The Siemens SIRIUS 3RV2021-1CA10-ZW96 is a motor protection circuit breaker, designed to protect motors against overload and short-circuit. It carries a Class 10 trip characteristic, meaning it will trip within 10 seconds at 7.2 times the thermal setting — the standard for protecting standard induction motors during start-up. The unit is rated for a breaking capacity of 100 kA at 400 V AC, so it can safely interrupt fault currents up to that level without upstream fuses needing to clear first.
Mounting and panel fit
Mounts via screw or snap-on onto 35 mm DIN rail per DIN EN 60715. The 45 mm width and 97 mm depth mean it takes up a single 45 mm module slot on the rail — that's another SKU that fits a standard panel layout without surprises. Mounting position is any, so it works in horizontal or vertical bus runs. Clearance: 50 mm above and below, 30 mm to the side, zero forward or backward.
Key ratings and what they mean for the line
Phase failure detection is built in — if one phase drops out, the breaker trips, preventing single-phasing damage to the motor. Ground fault detection is not included; that's handled separately by a GFCI or residual current device if required. The operating temperature range is -20 to +60 °C, which covers most indoor panel environments but not direct sun or oven-adjacent locations. Storage and transport range is -50 to +80 °C.