Transformer Protection Circuit Breaker — SIRIUS 3RV2431-4EA10
Built-in phase failure detection ensures the breaker trips on loss of any phase, protecting three-phase transformers from single-phasing damage.
Dimensions of 55 mm width, 140 mm height, and 149 mm depth mean it occupies a standard three-module footprint on the rail; clearance requirements of 50 mm upward and downward, 10 mm to the side should be factored into gland-plate and busbar planning. Screw-type terminals on the main current circuit accept 2x (1–25 mm²) or 1x (1–35 mm²) solid or stranded copper, with M6 bolt size for the main contacts — no special crimp tooling needed for field replacement.
Environmental and Operating Range
Rated switching frequency at AC-3 and AC-3e duty is 15 cycles per hour maximum, which suits transformer primary switching rather than high-cycle motor starting.