The Siemens 3RV2811-1BD10 is a SIRIUS-branded circuit breaker designed specifically for transformer protection, complying with UL 489 and CSA C22.2 No. 5. It occupies the compact Size S00 footprint — 45 mm wide, 97 mm deep, 144 mm tall — and mounts via screw fixing or snap-on onto a 35 mm DIN rail per DIN EN 60715. Its interrupting capacity hits 100 kA at 400 V AC and 500 V AC, dropping to 10 kA at 690 V AC — meaning it can safely clear a fault up to 100 kA at typical industrial 400 V distribution levels without upstream damage. For backup fuse coordination, the spec calls for gG 25 A fuses at 400 V and 500 V, and gG 20 A at 690 V — a detail that matters when designing selective coordination in a panel.
Mounting position is any, which gives flexibility in crowded enclosures. Terminal screws are M4, requiring a Pozidriv size 2 tip with a shaft diameter of 5 to 6 mm. Clearance distances are specified: 70 mm upwards and downwards, 30 mm at the sides, zero forwards and backwards — so you can pack it tight front-to-back but need vertical breathing room.
Environmental and operating range
The rated voltage envelope is 20 to 690 V, covering most low-voltage industrial systems.