Motor protection circuit breaker, SIRIUS, 100 kA at 400 V
The Siemens 3RV2021-0JA10-ZW96 is a SIRIUS motor protection circuit breaker (size S0) designed for motor protection, with a Class 10 trip characteristic that matches standard induction motor startup curves — it holds through the inrush without nuisance tripping, then clears a locked-rotor fault fast enough to protect the winding insulation. Rated breaking capacity hits 100 kA at 400 V AC and holds that 100 kA across the 240 V, 500 V, and 690 V AC ratings too — so it handles high-fault utility feeds without needing an upstream current-limiting fuse in most panels. Phase failure detection is built in, which means the breaker trips if one phase drops out — critical for preventing single-phasing damage on a three-phase motor.
Mounting and integration
Mounts via screw or snap-on onto 35 mm DIN rail per DIN EN 60715, in any position. The S0 frame (45 mm wide, 97 mm deep) fits standard motor-starter footprints — direct swap into existing S0-based panels without re-drilling the backplate. Clearance requirements: 50 mm above and below, 30 mm to the side, zero forward or backward (–). That keeps the arc-chamber vents unobstructed and meets the manufacturer's spacing for full breaking capacity. Main-circuit terminals accept 2x 1–2.5 mm² or 2x 2.5–10 mm² solid/stranded; screwdriver shaft 5–6 mm. M4 terminal screws on the main contacts.