What the ratings mean for fit
The Icu=70kA at 415V tells you this breaker can safely interrupt a fault up to 70,000 amps without welding its contacts or exploding — that's the maximum it can clear once. For repeated faults you look at Ics (service breaking capacity), which is typically 50-75% of Icu on the 3VA1 platform, but that figure isn't in this record. The In=320A frame is the continuous current rating; you size the upstream cable and bus for at least that. The Ir adjustment band (224A to 320A) lets you fine-tune the overload trip to match the actual load — set it near the FLA of the downstream equipment. Ii=10 x In (3200A) is the magnetic instantaneous pickup; motors starting at 6-8x FLA won't nuisance trip, but a bolted fault will clear fast.
Panel integration notes
This is a 4-pole IEC frame 400 MCCB — it's not a DIN-rail miniature breaker. It bolts into a panel on a mounting plate, typically with busbar connections for the line side and lug or adapter kits for the load side. The nut keeper kit (included per the description) helps during assembly on a vertical panel where loose hardware is a nuisance. At 320A continuous, plan for proper ventilation or derating if the breaker is packed tight with other heat sources. The TM220 thermal element responds to ambient temperature; a hot panel shifts the trip curve, so keep the internal ambient below 40°C if you want the published ratings.