630 A MCCB with ETU560 — line protection for high-fault panels
The Siemens SENTRON 3VA2463-6JQ32-0BH0 is a 3-pole molded case circuit breaker rated for continuous 630 A at 40 °C, with a thermal derating curve that drops to 450 A at 70 °C (–). Its ETU560 electronic trip unit enables adjustable long-time, short-time, instantaneous, and ground-fault protection curves — the same trip platform used across the 3VA2 high-current frame sizes. Breaking capacity reaches 242 kA at 240 V and 187 kA at 415 V, dropping to 40 kA at 690 V (–). For a 480 V panel this lands between the 415 V and 500 V figures — expect the 121 kA rating at 500 V to bound the available fault current your utility can deliver.
Ground-fault and integration details
Ground-fault monitoring uses summation current formation on the L-conductor — the ETU560 sums the phase currents internally and trips on residual current without an external zero-sequence CT. No separate phase-failure detection is built in; the ETU’s phase-loss protection is handled through the long-time curve response to an open phase. The base switch is order code 3VA2463-6JQ32-0AA0; the integrated auxiliary trip unit is 3VA9608-0BB11. Maximum power loss is 164.5 W — account for this heat in the enclosure thermal budget, especially when multiple breakers are ganged in a closed cabinet.