What the ratings mean for fit
The Siemens 3VA2450-6KP32-0DA0 is a 3-pole IEC frame 630 molded-case circuit breaker with class H breaking capacity — Icu of 85 kA at 415 V AC. That rating means it safely interrupts fault currents up to 85 kA without upstream cascading, sized for high-fault utility feeds or transformer secondaries in industrial distribution. The ETU850 electronic trip unit provides LSI protection: long-time (Ir) adjustable 200–500 A for cable/transformer overload, short-time (Isd) 0.6–10× In for selective coordination, and instantaneous (Ii) 1.5–14× In for bolted faults. The built-in undervoltage release (208–230 V AC 50/60 Hz) drops the breaker on loss of control voltage — common on safety-disconnect or emergency-stop circuits.