63 A MCCB with 242 kA interrupting capacity — what that means for your panel
The Siemens SENTRON 3VA2163-6HN32-0HC0 is a 3-pole molded case circuit breaker rated for 63 A continuous current at 40 °C, with a 242 kA breaking capacity at 240 V — that's the short-circuit current it can safely interrupt without welding contacts or rupturing the case. At 415 V and 440 V it still holds 187 kA, dropping to 121 kA at 500 V and 5 kA at 690 V. For a line protection breaker, that SCCR headroom means it can sit upstream of smaller branch breakers and still clear a bolted fault without cascading failure.
ETU350 release and shunt trip — what's built in
Overcurrent protection is handled by the ETU350 electronic trip unit, which gives you adjustable long-time, short-time, instantaneous, and ground-fault curves — not a fixed thermal-magnetic. The auxiliary release is a shunt trip (STL), so you can remotely trip the breaker via a control signal. Two auxiliary switches (HQ type) are integrated for status feedback to the PLC or panel lamps. No undervoltage release or communication module on this variant.
Thermal derating and panel fit
Rated 63 A up to 50 °C ambient; above that it derates linearly to 53.55 A at 70 °C. The operating range is -25 °C to 70 °C, storage from -40 °C to 80 °C. Maximum power loss is 4 W — negligible for enclosure heat load. Dimensions are 105 mm wide, 181 mm tall, 86 mm deep, which fits standard SENTRON 3VA panel cutouts. If you're replacing an older 3VA1 frame, check the depth — this 3VA2 series is deeper than the 3VA1's 60 mm footprint.