The Siemens 3VA1112-5EF32-0JH0 is a SENTRON molded case circuit breaker (MCCB) rated for 125 A continuous current at 40 °C, with a TM240 thermal-magnetic overcurrent release. Three-pole configuration, line protection version — meaning it's sized for feeder or main breaker duty in a distribution panel, not motor-circuit protection (no undervoltage release, no phase failure detection). Breaking capacity runs 187 kA at 240 V, 121 kA at 415 V, 75.6 kA at 440 V, and 17 kA at 690 V — those numbers cover most industrial service-entrance and sub-distribution scenarios, but at 690 V the 17 kA limit means you need to check upstream fault current if your transformer is stiff. The 70 mm depth and 76.2 mm width fit standard Siemens 3VA panel cutouts; the integrated shunt trip (STL) and the auxiliary contact block (2 aux + 1 trip alarm switch HQ) are factory-fitted, so no field-assembly of the trip accessory.
Ratings & Fit
The rated continuous current Iu is 125 A, and the thermal derating curve is explicit: full rating holds through 50 °C (125 A), then steps down to 120 A at 55 °C, 117.5 A at 60 °C, 115 A at 65 °C, and 112.5 A at 70 °C. If your enclosure ambient runs above 50 °C, use the 55 °C row for sizing — not the 40 °C headline. Rated insulation voltage Ui is 800 V, which covers 480/277 V and 600 V systems comfortably. The front face carries IP40 protection — fine for a closed panel, but not for washdown or outdoor exposure.
Integration & Accessories
The factory-fitted shunt trip (STL) allows remote tripping from a PLC or emergency-stop circuit. The auxiliary contact block (2 aux + 1 trip alarm switch HQ) reports breaker status and trip events back to the control system — no separate alarm module needed. The integrated auxiliary trip is order code 3VA9688-0BL32 — if you're replacing that sub-assembly, that's the part number. No communication function, no ground fault monitoring on this variant.