The Siemens 3RV2021-4EA10-ZW97 is a SIRIUS motor-protective circuit breaker designed for motor protection, with a Class 10 trip characteristic. It snaps onto a 35 mm DIN rail per DIN EN 60715 and uses screw-type terminals for the main current circuit. The 45 mm width and 97 mm depth fit standard panel layouts, and the any-position mounting gives flexibility in crowded enclosures.
Breaking capacity and motor ratings
This breaker delivers 100 kA breaking capacity at 240 V, 25 kA at 400 V, 5 kA at 500 V, and 2 kA at 690 V. The Class 10 trip means it clears a locked-rotor condition within 10 seconds at 7.2× the thermal setting — standard for general-purpose motor starting. Motor horsepower ratings span 2 hp at 110/120 V up to 20 hp at 460/480 V, with a 5 hp rating at 230 V and 10 hp at 220/230 V. Phase failure detection is built in; ground fault detection is not.
Mounting and clearances
Mounts via screw or snap-on onto 35 mm DIN rail. Required clearances: 50 mm upward and downward, 30 mm to the side, zero forward or backward. The M4 main contact terminals accept 2×(1–2.5 mm²) or 2×(2.5–10 mm²) solid or stranded wire. Operating temperature range is –20 to +60 °C; storage and transport range is –50 to +80 °C.