; the breaker carries real fault-clearing capability across the voltage range. For a 400 V distribution panel, the 242 kA SCCR at 415 V gives selectivity headroom against a 100 kA available fault current without needing a current-limiting upstream device.
Current rating across ambient temperature
Rated current holds flat at 400 A from 40 °C up to 50 °C, then derates gradually: 392 A at 55 °C, 384 A at 60 °C, 376 A at 65 °C, 367 A at 70 °C. That means in a warm enclosure — say 55 °C internal — you still have 392 A continuous capacity, which is within 2% of the nominal rating. The maximum power loss is 92.1 W, which factors into enclosure ventilation sizing.
Physical fit and panel integration
Dimensions are 248 mm high, 138 mm wide, 110 mm deep. The 138 mm width is standard for a 3-pole MCCB in this class — it fits the typical DIN-rail or mounting-plate footprint without oversizing the enclosure bay. IP40 on the front means it's protected against tools and wires >1 mm, but not against water ingress; mount it inside a panel with a sealed door for washdown environments.