What the ratings mean for fit
The Siemens 3VA1050-4ED42-0AA0-ZD00 is a 4-pole IEC frame 100 circuit breaker with a 50 A fixed thermal-magnetic trip (TM210, FTFM) and a breaking capacity of 36 kA at 415 V AC — class S in the 3VA1 line. The 36 kA Icu at 415 V means it can safely interrupt a fault current up to that level without welding contacts or cascading failure upstream, which is the figure a panel builder checks against the available fault current at the distribution board. The fixed Ir=50 A and Ii=10 x In (500 A short-circuit pickup) suit it for dedicated feeder or branch protection where no field-adjustable overload is needed.
Deployment context
This breaker mounts on a DIN rail inside an IEC enclosure — the 3VA1 frame footprint is standard for panel integration. The nut keeper kit for DC Power OEM in China indicates it ships with hardware for captive nut retention, which simplifies assembly in OEM builds where the breaker is installed into a pre-punched gland plate.