The Siemens 3VA1112-4GF42-0AA0-ZD00 is a 4-pole IEC frame 160 circuit breaker from the 3VA1 series, rated at 125 A with a breaking capacity of 36 kA at 415 V (class S). It is configured for line protection with a TM240 thermal-magnetic trip unit, ATAM (adjustable thermal, adjustable magnetic) overload protection set from 88 A to 125 A, and short-circuit protection adjustable from 5 to 10 times In. The N conductor is fully protected (100% rating). This variant includes a nut keeper kit and is specified for a DC Power OEM application in China.
What the Ratings Mean for Fit
The 36 kA breaking capacity at 415 V (class S) means this breaker can safely interrupt fault currents up to that level without upstream devices needing to coordinate — critical for panel SCCR compliance in industrial distribution. The adjustable thermal overload (Ir = 88–125 A) lets you dial in the exact motor or feeder FLA without swapping trip units. The 5–10x In magnetic adjustment range covers motor inrush (typically 6–8x FLA) while still providing short-circuit protection. Full N-conductor protection (100% rated) means the neutral pole is not undersized for unbalanced loads or harmonic currents.