The Siemens SIRIUS 3RV1021-1JA10-ZW95 is a motor-protective circuit breaker rated for 10 A continuous current with Trip Class 10 thermal overload protection. It breaks 100 kA at 400 V AC, so it handles high fault currents common on industrial motor branch circuits without needing an upstream fuse for short-circuit coordination up to that level. Snap it onto a 35 mm DIN rail per DIN EN 50022, or screw-mount it. At 45 mm wide, it fits a standard modular panel slot. Screw terminals on both main and auxiliary/control circuits — strip and torque, no special tooling.
What the ratings mean for the panel
The 10 A continuous rating sets the motor FLA it can protect. Class 10 trip means it disconnects within 10 seconds at 600% of the thermal setting — fast enough for most standard squirrel-cage motors starting under load. Phase failure detection is built in, so a lost leg won't single-phase the motor and cook the winding. Breaking capacity is 100 kA at 400 V AC and 240 V AC, 42 kA at 500 V AC, and 6 kA at 690 V AC. At 400 V, that 100 kA SCCR means it clears a bolted fault without the arc flash escalating — critical for panel coordination studies. The 4 kW motor rating at 400 V lines up with a typical 10 A motor full-load current on a 400 V line. IP20 on the front means fingers won't reach live parts inside the panel. The -50 to +80 °C storage range and -20 to +60 °C operating range cover unheated warehouses and hot machine cabinets. Shock rated at 25g / 11 ms — it stays calibrated on a vibrating conveyor or pump skid.
Integration and wiring
Mounts in any position on 35 mm DIN rail (DIN EN 50022) or with screws. Zero clearance needed at the sides or back — 0 mm backwards and 0 mm at the side — so you can pack it tight in a crowded panel. Dimensions: 45 mm wide, 97 mm tall, 96 mm deep. Screw terminals accept 1x to 2x (1... 2.5 mm²) solid or stranded, and 2x (2.5... 6 mm²) solid or stranded on the main circuit. Fine-stranded with ferrule: same ranges. AWG equivalents: 2x (14... 10). Auxiliary and control circuits also use screw terminals. An auxiliary switch can be added — the product extension for that is supported.
Compliance and documentation
RoHS compliant per the substance prohibition date of 01.05.2012. The rated impulse withstand voltage is 6 000 V, and operating frequency for AC-3 duty is max 15 operations per hour. Power dissipation at rated current in hot state: 9.25 W total, 3.1 W per pole.