The Siemens 3RV2031-4JA10-ZX95 is a SIRIUS motor protection circuit breaker, designed for motor protection with CLASS 10 trip characteristics — it opens within 10 seconds at 7.2× rated current, fast enough to protect standard induction motors from locked-rotor damage. Rated breaking capacity hits 30 kA at 400 V, so it can safely interrupt fault currents up to that level without cascading upstream. Phase failure detection is built in, meaning it trips if one phase drops out, preventing single-phasing on a motor load.
Mounting and integration
Snaps onto 35 mm DIN rail per DIN EN 60715, screw and snap-on mounting. Clearance requirements: 50 mm above and below, 10 mm to the side, zero forward or backward. The 55 mm width means it occupies three standard 18 mm module positions on the rail — plan your enclosure fill accordingly. Screw terminals on the main circuit accept 2×(1…35 mm²) or 1×(1…50 mm²) solid or stranded copper.
Rating breakdown
Breaking capacity varies by voltage: 100 kA at 240 V, 30 kA at 400 V, 4 kA at 500 V, 2 kA at 690 V. Motor power ratings: 18.5 kW at 230 V, 25 hp at 220/230 V, 50 hp at 460/480 V. Rated voltage span is 20…690 V. Maximum switching frequency in AC-3 duty is 15 operations per hour. Ambient operating temperature range is -20 to +60 °C.