Motor protection circuit breaker for DIN-rail panels
The Siemens 3RV1021-1JA15-ZW96 is a SIRIUS motor protection circuit breaker designed for screw and snap-on mounting onto 35 mm standard mounting rail per DIN EN 50022, making it a direct fit for any IEC-style control panel. It carries a continuous current rated value of 10 A and is rated for 4 kW at 400 V, which covers a typical small motor on a pump or conveyor. The CLASS 10 trip class means it will trip within 10 seconds at 7.2× rated current, matching the thermal characteristic of standard induction motors during startup — important for avoiding nuisance trips on high-inertia loads.
Breaking capacity and fault clearing
This breaker delivers 100 kA breaking capacity at both 240 V and 400 V AC, dropping to 42 kA at 500 V and 6 kA at 690 V. At 400 V — the most common industrial distribution voltage — the 100 kA figure means it can safely interrupt a bolted fault on a high-capacity transformer secondary without needing an upstream current-limiting fuse. The phase failure detection built into the SIRIUS design adds a layer of protection for three-phase motors running on supply legs that may drop one phase.
Terminal capacity and wiring
Screw-type terminals on the main current circuit accept solid conductors: 2x (0.5 … 1.5 mm²) and 2x (0.75 … 2.5 mm²). Stranded conductors: 2x (1 … 2.5 mm²) and 2x (2.5 … 6 mm²). The auxiliary switch is transverse design with its own terminal set. The IP20 rating on the front means the breaker is touch-safe for panel interiors but not suitable for washdown environments. Mounting position is any, which simplifies layout in tight enclosures.
Environmental and mechanical limits
Operating temperature range is -20 to +60 °C; storage and transport range is -50 to +80 °C. Shock resistance is rated at 25g / 11 ms, which covers most industrial vibration environments. Maximum operating altitude is 2 000 m without derating. The mechanical endurance of the main contacts is typically 100 000 operations, and the maximum switching frequency in AC-3 duty is 15 operations per hour.