What this MCCB is and what the ratings mean
The Siemens 3VA2140-7HN46-0AA0 is a SENTRON 3VA2 molded case circuit breaker (MCCB) built for line protection — the main disconnect and fault interrupter on a feeder or branch circuit. It carries a continuous current rating of 40 A across the full ambient range from 40 °C to 70 °C, so no derating curve to chase when the panel runs hot. The frame is rated 480 A, meaning the physical bus and mechanism are sized for that maximum; the 40 A trip unit (ETU350 electronic overcurrent release) is what governs the actual load. Interrupting capacity is the headline: 330 kA at 240 V AC, 242 kA at 415/440 V, 187 kA at 500 V, and 3.7 kA at 690 V. That 330 kA figure at 240 V is the one that matters for high-fault utility or transformer-fed panels — it tells you this breaker can clear a bolted fault without venting or welding contacts, provided the available fault current at the line side is within that limit.
Integration and mounting
This is a 4-pole MCCB in a 140 mm wide, 181 mm tall, 86 mm deep body. It mounts via the standard 3VA2 baseplate or direct panel-mount studs — no DIN rail adapter for this frame class. The 86 mm depth means it fits a 200 mm deep enclosure with room for gland plates and rear buswork; the 140 mm width is the critical dimension for multi-breaker lineup spacing. IP40 on the front face keeps finger-probes out but expects a dry enclosure — not a washdown location.