630 A MCCB with 440 kA breaking capacity — selectivity headroom for large distribution
The Siemens SENTRON 3VA2463-0KQ42-0AA0 is a 4-pole molded case circuit breaker rated 630 A continuous at 40 °C, built around the ETU860 electronic trip unit. The adjustable short-circuit release range of 945 A to 5 670 A (1.5× to 9× I_n) lets you tune the magnetic pickup to the feeder's inrush profile.
The continuous current rating drops from 630 A at 40 °C to 450 A at 70 °C in 30 °C steps — a 28 % reduction at the top end. The 248 × 184 × 110 mm (9.76 × 7.24 × 4.33 in) envelope fits standard SENTRON mounting patterns;
Ground-fault and N-conductor protection
Ground-fault monitoring uses summation-current sensing on L + N conductors — it detects residual current without a separate toroid. The N-conductor protection is adjustable from OFF to 20 %–100 % of I_n, which matters when the neutral is undersized relative to the phases or when you need to coordinate with downstream RCDs.