630 A MCCB with 330 kA interrupting rating — what that means for your main feeder
The Siemens 3VA2463-7HN32-0DA0 is a SENTRON molded case circuit breaker rated for 630 A continuous current at 40 °C ambient, with a maximum interrupting capacity of 330 kA at 240 V AC. That 330 kA figure is the SCCR at the lowest voltage — it drops to 242 kA at 415/440 V and 187 kA at 500 V, so the real coordination study should use the voltage your transformer secondary actually runs. At 690 V it still clears 9 kA, which covers most 690 V industrial feeders. This is a 3-pole line-protection design with an undervoltage release (UVR) built in — the UVR trips the breaker when control voltage drops, which is standard for motor feeder disconnects or emergency-stop chains where you want the breaker to open on loss of pilot power. No ground-fault monitoring, no auxiliary switch, no communication module on this variant.
Thermal derating and panel integration
The 630 A rating holds at 40 °C; above that, derate linearly to 520 A at 70 °C. If this breaker sits in a non-air-conditioned switchroom or a crowded panel, use the 50 °C or 60 °C column (593 A and 557 A respectively) for your load calculation. Dimensions are 248 mm tall, 138 mm wide, 110 mm deep — standard 3-pole MCCB footprint for a 630 A frame, mounts on a DIN rail or directly to a backplate.