Its 320 A continuous current rating holds flat from 40 °C through 50 °C, then derates to 292 A at 70 °C — so in a warm enclosure you lose about 9 % of headroom. The interrupting ratings tell you where this breaker can clear a fault without welding contacts or venting arc: 121 kA at 240 V, 75.6 kA at both 415 V and 440 V, 52.5 kA at 500 V, and 11.9 kA at 690 V. That 121 kA figure at 240 V is the one that covers high-fault utility feeds or transformer secondaries; the 11.9 kA at 690 V still handles most industrial motor-circuit faults. The 3-pole construction and 800 V rated insulation voltage suit it for 3-phase systems up to 690 V line-to-line.
Mounting dimensions and panel fit
Built-in auxiliary and shunt trip options
This variant ships with three HQ auxiliary switches and a shunt trip (STL) release factory-installed. The auxiliary switches give remote status feedback — open/closed/tripped — without adding an external contact block. The shunt trip lets a safety relay or remote pushbutton force the breaker open, which is useful for emergency-stop circuits or undervoltage protection schemes. The supplied basic switch is order code 3VA13324EF320AA0.