What this MCCB delivers for your panel
The Siemens SENTRON 3VA2340-6JQ32-0AD0 is a 3-pole molded case circuit breaker rated for a continuous current of 400 A at ambient temperatures up to 50 °C, with no derating needed in that range. Above 50 °C, the current rating steps down: 375 A at 55 °C, 350 A at 60 °C, 325 A at 65 °C, and 300 A at 70 °C — so if your panel runs hot, size the load accordingly. The breaking capacity is substantial: 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 kind of fault-interruption headroom means this breaker can sit at the main or a high-fault subfeed without worrying about cascading failure upstream. It uses an ETU560 electronic trip unit, which gives you adjustable protection curves and communication capability — the listing confirms a communication function is present. That makes it suitable for integration into a power-monitoring or energy-management system, not just a dumb overcurrent protector. The auxiliary contact configuration is three HQ auxiliary switches, and the breaker ships with a ground-fault monitoring version set for summation current formation on the L-conductor. No undervoltage release or voltage trigger is included, so if you need those, plan for a separate module.
Mounting and integration
The breaker measures 248 mm high, 138 mm wide, and 110 mm deep. Those dimensions are standard for a 400 A frame SENTRON MCCB — it will fit existing Siemens mounting plates and busbar systems. The 3-pole block occupies a single unit width in a distribution panel. Rated insulation voltage is 800 V, so it's comfortable on 690 V systems with margin. Maximum power loss is 96 W — account for that heat in your enclosure ventilation calculation.