What this breaker carries
The Siemens 3VA2463-7HL42-0AB0 is a 4-pole IEC frame 630 circuit breaker with a class C breaking capacity — Icu rated at 110 kA at 415 V. That means it can safely interrupt a fault current up to 110,000 A without welding or rupturing, which is the kind of headroom you need on a high-capacity main or tie breaker in a 400 V distribution board where the transformer can dump that much energy into a bolted fault.
Trip unit and protection
The ETU320 is a LI (long-time + instantaneous) electronic trip unit. Overload protection (Ir) is adjustable from 250 A to 630 A in steps, so one breaker frame covers a 250-to-630 A feeder — you dial in the cable or bus rating. Short-circuit pickup (Ii) is adjustable from 1.5x to 9x In (945 A to 5670 A at the 630 A rating). That wide Ii range lets you coordinate with downstream breakers: set it high for selectivity with branch MCCBs, or lower to protect a transformer secondary. Neutral protection is adjustable — OFF, 50%, or 100% of the phase pickup. That matters on 4-wire systems where the neutral carries harmonics (triplen currents from VFDs or LED lighting) and needs its own overload element. The nut keeper kit keeps the lug torque from backing off under vibration; it ships with the breaker.
Auxiliaries and panel fit
Two HP auxiliary switches are factory-installed. HP is Siemens' designation for high-performance auxiliary contacts rated for control-circuit isolation (typically 10 A at 230 VAC). They report breaker open/closed and tripped status back to the PLC or annunciator panel. The 4-pole body takes up the same panel width as the 3-pole version in the 3VA2 frame — the fourth pole is the switched neutral, so the neutral is disconnected when the breaker is open, which is required for some IEC installations.