When sourcing ACBs, you must prioritize Rated Operational Voltage (Ue) and Rated Current (In), typically ranging from 630A to 6300A. Crucially, evaluate the Rated Ultimate Short-circuit Breaking Capacity (Icu) and Rated Service Short-circuit Breaking Capacity (Ics); for high-reliability applications, Ics should equal 100% of Icu. Additionally, ensure the unit features a Microprocessor-based Trip Unit (LSIG protection) to allow for precise adjustments of Long-time, Short-time, Instantaneous, and Ground-fault protection parameters.