What it is and what it does
The Siemens 3VA1112-3EF32-0JH0 is a 3-pole IEC molded-case circuit breaker from the 3VA1 series, built on a 160 A frame with a 125 A continuous rating (In). Its breaking capacity class N delivers 25 kA at 415 V AC — enough to clear a hard fault on a distribution board or motor control center without cascading upstream. The TM240 thermal-magnetic trip unit gives adjustable overload protection (Ir = 88–125 A) and fixed short-circuit pickup (Ii = 5–10 × In, so 625–1250 A), which is a standard range for motor feeders and general power circuits. A shunt trip (STL) rated 110–127 V DC/AC is factory-installed, along with two auxiliary switches (HQ) and one trip alarm switch (HQ).
Deployment context
The 3VA1 frame mounts on a DIN rail or panel base inside a switchboard or MCC bucket. The 25 kA SCCR at 415 V makes it suitable for IEC distribution networks where fault levels are moderate — typical for commercial buildings, light industrial lines, and motor feeder circuits. The shunt trip allows remote tripping from a safety relay or emergency-stop pushbutton, which is common in panel-level safety circuits.