What this breaker is and what the ratings mean
The Siemens 3VA1163-4GE42-0AA0-ZD00 is a 4-pole IEC molded case circuit breaker in the 3VA1 series, built on a 160 A frame but fitted with a 63 A TM220 thermal-magnetic trip unit. The 'breaking capacity class S' rating means it can interrupt 36 kA at 415 V AC — that's the maximum fault current it can safely clear without welding contacts or rupturing the case. For a 63 A breaker, that's generous headroom; you'd typically see 25–36 kA at this frame size, so this unit is suited for high-fault-capacity panels where upstream coordination demands a stiff interrupting rating. The TM220 trip provides adjustable overload protection (Ir from 44 A to 63 A) via a rotary dial, and fixed instantaneous magnetic pickup at 10 x In (630 A). The 'ATFM' designation indicates the trip unit type — thermal-magnetic with fixed magnetic, adjustable thermal. The 100% N-conductor protection means the neutral pole is fully rated, not reduced, which matters for harmonic-rich loads or where the neutral carries near-phase current.
Deployment context
This breaker mounts on a DIN rail or panel plate in a standard distribution or motor control center enclosure. The 'nut keeper kit for DC Power OEM in China' note suggests this variant was configured for a specific OEM build — the kit retains mounting hardware during transport and installation. For a panel builder, that means the breaker ships with captive nuts for the busbar connections, saving a few minutes per unit on the assembly line.