Motor protection circuit breaker for 5 A motor circuits
The Siemens SIRIUS 3RV1021-1FA10-0FJ0-ZX95 is a motor protection circuit breaker rated for 5 A continuous current with a CLASS 10 trip characteristic, meaning it will trip within 10 seconds at 7.2× the thermal setting — fast enough to protect a standard induction motor during a stall or locked-rotor event without nuisance tripping on normal start-up transients. The 100 kA breaking capacity at 400 V AC means this device can safely interrupt a bolted fault on a high-capacity distribution panel without upstream fuses needing to clear first; at 690 V the rating drops to 6 kA, which still covers most industrial motor branch circuits on 690 V systems. Phase failure detection is built in, so the breaker will open if one phase drops out — critical for preventing single-phasing damage on delta-connected motors. The 1.5 kW motor rating at 400 V gives a direct sizing reference for a standard 4-pole induction motor.
Integration and mounting on a 35 mm DIN rail
Mounts via screw and snap-on onto 35 mm standard mounting rail per DIN EN 50022. The 45 mm width occupies two standard module positions on the rail. Depth is 96 mm, height 97 mm. Mounting position is any orientation. The IP20 front protection is typical for inside-enclosure use.
Termination and wiring
Main circuit terminals are screw-type, accepting solid or stranded conductors: 2x (1... 2.5 mm²) or 2x (2.5... 6 mm²) per pole. AWG equivalents are 2x (14... 10). No auxiliary contacts are included as standard.