When sourcing DC MCCBs, you must prioritize the Rated Operational Voltage (Ue), which can reach up to 1500V DC in solar PV systems, and the Rated Current (In). Unlike AC breakers, DC breakers must handle unidirectional current flow and extinguish arcs more aggressively. Ensure the Ultimate Short-Circuit Breaking Capacity (Icu) meets your system's potential fault levels. Additionally, verify the number of poles (2P, 3P, 4P), as series connection of poles is often required to achieve higher voltage ratings.