The Siemens 3VA1332-5GE42-0AA0-ZD00 is a 4-pole IEC frame 400 MCCB rated 320 A with a 55 kA Icu at 415 V — breaking capacity class M, meaning it can safely clear faults up to that level without upstream coordination failure in a 415 V distribution panel. The TM220 overload unit adjusts Ir from 224 A to 320 A; short-circuit pickup Ii is fixed at 10 x In (3200 A). The ATFM (Adjustable Thermal Fixed Magnetic) trip provides thermal overload and fixed magnetic short-circuit protection.
The nut keeper kit simplifies DC Power OEM installations — keeps the bus-bar nuts captive during assembly in Chinese OEM lines.