What it is and where it lands
The Siemens 3RV1011-1BA10-ZX95 is a SIRIUS motor protection circuit breaker — the part that sits between the contactor and the motor in a standard motor control center, sized for a 45 mm DIN-rail slot. It combines short-circuit and overload protection in one device, with a Trip Class 10 thermal curve that matches standard induction motor starting profiles. Rated breaking capacity hits 100 kA at both 240 V and 400 V AC — that's fault-current interruption capability for high-capacity distribution panels without needing an upstream current-limiting fuse in most configurations.
Mounting and fit
Snaps onto 35 mm DIN rail per DIN EN 60715 (screw and snap-on). The 45 mm width and 75 mm depth fit standard panel layouts; any mounting position is permitted, so vertical or horizontal rail orientation works. Clearance: 20 mm above and below, 9 mm to the side, zero forwards and backwards — tight panel packing is possible. Terminals are M3 screw-type for the main circuit, accepting 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²) solid or stranded copper.
Protection and duty ratings
Phase failure detection is built in — the breaker trips on loss of one phase, preventing single-phasing damage to the motor. Ground fault detection is not included. Rated operational voltage covers 20 to 690 V. At 480 V the continuous current rating is 2 A; at 600 V also 2 A. Breaking capacity at 690 V drops to 2 kA. Maximum switching frequency in AC-3 (motor) duty is 15 operations per hour — fine for pump and fan cycling, not for high-speed jogging applications. Operating temperature range is -20 to +60 °C; storage and transport range is -50 to +80 °C.