The Siemens 3RV2811-0CD10 is a SIRIUS-branded circuit breaker designed specifically for transformer protection, certified to UL 489 and CSA C22.2 No. 5. It's not a general-purpose motor protective breaker — the trip curve and interrupting rating are tuned for inrush-heavy transformer primaries, so don't swap it into a motor branch without checking coordination. Rated operating voltage spans 20 to 690 V, with a symmetrical breaking capacity of 100 kA at 400, 500, and 690 V AC — that's a solid SCCR for a size S00 frame. At 230 V the breaking capacity drops to 0 kW (the rating is listed as 0 kW at 230 V), meaning the part is not intended for power switching at that voltage; it's a protective device, not a load switch. Mechanical life on the main contacts is rated at 100,000 operations typical, with a maximum switching rate of 15 operations per hour under AC-3 duty. That's fine for infrequent transformer isolation or backup protection; it's not a cycling contactor.
That's tighter than many MCCB clearances — useful for dense panels where every millimeter counts. Mounting position is any orientation. Terminals are M4 screw-type for the main circuit, accepting 1 to 10 mm² solid or stranded, up to 2x 10 mm². The screwdriver spec calls for a Pozidriv size 2 tip with shaft diameter 5 to 6 mm — keep that on the panel-builder's tool list.
No ground-fault or phase-failure detection built in — this is a straight thermal-magnetic breaker. If you need those functions, you'd add an external relay or step up to a SIRIUS 3RV2 with integrated monitoring.
This is a current-production Siemens part, sourced through independent distribution channels. No minimum buy required for single-line quantities.