The overload protection is adjustable from 56 A to 80 A via the Ir dial, so you set it to match the continuous load, not the breaker frame. Short-circuit pickup Ii is fixed at 5 to 10 times In (400–800 A through the 80 A setting), which keeps it selective with downstream branch breakers on high-impedance faults.
The nut keeper kit holds the terminal nuts captive during wiring — saves time when you're torquing down lugs in a tight enclosure. The undervoltage release (UVR) coil is 24 V DC; if the control voltage drops, the breaker trips instantly, which is standard for emergency-stop or safety-shutdown circuits that need a loss-of-voltage trip. No separate shunt trip needed for that function.