What it is and what it does
The Siemens SENTRON 3VA2340-6HN32-0DA0 is a 3-pole molded case circuit breaker (MCCB) rated for 400 A continuous current at up to 50 °C, with a 242 kA interrupting capacity at 240 V and 187 kA at 415 V — numbers that tell you this breaker handles high-fault utility feeds or large motor branch circuits without cascading upstream. It uses an ETU350 electronic trip unit, so you get adjustable long-time, short-time, and instantaneous protection curves — not a fixed thermal-magnetic bimetal. That means you can coordinate selectivity downstream without swapping the breaker body. The undervoltage release (UVR) is integrated from the factory, which drops the breaker if control voltage falls below the dropout threshold — common in emergency-stop or undervoltage-protection schemes on conveyor lines or pump skids.
Ratings and what they mean for fit
Rated continuous current Iu is 400 A, and the breaker holds that rating from 40 °C up to 50 °C ambient without derating. At 55 °C it's 385 A, at 60 °C it's 370 A, at 65 °C it's 355 A, and at 70 °C it's 340 A — so if your panel runs hot near the top of the enclosure, you need to account for the drop. Interrupting capacity is 242 kA at 240 V, 187 kA at 415 V and 440 V, 121 kA at 500 V, and 40 kA at 690 V. That 242 kA at 240 V is typical for transformer secondary main breakers in large commercial or industrial services; the 40 kA at 690 V still covers most 690 V motor circuits. Rated insulation voltage Ui is 800 V, so the breaker is rated for 690 V line-to-line systems with margin on the insulation coordination. Operating temperature range is -25 °C to 70 °C; storage range is -40 °C to 80 °C.
Physical fit and panel integration
Dimensions are 110 mm deep, 138 mm wide, 248 mm tall. The 138 mm width is the standard 3-pole MCCB footprint for this class. No auxiliary contact block is included, so if you need a status feedback signal to a PLC or a remote trip indicator, you'll add one separately. The basic switch is order code 3VA2340-6HN32-0AA0, and the integrated auxiliary trip is 3VA9608-0BB25 — both are field-installable accessories. Maximum power loss is 98.5 W at rated current — that's heat that stays inside the enclosure. For a panel with multiple breakers side by side, factor that into your thermal rise calculation to avoid nuisance tripping from ambient buildup.