What it is and what it does
The Siemens 3RV2311-1BC20 is a SIRIUS circuit breaker designed specifically for starter combinations — the kind that sits ahead of a contactor and overload to form a coordinated motor-starting assembly. It is built for screw and snap-on mounting onto 35 mm DIN rail per DIN EN 60715, and it accepts spring-loaded terminals for the main current circuit. Its headline interrupting rating is 100 kA at 400 V AC — that is the fault current it can safely clear without welding contacts or venting arc gas into the panel. At 690 V the rating drops to 10 kA, which still covers most industrial distribution faults. For selective coordination upstream, the fuse backup limits are gL/gG 25 A at 400 V and 500 V, and gL/gG 20 A at 690 V. Motor full-load current equivalents: 0.13 hp at 230 V, 1 hp at 460/480 V, and 1 hp at 575/600 V. The 3RV2311-1BC20 is rated for AC-3 switching duty at 15 operations per hour maximum, same for AC-3e. That rate suits intermittent motor starting — not continuous jogging or high-cycle applications.
Panel integration and clearances
The breaker occupies 45 mm width on the DIN rail, with a depth of 97 mm and height of 106 mm. Mounting position is any orientation. Required free space around the device: 50 mm upward, 50 mm downward, 30 mm to the side, zero forward or backward clearance needed. That means it can sit flush against the backpanel or enclosure wall. Terminals accept 2 x 0.5 to 4 mm² solid or stranded copper. Operating temperature range is -20 to +60 °C; storage and transport range is -50 to +80 °C.