What it is and what it does
The Siemens 3RV2021-1FA10-ZW96 is a SIRIUS motor protection circuit breaker designed for motor protection, with a Class 10 trip characteristic that clears overloads fast enough to protect standard induction motors during start-up. Rated for 20 to 690 V, it delivers 100 kA short-circuit breaking capacity at 240 V and 400 V AC, meaning it can interrupt a fault up to that level without upstream devices needing to clear it — a key spec for SCCR coordination in industrial panels. Phase failure detection is built in, so if one phase drops out on a three-phase motor, the breaker trips before single-phasing cooks the winding.
Mounting and integration
Mounts via screw or snap-on onto 35 mm DIN rail per DIN EN 60715, in any position — no derating for sideways or inverted orientation. Dimensions are 97 mm deep, 45 mm wide, and 97 mm tall, with 50 mm clearance needed above and below, 30 mm to the side, and zero clearance forward or backward. Main circuit terminals accept 2x 1 to 2.5 mm² or 2x 2.5 to 10 mm² solid or stranded wire, with M4 screw terminals for the main contacts.