What this MCCB carries — and where it fits
The Siemens SENTRON 3VA2063-5KP32-0KL0 is a 3-pole molded case circuit breaker rated for 63 A continuous current at 40 °C, with an interrupting capacity of 187 kA at 240 V and 121 kA at 415 V. That 187 kA figure at 240 V means it can safely clear a fault up to that level without upstream devices needing to coordinate — useful on high-capacity transformer secondaries or busway taps where fault current is stiff. The rated insulation voltage of 800 V gives headroom for 480 V or 600 V class systems. It carries the ETU850 electronic trip unit, which provides adjustable long-time, short-time, instantaneous, and ground-fault protection curves. The communication function means it can talk to a higher-level system for metering and status — typical for a plant-floor power distribution panel where you want remote trip indication and load monitoring without a separate power meter.
Thermal derating — the real-world current
The 63 A rating holds steady from 40 °C through 50 °C. Above that, it derates: 60.6375 A at 55 °C, 58.275 A at 60 °C, 55.9125 A at 65 °C, and 53.55 A at 70 °C. If the breaker lives in a hot enclosure — say next to a drive or in a sun-baked panel — the 55 °C figure is the one to design to, not the 63 A nameplate.
Auxiliary contacts and releases
The breaker ships with 2 auxiliary switches, 1 trip alarm switch, and 1 electrical alarm switch (HQ version). That gives you four discrete signals for the PLC or DCS: breaker open/closed, trip event, and a separate electrical alarm. The shunt trip (STL) release is built in — no separate undervoltage release on this variant. The integrated auxiliary trip module is order code 3VA9688-0BL33.