Transformer-protection circuit breaker with 100 kA interrupting capacity
The Siemens 3RV2411-0EA15 is a SIRIUS-brand circuit breaker designed specifically for transformer protection, not general motor or feeder duty. Its 100 kA breaking capacity at 400 V AC means it can safely interrupt fault currents up to that level without upstream fuses — a key spec for panel selectivity studies where the transformer inrush and secondary-side fault current must be coordinated. Trip Class 10 defines the maximum trip time at 7.2× rated current: 10 seconds. For a transformer primary protector, that thermal curve is sized to ride through magnetizing inrush without nuisance tripping while still clearing a sustained overload. Phase failure detection is built in, so a lost phase on the secondary side will trip the primary breaker — a feature not universal on basic MCPs.
Mounting and wiring
Mounts via screw and snap-on onto 35 mm standard mounting rail per DIN EN 60715. The 45 mm width is a standard 2-module footprint on that rail. Screw-type terminals on the main circuit accept 2× (0.5 to 1.5 mm²) solid or stranded, or 2× (0.75 to 2.5 mm²) — strip length per the manufacturer's torque spec, not guessed. Any mounting position is permitted, which simplifies panel layout when the transformer is in a tight enclosure.