The Siemens SIRIUS 3RV1021-1CA15-ZW95 is a motor protection circuit breaker sized for a 0.75 kW motor at 400 V AC. It carries a continuous rated current of 2.5 A and trips under Class 10 overload protection, meaning it clears a stalled-rotor condition within 10 seconds at 7.2× Ie — fast enough to protect a standard induction motor winding before insulation damage sets in.
Breaking capacity and coordination
This breaker delivers 100 kA breaking capacity at 400 V AC, which is the typical panel fault level for a 400 V distribution board downstream of a 1 MVA transformer. At 690 V AC the rating drops to 8 kA — still adequate for most 690 V motor circuits but worth noting if the available fault current exceeds that figure. The high 100 kA rating holds through 500 V, so it coordinates cleanly with upstream fuses or a moulded-case breaker without requiring a current-limiting device.
Mounting and wiring
Mounts via screw and snap-on onto 35 mm standard mounting rail per DIN EN 50022. The 45 mm width takes one standard DIN slot. Main circuit terminals accept 2x (1... 2.5 mm²) stranded or 2x (0.75... 2.5 mm²) solid; auxiliary and control circuit terminals are screw-type as well. Zero clearance needed at the sides or rear — stack them tight in a panel.
Auxiliary switch and environmental limits
The product extension auxiliary switch is transverse-designed and rated at 1 A at 24 V, 0.5 A at 230 V, and 0.15 A at 60 V — enough to signal a trip back to a PLC input or a status lamp. Phase failure detection is built in; ground fault detection is not. Operating temperature range is -20 to +60 °C, storage and transport -50 to +80 °C. Shock resistance is 25 g for 11 ms. IP20 on the front face keeps fingers out but the breaker is intended for inside an enclosure, not exposed.