What this breaker carries — and what it means on the panel
The Siemens 3VA1112-5EF32-0DC0 is a 3-pole IEC frame 160 molded-case circuit breaker with a 125 A thermal-magnetic trip unit (TM240) and a 55 kA interrupting capacity at 415 V AC — that is the 'M' breaking capacity class, sized for industrial distribution where fault currents are high but not extreme. The overload protection is adjustable from 88 A to 125 A via the Ir dial; short-circuit pickup (Ii) is fixed at 5 to 10 times In, so on the 125 A setting that means 625 to 1250 A magnetic trip. That range covers motor inrush and transformer magnetizing currents without nuisance tripping on starting, but still clears a bolted fault fast. This order code also ships with an undervoltage release (UVR) rated 208–230 V AC, 50/60 Hz, and two HQ auxiliary switches — the UVR drops the breaker if control voltage falls below about 85 % of rated, which is standard for emergency-stop or power-loss sequences on a machine. The aux switches give status feedback to a PLC or annunciator panel. A nut keeper kit is included in the package for secure mounting in a panel where vibration is a concern.
Where it fits in the panel
This breaker mounts on a DIN rail or directly to a backplate via the included nut keeper kit — the 3VA1 frame uses a standard screw-clamp lug pattern, so it swaps into existing Siemens 3VA cutouts without re-drilling the gland plate. The UVR and aux switches are factory-installed; no field wiring of add-on modules is needed, which saves a step during panel build-out.