400 A MCCB with 187 kA interrupting — panel fit and trip coordination
The Siemens SENTRON 3VA2340-5HN42-0HH0 is a 4-pole molded case circuit breaker rated for 400 A continuous current (Iu) with a 187 kA interrupting capacity at 240 V — that's the headline number for fault-clearing duty at typical North American distribution voltages. At 415 V and 440 V it still holds 121 kA, and at 500 V it's 75.6 kA; only at 690 V does it drop to 17 kA, which is still adequate for most 690 V motor circuits. This is not a thermal-magnetic breaker — the ETU350 electronic trip unit gives you adjustable long-time, short-time, instantaneous, and ground-fault protection curves. That matters when you need selectivity with downstream breakers or want to dial in the trip threshold for a specific load profile. The breaker carries its full 400 A rating up to 50 °C ambient; above that it derates linearly to 340 A at 70 °C. Panel integration is straightforward: the 184 mm width × 248 mm height × 110 mm depth fits the standard SENTRON 3VA frame footprint. The auxiliary contact block is configured as 2 auxiliary switches plus 1 trip alarm switch (HQ version), and the shunt trip release (STL) is factory-installed — no field wiring of a separate undervoltage release needed.
Key specs at a glance
Rated insulation voltage Ui: 800 V. Maximum power loss: 96 W. Operating temperature range: -25 °C to +70 °C; storage range: -40 °C to +80 °C. Mechanical endurance: 15,000 operations (latching). Trip indicator present; voltage trigger present. No communication function, no phase failure detection, no ground fault monitoring version fitted.