What the ratings mean for your panel
The Siemens 3VA2340-7HL32-0DC0 is a 3-pole SENTRON molded case circuit breaker (MCCB) rated for 400 A continuous current from 40 °C through 50 °C ambient — no derating needed in a typical ventilated enclosure up to that temperature. Above 50 °C the curve steps down: 385 A at 55 °C, 370 A at 60 °C, 355 A at 65 °C, and 340 A at 70 °C. The interrupting ratings are what make this part stand out: 330 kA at 240 V, 242 kA at 415 V and 440 V, 187 kA at 500 V, and 7.5 kA at 690 V. That 330 kA at 240 V means it can clear a fault at the full available short-circuit current of a large transformer secondary without the arc re-striking — critical for high-fault panels where a standard MCCB would cascade upstream. The breaker includes an undervoltage release (UVR) and two HQ auxiliary switches, factory-integrated. The UVR trips the breaker when control voltage drops below a threshold — standard for emergency-stop circuits or undervoltage protection on motor feeders. The auxiliary switches give remote status feedback (open/closed/tripped) to a PLC or indicator lamp without extra wiring.
Panel integration and footprint
Dimensions: 248 mm high, 138 mm wide, 110 mm deep. The 138 mm width is the standard 3-pole MCCB footprint for this class — it fits the same panel cutout and bus-bar spacing as other 400 A frame SENTRON breakers. The 110 mm depth leaves room for rear-connection bus bars or a cable-entry gland plate without crowding the enclosure door.
Selectivity and coordination note
With a minimum short-circuit breaking capacity of 600 A and a maximum of 4,000 A (the adjustable trip range), this breaker is designed for line protection — not motor protection. It coordinates downstream with SENTRON load centers or smaller MCCBs; the 330 kA at 240 V gives full selectivity with upstream fuses or a main breaker rated below that level. For a 400 A feeder on a 2,000 kVA transformer, this holds the fault without upstream trip.