The interrupting capacity tells you where it can safely clear a fault: 187 kA at 240 V, 121 kA at 415 V, 75.6 kA at 440 V, and 17 kA at 690 V — that's the kind of muscle you need on a high-fault panelboard or a motor control center feed, not a branch breaker. The shunt trip (STL) auxiliary release lets you trip it remotely via a control signal, which is handy for emergency-stop circuits or interlocking schemes.
Thermal derating — the number that actually governs your load in a warm cabinet
At 55 °C it steps down to 19.2 A, then 18.8 A at 60 °C, 18.4 A at 65 °C, and 18 A at 70 °C.
Auxiliary contacts and trip accessories
The integrated auxiliary trip is order code 3VA9688-0BL33, which is the shunt trip coil you wire to your control voltage.