The Siemens 3RV2021-0GA10-ZW96 is a SIRIUS motor protection circuit breaker in size S0, designed to protect three-phase motors against overload, short-circuit, and phase failure. Its Trip Class 10 means it trips within 10 seconds at 7.2× the thermal setting — fast enough to protect a motor winding during a stall without nuisance tripping on a normal start. Phase failure detection is built in, so a lost leg on the line side drops the load immediately rather than letting the motor single-phase and burn.
Mounting and panel fit
Width is 45 mm, depth 97 mm, height 97 mm. The breaker mounts on a 35 mm DIN rail per DIN EN 60715 with either a screw or snap-on fastening — a panel builder can clip it onto the rail without tools or bolt it for vibration resistance. Clearance requirements: 50 mm above and below, 30 mm at the sides, zero forward or backward. That means it fits a standard 200 mm deep enclosure with room for wiring ducts. Screw-type terminals on the main circuit accept up to 2× 10 mm² stranded or solid.
Operating conditions
Rated operating voltage spans 20 to 690 V. Ambient temperature during operation is -20 to +60 °C, with temperature compensation active across that same range so the thermal trip curve stays accurate regardless of cabinet heat. Storage and transport range is -50 to +80 °C. Maximum switching rate at AC-3 duty is 15 operations per hour.