What it is and what it does
The Siemens SENTRON 3VA1463-5GF42-0DA0 is a 4-pole molded case circuit breaker (MCCB) rated at a continuous 630 A, designed for line protection in industrial power distribution. It carries a TM240 thermal-magnetic trip unit — thermal for overload, magnetic for short-circuit — and includes an undervoltage release (UVR) as standard. The interrupting ratings are serious: 187 kA at 240 V, 121 kA at 415 V and 440 V, 75.6 kA at 500 V, and 11.9 kA at 690 V. That 187 kA at 240 V means it can clear a bolted fault on a high-capacity 240 V secondary without the breaker failing or venting plasma — critical for switchboards close to large transformers.
Thermal derating — the real-world current rating
The 630 A rating holds up to 50 °C ambient. Above that, the breaker derates linearly: 618 A at 55 °C, 607 A at 60 °C, 595 A at 65 °C, and 583 A at 70 °C. If your panel internal ambient runs at 60 °C — common in a packed enclosure with other heat sources — you lose about 23 A of headroom. That 583 A at 70 °C figure is the hard ceiling; the breaker will nuisance-trip above that continuous load. Size your feeder conductors and upstream protection accordingly.
Panel fit and integration
The breaker measures 184 mm wide, 248 mm tall, and 110 mm deep. Four-pole at 184 mm means each pole takes about 46 mm of DIN-rail width — standard for this class. The 110 mm depth includes the arc chamber and line/load lugs; leave clearance for cable bending radius behind the panel door. Operating temperature range is -25 °C to 70 °C, storage from -40 °C to 80 °C. Insulation voltage is rated at 800 V, so it's suitable for 690 V line-to-line systems with margin. Maximum power loss is 195.4 W — that heat has to leave the enclosure; factor it into your thermal calculation.