The Siemens 3VA1112-4GE42-0AA0-ZD00 is a 4-pole IEC frame 160 circuit breaker in breaking capacity class S, rated for 125 A continuous current with an ultimate breaking capacity (Icu) of 36 kA at 415 V AC. The TM220 thermal-magnetic trip unit provides adjustable overload protection from 88 A to 125 A (Ir) and fixed short-circuit protection at 10 × In (Ii). N conductor protection is set at 100 %, and the unit includes a nut keeper kit for DC Power OEM applications in China.
The 36 kA Icu at 415 V places this breaker in class S — suitable for downstream distribution panels where fault current levels stay under that threshold. The TM220 trip curve (thermal-magnetic, fixed magnetic) means it handles motor inrush without nuisance tripping on the thermal element, but the magnetic pickup at 10 × In (1250 A) is fixed, not adjustable. For line protection of feeders or large motor branch circuits, that's typical; for transformer primary protection, verify the inrush profile against the fixed magnetic setting. The 4-pole configuration with N conductor protection at 100 % makes this breaker appropriate for 3-phase + N systems where the neutral is fully rated and not downsized. Common in IEC distribution panels feeding mixed single-phase and three-phase loads.
Deployment context
The nut keeper kit included with this variant is specific to DC Power OEM builds in China — verify that the kit matches your enclosure's busbar or terminal arrangement before panel layout.