125 A MCCB with undervoltage release — line protection for distribution panels
The SENTRON 3VA1112-3EF36-0DC0 is a 3-pole molded case circuit breaker rated for 125 A continuous current at 40 °C, designed for line protection in low-voltage distribution. Its breaking capacity reaches 75.6 kA at 240 V AC, 52.5 kA at 415 V, and 32 kA at 440 V — figures that determine whether this breaker clears a fault without upstream coordination issues. The 125 A rating holds steady through 50 °C, then derates to 122 A at 55 °C and 114 A at 70 °C, so panel ambient temperature directly governs the usable load. This unit ships with an integrated undervoltage release (UVR) and two HQ auxiliary switches, factory-fitted. The UVR trips the breaker when control voltage drops below a threshold — common in emergency-stop chains or upstream power-loss detection. The auxiliary switches provide status feedback to a PLC or indication lamp without adding external interposing relays.
Physical fit and panel integration
Dimensions are 130 mm height, 76.2 mm width, and 70 mm depth — a 3-pole footprint that matches the SENTRON 3VA family. The 70 mm depth is the dimension that governs gland-plate clearance and whether the breaker fits a shallow enclosure. Width at 76.2 mm (3 inches) is the standard 3-pole MCCB pitch; verify that the DIN-rail or mounting-plate holes align with the existing cutout if replacing a different brand. Rated insulation voltage is 800 V, and the operating temperature range runs from -25 °C to 70 °C. Storage range extends from -40 °C to 80 °C. Maximum power dissipation is 30.6 W — a figure to include in enclosure thermal calculations, especially in sealed or high-density panels.