What it is and what it does
The Siemens 3VA1112-6MH32-0HH0 is a 3-pole IEC frame 160 molded case circuit breaker rated 125 A with a high breaking capacity of 70 kA at 415 V AC. It's built for motor starter protection using a TM120M thermal-magnetic trip unit set for short-circuit protection only (no overload function), with an adjustable instantaneous trip range of 5 to 15 times In.
Key ratings and what they mean for your panel
The 70 kA Icu at 415 V puts this in breaking capacity class H — it can safely interrupt fault currents up to that level without failing, which matters when you're coordinating downstream breakers or feeding a motor starter in a high-fault plant. The 125 A continuous rating matches a typical motor full-load current for a 75–90 kW motor, but since there's no overload protection built in, you'll need a separate overload relay upstream or in the starter. The shunt trip (STL) operates on 12–30 V DC or 24 V AC 50/60 Hz, letting you remotely trip the breaker from an E-stop or safety relay. Two auxiliary switches (HQ) and one trip alarm switch (HQ) give status feedback to a PLC or annunciator panel.
Deployment context
Mounts on a standard DIN rail or panel-mount in an IEC enclosure. The nut keeper kit simplifies panel assembly — no dropped hardware when you're working in tight spots.