Motor protection circuit breaker for 4 A loads
The Siemens SIRIUS 3RV1011-1EA20-ZW95 is a 3-pole motor protection circuit breaker rated for 4 A continuous current, sized to protect a 1.5 kW motor at 400 V. Its CLASS 10 trip class means it disconnects within 10 seconds at 7.2× the thermal setting — fast enough for standard induction motor starts but not so fast that it nuisance-trips on normal inrush. Phase failure detection is built in, so a lost phase on the line side will trip the breaker before the motor overheats. Ground fault detection is not included, so if that's required you'd add a separate ground-fault module downstream.
Breaking capacity and coordination
Breaking capacity hits 100 kA at 240 V and 400 V AC, drops to 3 kA at 500 V, and 2 kA at 690 V. At 400 V — the most common industrial supply in Europe and much of Asia — that 100 kA rating means this breaker can interrupt a bolted fault at the panel without needing an upstream current-limiting fuse in most installations. The 690 V rating (2 kA) covers 600 V class North American systems and 690 V European drives. The surge voltage withstand is 6 000 V, which aligns with IEC 60947-2 overvoltage category III for fixed installations.
Termination and mounting
Both the main current circuit and auxiliary/control circuit use spring-loaded terminals — no screwdriver needed for the wire, just strip and push. Main contacts accept 2x (0.25... 2.5 mm²) solid or 2x (0.25... 1.5 mm²) finely stranded with ferrule. AWG equivalent is 2x (24... 14). The breaker snaps onto 35 mm DIN rail per DIN EN 50022, with a screw-fastening option for vibration environments. Width is 45 mm, height 90 mm, depth 81 mm. Mounting position is any, so vertical or horizontal busbars work. The IP20 front face is finger-safe — touch protection against accidental contact with live parts during panel access.