What this breaker does on the line
The Siemens 3VA1112-6MH32-0AG0 is a 3-pole IEC frame 160 molded-case circuit breaker rated for 125 A continuous current, with a breaking capacity of 70 kA at 415 V (class H). That Icu rating means it can safely interrupt a fault current up to 70,000 A without welding or rupturing — critical for high-fault installations like transformer secondaries or large motor control centers where upstream coordination demands a high-interrupt device. This variant ships with a TM120M thermal-magnetic trip unit configured for starter protection (AM characteristic). The thermal element is omitted — no overload protection — so it's a short-circuit-only device intended to sit upstream of a separate motor overload relay. The magnetic short-circuit pickup is adjustable from 5 to 15 times In (625 A to 1875 A), letting you dial in the instantaneous trip point to ride through motor inrush without nuisance tripping.
Panel integration and accessories
The breaker includes a nut keeper kit for secure mounting in the panel. It also carries one auxiliary switch (HP) and one trip alarm switch (HP) — both factory-fitted, so you don't lose a slot on the DIN rail for add-on blocks. The auxiliary switch signals the breaker's open/closed position; the trip alarm switch changes state only when the breaker trips on fault, giving a dedicated remote indication for the SCADA or PLC input.