What this breaker is — and what the ratings mean for your panel
The Siemens 3VA1340-6EF42-0AA0-ZD00 is a current-production IEC frame 400 molded-case circuit breaker from the 3VA1 series, built for line protection in distribution panels and OEM machinery. Its headline rating is a 70 kA Icu at 415 V — breaking capacity class H — which means it can safely interrupt a fault current up to 70 kA without welding contacts or cascading failure upstream. That matters when you're coordinating downstream breakers on a high-capacity transformer or generator feed. The TM240 ATAM trip unit delivers thermal-magnetic overload protection with an adjustable Ir range from 280 A to 400 A (the In rating), and a short-circuit pickup Ii adjustable from 5 to 10 times In. A panel engineer setting up selectivity with a 400 A feeder will dial Ir to match the load's continuous current and Ii to ride through motor inrush without nuisance tripping. The N conductor is unprotected (no neutral pole overload protection), which is standard for line-side applications where the neutral is bonded to ground and doesn't need its own trip.
Deployment context: where this breaker fits
The 3VA1 frame bolts into a standard distribution panel or switchboard — it's a fixed-mount MCCB, not a plug-in unit, so plan for bus-bar drilling and torque-specified terminations. The included nut keeper kit for DC Power OEM in China suggests this variant was configured for a specific OEM integration; verify the nut keeper thread and torque spec if you're replacing an existing unit in a panel built for that OEM.