Its interrupting capacity reaches 121 kA at 240 V AC and 75.6 kA at 415/440 V, so it handles high-fault-current service entrances and industrial feeders without cascading upstream.
Breaking capacity by voltage — where this breaker holds
At 240 V the unit clears 121 kA, which covers most secondary-side transformer faults in 480/277 V distribution. At 415 V and 440 V it holds 75.6 kA, and at 500 V it still manages 52.5 kA. The drop to 7.5 kA at 690 V tells you this is a 600 V class breaker — not a 690 V main. For 690 V installations you'd step up to a higher-voltage frame.
Thermal derating — don't size by the nameplate alone
At 55 °C it derates to 375 A, at 60 °C to 350 A, and at 70 °C to 300 A.
Ground-fault and communication provisions
This MCCB includes a ground-fault monitoring version using summation current formation on the L+N conductor. The unit also has a communication function.