The Siemens 3VA2440-5KP32-0AE0 is a 3-pole IEC frame 630 circuit breaker with a breaking capacity class M rating of Icu=55kA at 415 V. That means it can safely interrupt fault currents up to 55,000 amps without welding its contacts or blowing apart — critical for selectivity in a main or feeder panel where the upstream transformer can dump serious energy into a bolted fault.
This breaker carries an ETU850 electronic trip unit with LSI protection — long-time (overload), short-time, and instantaneous. The overload protection (Ir) is adjustable from 160 A to 400 A, matching the 400 A continuous rating (In). Short-time pickup (Isd) goes from 0.6 to 10 times In, and instantaneous pickup (Ii) from 1.5 to 15 times In. That range lets you coordinate downstream with branch breakers and still clear a hard fault fast. It also accepts an optional external current transformer for neutral conductor protection up to 160% of the phase rating.
The breaker includes a nut keeper kit and provisions for up to four HQ auxiliary switches — useful for remote status indication or interlocking in a motor control center. For a panel OEM wiring this into a 630 A frame switchboard, the auxiliary contacts save adding a separate contactor block for feedback to the PLC.