MCCB for high-fault panels
The Siemens SENTRON 3VA1112-6EF36-0BA0 is a 3-pole molded case circuit breaker rated for 125 A continuous current (Iu) with a TM240 thermal-magnetic release. It's built for line protection in distribution panels where fault currents can hit 220 kA at 240 V or 154 kA at 415 V — that's the interrupting capacity you need upstream of a transformer or on a high-capacity bus. The 800 V rated insulation voltage (Ui) gives headroom for 480/600 V systems without derating the insulation path.
Breaking capacity across voltage levels
This MCCB delivers 220 kA at 240 V, 154 kA at 415 V, 75.6 kA at 440 V, and 17 kA at 690 V. Those numbers tell you where it's meant to sit: on the secondary of a large transformer or in a main feeder where available fault current is high. At 690 V the 17 kA rating still covers most industrial motor-control center bus faults, but the real strength is in the sub-480 V range.
Thermal derating — what 125 A actually means at panel temperature
The 125 A rating holds flat from 40 °C to 50 °C. At 55 °C it's 120 A, at 60 °C it's 117.5 A, at 65 °C it's 115 A, and at 70 °C it's 112.5 A. If your panel ambient runs 55 °C or higher, size the load side for the derated figure — the TM240 release won't trip early, but the continuous rating is what the thermal element is calibrated to. Operating range is -25 °C to 70 °C; storage from -40 °C to 80 °C.
Integrated undervoltage release
This version includes an undervoltage release (UVR) as the auxiliary release, designated 3VA9608-0BB11. That means the breaker trips when control voltage drops below a threshold — common in safety circuits or emergency-stop chains where loss of control power must open the main contacts. No auxiliary contact block is fitted (without), and there's no voltage trigger or communication function. The trip indicator is also absent, so you won't get a local flag; plan for a remote indication path if needed.
Panel fit and footprint
Dimensions: 70 mm depth, 76.2 mm width, 130 mm height. The 76.2 mm width is a standard 3-pole MCCB footprint — it occupies three 25.4 mm (1-inch) module positions on a DIN rail or panel-mount plate. IP40 on the front means protection against tools and small wires, but not against water ingress; keep it in an enclosed panel. The reference code per DIN EN 81346-2 is Q, which classifies it as a switching device in the functional system.