Siemens SENTRON 3VA1112-4EF36-0HA0 — 125 A MCCB with Shunt Trip
The Siemens SENTRON 3VA1112-4EF36-0HA0 is a 3-pole molded case circuit breaker (MCCB) rated for line protection, carrying 125 A continuously at 40 °C. Its breaking capacity hits 121 kA at 240 V AC — that's the figure that governs fault clearing on a 240 V distribution bus, not the higher-voltage numbers. The shunt trip release (STL) lets you remotely trip the breaker via a control signal, which is useful for emergency-stop circuits or interlocking schemes where you need to drop a feeder without pulling the handle.
Ratings and What They Mean for Your Panel
At 415 V the interrupting rating drops to 75.6 kA, at 440 V to 52.5 kA, and at 500 V and 690 V it holds at 11.9 kA. The 800 V rated insulation voltage (Ui) tells you the breaker's internal clearance is designed for 800 V systems, but the actual breaking numbers above 500 V are modest — this is a 240/415 V workhorse, not a 690 V main. The thermal-magnetic release is a TM240, meaning the thermal element is calibrated for a 240 A frame, but the actual continuous current you can pull depends on the ambient derating curve: it carries 125 A up to 50 °C, then tapers to 114 A at 70 °C. If your panel runs hot, that derating is the number to size against.
Physical Fit and Integration
The breaker measures 130 mm high, 76.2 mm wide, and 70 mm deep — a standard SENTRON 3VA footprint that drops into the same panel cutout as other 3VA frame sizes. No communication module onboard, no undervoltage release, no ground-fault monitoring. The shunt trip is the only auxiliary release; if you need undervoltage protection or a separate alarm contact, you'll add those as external accessories. Power loss at full load is 28.1 W — enough to consider ventilation if the breaker is packed tightly in a sealed enclosure.