What it is and what it does
The Siemens 3VA1112-4EF36-0CC0 is a SENTRON molded case circuit breaker (MCCB) rated for line protection in distribution panels. It carries a continuous current of 125 A through 40 °C ambient, derating to 114 A at 70 °C. Breaking capacity is 121 kA at 240 V AC, 75.6 kA at 415 V, 52.5 kA at 440 V, and 11.9 kA at both 500 V and 690 V. That 121 kA at 240 V means it can interrupt a fault up to that level without upstream cascading — useful for high-fault utility feeds or transformer secondaries. Three-pole construction with an undervoltage release (UVR) fitted and two auxiliary switches HQ. The UVR trips the breaker 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.
Panel fit and integration
Dimensions: 130 mm height, 76.2 mm width, 70 mm depth. The 76.2 mm width is a standard 3-pole MCCB footprint — it drops into a panel cutout sized for a 3-pole SENTRON frame without re-drilling the gland plate. Maximum power loss is 30.6 W. That matters for thermal management inside a sealed enclosure — account for that dissipation when sizing ventilation or calculating internal temperature rise.