What it is and where it fits
The Siemens 3RV6311-0BC10 is a SIRIUS circuit breaker designed specifically for starter combinations — meaning it combines motor branch circuit protection (short-circuit and overload) in a single device sized for a motor starter enclosure. It is a 3-pole, size S00 unit rated at 0.2 A operational current at AC-3 duty up to 690 V, with a magnetic instantaneous short-circuit trip set at 2.6 A. This is the part that sits ahead of a contactor in a motor control center or standalone panel, providing coordinated protection for the downstream starter.
What the ratings mean for your panel
The 0.2 A AC-3 rating at 400 V tells you this breaker is sized for a very small motor — fractional horsepower, likely a fan or small pump. The AC-3 category means it is tested for switching squirrel-cage motors including starting, plugging, and inching duty. The magnetic trip at 2.6 A provides instantaneous short-circuit protection; it will clear a fault without waiting for the thermal element, which is critical for limiting let-through energy to the contactor. The 6 kV rated surge voltage resistance and 690 V insulation voltage at pollution degree 3 mean this breaker is suitable for 400 V line-to-line systems with a solidly grounded neutral, and can handle transient overvoltages common in industrial environments without flashover. Mounting is via screw and snap-on onto 35 mm DIN rail per DIN EN 60715, in any orientation. The size S00 footprint — 45 mm wide, 97 mm tall, 96 mm deep — fits the standard S00 slot in a Siemens motor starter assembly. Clearance requirements: 50 mm above and below, 30 mm at the sides. No clearance needed forward or backward.
Integration note for panel builders
Screw-type terminals on top and bottom for the main current circuit. Accepts 2x (0.75 to 2.5 mm²) solid or stranded, or 2x 4 mm². AWG equivalent: 2x (18 to 12) or 2x (20 to 16). Finely stranded with ferrule: 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²). Torque the main contact screws to 0.8 to 1.2 N·m. Operating temperature range -20 to +60 °C; transport range -50 to +80 °C. Relative humidity 10 to 95%. Maximum operating altitude 2000 m above sea level. Shock resistance 25g for 11 ms per IEC 60068-2-27. Power loss 5 W typical.