What it is and what it does
The Siemens 3RV2411-1HA10-ZX95 is a SIRIUS circuit breaker designed specifically for transformer protection — meaning its trip curve and ratings are matched to the inrush and overload profile of a transformer, not a standard motor or feeder. It carries a 100 kA breaking capacity at both 230 V and 400 V, so it can safely interrupt very high fault currents without upstream damage — a key spec for panel selectivity. The Trip Class 10 rating means it will trip within 10 seconds at 7.2× the thermal setting, which is fast enough to protect most distribution transformers from sustained overloads.
Mounting and integration
Mounts via screw and snap-on onto 35 mm DIN rail per DIN EN 60715, in any orientation — no derating for sideways or upside-down installation. Dimensions are 97 mm deep, 45 mm wide, 97 mm tall — a compact 45 mm footprint that fits standard 45 mm-wide DIN slots, leaving room for adjacent devices. Requires 50 mm clearance above and below, 30 mm at the sides, and zero clearance forwards or backwards — tight panel layouts are fine as long as vertical airflow is respected.
Electrical ratings and coordination
The fuse backup ratings are 50 A gL/gG at 400 V, 40 A at 500 V, and 35 A at 690 V — these are the maximum fuse sizes that still allow the breaker to clear a fault without exceeding its withstand. Breaking capacity drops with voltage: 100 kA at 400 V, 42 kA at 500 V, 4 kA at 690 V — the 690 V rating is low, so verify the available fault current at that voltage level. Phase failure detection is built in, so it will trip if one phase drops out — important for transformer protection where single-phasing can cause overheating.