MCCB for line protection — 125 A, 121 kA at 240 V
The Siemens SENTRON 3VA1112-4EF36-0JC0 is a 3-pole molded case circuit breaker (MCCB) rated for continuous current of 125 A at 40 °C, with a TM240 thermal-magnetic overcurrent release. Its interrupting capacity reaches 121 kA at 240 V AC, 75.6 kA at 415 V, and 52.5 kA at 440 V — figures that cover most low-voltage distribution fault levels without cascading upstream. The breaker carries a shunt trip (STL) auxiliary release and two high-quality auxiliary switches (HQ) for remote status feedback.
Thermal derating and ambient limits
The 125 A rating holds flat from 40 °C to 50 °C, then derates to 120 A at 55 °C, 117.5 A at 60 °C, 115 A at 65 °C, and 112.5 A at 70 °C. Operating ambient range is -25 °C to 70 °C; storage range is -40 °C to 80 °C. The front face carries IP40 protection — suitable for enclosed panel mounting, not for washdown environments.
Physical fit and auxiliaries
Dimensions are 130 mm height, 76.2 mm width, and 70 mm depth — a standard 3-pole MCCB footprint that mounts on a DIN rail or panel base. The integrated shunt trip (STL) is designed for remote tripping; the two HQ auxiliary switches provide status contacts for PLC or SCADA inputs. No undervoltage release, no ground-fault monitoring, and no communication module are fitted on this variant.