630 A MCCB with ETU350 — what the ratings mean for fit
The Siemens 3VA2463-7HN32-0HC0 is a SENTRON molded case circuit breaker (MCCB) rated for 630 A continuous current at 40 °C, with a 3-pole configuration and an ETU350 electronic trip unit. That 630 A figure is the Iu — the uninterrupted current it carries in open air at 40 °C ambient; if your panel runs hotter, the thermal derating curve drops it to 520 A at 70 °C, so the real-world ampacity depends on enclosure conditions. The breaking capacity hits 330 kA at 240 V and still holds 242 kA at 415/440 V, which puts it in the high-interrupting class for large distribution or industrial main feeders where fault currents are severe. The ETU350 release provides adjustable long-time, short-time, instantaneous, and ground-fault protection curves — it is a fully electronic trip, not a thermal-magnetic, so coordination studies and selective tripping are practical downstream. The shunt trip (STL) auxiliary release allows remote tripping via a control signal, and the two HQ auxiliary switches give status feedback to a PLC or annunciator panel. Rated insulation voltage is 800 V, and the maximum power loss is 162 W — that heat has to be vented in a closed panel; plan for forced cooling or generous cabinet volume if the breaker is continuously loaded near its rating.
Panel integration — footprint and wiring
The breaker measures 110 mm deep by 138 mm wide by 248 mm tall. That 138 mm width is the standard 3-pole MCCB footprint for this current class — it fits the same DIN-rail or panel-mount cutout as other SENTRON 3VA2 frames in the 630 A range. The 110 mm depth matters for shallow enclosures; verify gland-plate clearance before committing the back panel. Latching endurance is rated at 15 000 cycles — that is the mechanical life for the switching mechanism, not the electrical endurance under load. For frequent switching applications (like capacitor bank or welding control), check the electrical endurance curve in the full datasheet against your duty cycle.
What the auxiliary contacts and releases add
The 3VA2463-7HN32-0HC0 ships with two HQ auxiliary switches (form C contacts) and a shunt trip release (STL). The HQ designation means high-quantity or high-reliability contact blocks — they are rated for the breaker's auxiliary circuit and provide status to a control system. The shunt trip allows a remote pushbutton, PLC output, or safety relay to open the breaker without a manual handle operation. There is no undervoltage release on this variant, and no communication module or phase-failure detection built in.