What this part is and what it does
The Siemens 3RV2031-4PA10-ZX95 is a SIRIUS motor-protection circuit breaker designed to protect three-phase induction motors against overload, short circuit, and phase failure. Its Trip Class 10 means it will trip within 10 seconds at 7.2× the thermal setting current — the standard for standard-duty motor starting where the rotor is not locked for long. Phase failure detection is built in, so a lost phase on the line side will trip the breaker rather than letting the motor single-phase and overheat. Rated for breaking capacities of 100 kA at 240 V, 30 kA at 400 V, 5 kA at 500 V, and 2 kA at 690 V, this breaker coordinates with upstream fuses or a main breaker in most industrial panels without requiring a separate current-limiting device. The 36 A continuous rating at both 480 V and 600 V covers a wide band of motor FLA ratings common in North American and European installations.
Mounting and integration
Mounts via screw fixing or snap-on onto a 35 mm standard mounting rail per DIN EN 60715. The 55 mm width and 149 mm depth fit a standard 8-module DIN-rail pitch, leaving room alongside a contactor for a compact motor starter combination. Any mounting position is permitted, which simplifies layout in crowded enclosures. Clearance distances: 50 mm upwards and downwards, 10 mm to the side, zero forwards and backwards. Terminals accept 2× (1…25 mm²) or 1× (1…35 mm²) solid or stranded copper, with M6 screw-type terminals on the main contacts. This covers most motor feeder cables up to about 10 AWG to 2 AWG, depending on the terminal lug.