What this 400 A MCCB delivers — and where the ratings matter
The Siemens SENTRON 3VA2440-5HL32-0KA0 is a 3-pole molded case circuit breaker (MCCB) rated for line protection, built to handle 400 A continuously across the full ambient range from 40 °C through 70 °C — no derating needed up to the top end. That makes it a solid pick for a main feeder or a large motor branch where the panel runs hot and you don't want to oversize the frame just to hold rating at elevated temps. Breaking capacity is the headline here: 187 kA at 240 VAC, 121 kA at 415 V and 440 V, 75.6 kA at 500 V, and 9 kA at 690 V. That 187 kA at 240 V means it can safely interrupt a fault current that high without welding contacts or venting arc gas into the panel — critical for high-capacity transformer secondaries or busway feeds where the available fault current is massive. The 9 kA at 690 V is the weak link; if your system runs at 690 V, this breaker is for moderate-fault locations only. It carries a shunt trip release (STL) for remote tripping — no undervoltage release, no ground-fault monitoring module. The trip indicator is absent, so you won't get a visual flag on the breaker face after a trip; plan for that in your troubleshooting workflow. Communication function is not built in, so this is a standalone breaker, not a networked power distribution unit. Power loss is 63.5 W maximum at rated load — a number to factor into your panel thermal budget, especially if you're packing several breakers in a tight enclosure. Mounting dimensions are 248 mm height, 138 mm width, 110 mm depth; it fits standard SENTRON 3VA panel cutouts and busbar systems.
Where it goes in the panel
This MCCB is designed for DIN-rail or direct-mount installation inside a distribution panel or motor control center. The 3-pole format with 400 A continuous rating makes it a natural main breaker for a 400 A sub-distribution board or a large feeder protecting a bank of smaller branch breakers. The shunt trip release lets you wire in an emergency-stop or remote-trip pushbutton — common in safety circuits for conveyors, pumps, or production lines where you need to kill power from a central location. Operating temperature range is -25 °C to 70 °C; storage range is -40 °C to 80 °C. That covers most indoor industrial environments, including unheated warehouses and hot mezzanines near ovens or furnaces. The 5 kA short-time withstand (limited to 1 second) matters for selective coordination downstream — you can set the trip curve so a branch breaker clears a fault before this main trips, keeping the rest of the plant online.