The 3VA1450-6EE32-0AA0-ZD00 is a Siemens 3VA1 IEC frame 630 molded-case circuit breaker, 3-pole, rated In=500A with a TM220 thermal-magnetic trip unit (ATFM). Overload protection is adjustable via the TM220: Ir spans 350A to 500A, so you set the long-time pickup to match the cable or load continuous rating. Short-circuit protection is fixed at Ii = 10 x In (5,000 A), which is a magnetic instantaneous trip — good for motor starting inrush or transformer energization without nuisance tripping. The suffix "nut keeper kit for DC Power OEM in China" indicates this variant includes hardware for DC-side mounting and is configured for an OEM application in China. The breaker itself is IEC-rated, so it is suited for global installations where IEC 60947-2 applies.
The TM220 trip unit is field-adjustable, so you can dial Ir without swapping the trip. For a 500A feeder, plan for cable lug size up to 300 mm² or parallel runs; the frame accepts standard busbar connections.