400 A line protection with ETU850 trip unit
The Siemens 3VA2340-5KP32-0DC0 is a 3-pole SENTRON molded case circuit breaker rated for 400 A continuous current (at 40–50 °C) and configured for line protection. It carries the ETU850 electronic trip unit, which supports communication functions and an undervoltage release — meaning this breaker can be integrated into a monitored power distribution system where remote tripping or status feedback is required, not just a standalone overcurrent cutout.
Breaking capacity across voltage levels
Rated short-circuit breaking capacity reaches 187 kA at 240 V AC, 121 kA at 415 V and 440 V, 75.6 kA at 500 V, and 17 kA at 690 V. The 187 kA figure at 240 V is the highest in the 3VA2 family for this frame size — it handles high-fault-current points like a main service entrance or a transformer secondary where available fault current is substantial. At 690 V the 17 kA rating still covers most industrial motor-circuit faults.
Thermal derating and ambient range
The breaker holds full 400 A rating up to 50 °C ambient. Above that it derates linearly: 375 A at 55 °C, 350 A at 60 °C, 325 A at 65 °C, and 300 A at 70 °C. Operating ambient range is -25 °C to +70 °C, with storage from -40 °C to +80 °C. For a panel builder sizing this into a high-ambient enclosure — near a furnace line or a hot motor control center — the derating curve is the figure that determines whether the breaker can carry the load without nuisance tripping. Maximum power loss is 98.5 W, which factors into enclosure cooling calculations.
Dimensions and panel fit
Physical envelope: 248 mm height, 138 mm width, 110 mm depth. The width is standard for a 3-pole 3VA2 frame — it fits the same DIN-rail or screw-mount footprint as other 3VA2 breakers in this current class. The 110 mm depth means it clears most standard distribution panelboard depths; verify gland-plate clearance if the breaker is mounted near the back wall of a shallow enclosure.
Auxiliary and trip configuration
Includes 2 auxiliary switches (HQ type) and an integrated undervoltage release (UVR). The auxiliary release design is the undervoltage release. The supplied basic switch is order code 3VA2340-5KP32-0AA0, and the integrated auxiliary trip is 3VA9608-0BB25. No voltage trigger, no phase failure detection, and no ground fault monitoring are fitted on this variant. The trip indicator is not present — status is read via the communication interface or auxiliary contacts.