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.
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. At 690 V the 17 kA rating still covers most industrial motor-circuit faults.
Thermal derating and ambient range
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. 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.
Physical envelope: 248 mm height, 138 mm width, 110 mm depth.
Auxiliary and trip configuration
Includes 2 auxiliary switches (HQ type) and an integrated undervoltage release (UVR). The auxiliary release design is the undervoltage release. 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.