63 A MCCB with starter protection — what the ratings mean for fit
The Siemens SENTRON 3VA2163-7MS32-0HH0 is a 3-pole molded case circuit breaker rated for 63 A continuous current across the full 40 °C to 70 °C ambient range — no derating needed as the panel warms up. That flat thermal curve makes it a clean fit for a motor control center or enclosed panel where internal temperatures climb. The 330 kA breaking capacity at 240 V (242 kA at 415 V, 187 kA at 500 V) means it can interrupt high-fault currents without cascading upstream; the steep drop to 3.7 kA at 690 V tells you this breaker is sized for 400 V class systems, not 690 V distribution. This is a starter-protection design — the internal trip curve is shaped for motor starting inrush, so it coordinates with a contactor and overload relay downstream without nuisance tripping on start-up. The shunt trip release (STL) lets a safety circuit or remote pushbutton open the breaker independently of the overload mechanism. Two auxiliary switches plus a separate trip alarm switch (HQ) give the PLC a dedicated signal for fault events, separate from the breaker's on/off status.
Panel fit and integration
The 105 mm width and 181 mm height place it in the standard SENTRON 3VA frame footprint — it occupies three adjacent 35 mm DIN-rail slots. Depth is 86 mm (3.39 in), which clears most 120 mm deep enclosures with room for rear-connected busbars. The shunt trip and auxiliary switches are factory-installed; no field assembly of the internal accessories.