What the ratings mean for fit
The 3VA1120-3EF32-0KA0 is a Siemens 3VA1 IEC frame 160 molded-case circuit breaker, 3-pole, with a breaking capacity class N rating of Icu=25kA at 415 V AC. That 25 kA is the maximum fault current it can safely interrupt at that voltage — relevant for panel SCCR coordination downstream of a transformer or large feeder. The thermal-magnetic trip unit is a TM240, meaning the fixed thermal element is sized for a 20 A continuous current (In), with an adjustable overload protection range (Ir) from 14 A to 20 A, and a short-circuit magnetic pickup (Ii) adjustable from 8 to 16 times In — so from 160 A to 320 A. This lets you tune the overload band to the actual load current without swapping the breaker body.
Deployment context
This breaker mounts on a DIN rail or panel plate inside an IEC distribution or motor-control center enclosure. The integrated shunt trip (STL) operates on 220–250 V DC or 208–277 V AC, allowing remote tripping from an emergency-stop circuit or a PLC digital output. The nut keeper kit secures the line/load lug connections — a detail that matters during panel wiring when you're torquing multiple breakers on the same bus.