The Siemens 3RV6411-1KA10 is a SIRIUS circuit breaker designed specifically for transformer protection, with a rated operational current of 12.5 A in AC-3 duty and a Class 10 trip characteristic. That Class 10 means it trips fast enough to protect a transformer winding against sustained overload without nuisance tripping on inrush — a common headache when a standard motor-protective breaker is used instead. Rated for 690 V AC-3 and 50/60 Hz, it handles the primary-side switching of small to medium transformers in control panels and distribution boards.
Mounting and integration
Mounts via screw and snap-on onto 35 mm DIN rail per DIN EN 60715, in any position. The S00 frame size keeps the width to 45 mm, depth 96 mm, height 97 mm — fits a standard 45 mm DIN slot. Clearance: 50 mm above and below, 30 mm at the sides, nothing needed front or back. Screw-type terminals accept 2x (0.75 to 2.5 mm²) solid or stranded, or 2x 4 mm²; torque to 0.8 to 1.2 N·m.
Environmental and mechanical ratings
Operating temperature -20 to +60 °C, transport/storage -50 to +80 °C. Relative humidity 10 to 95 %. Shock resistant to 25 g / 11 ms per IEC 60068-2-27. Installation altitude up to 2000 m above sea level. Total power loss 7 W typical.