SIRIUS motor protection circuit breaker, 3RV2031-4PA15
The Siemens SIRIUS 3RV2031-4PA15 is a motor protection circuit breaker with CLASS 10 trip characteristic. Rated breaking capacity is 30 kA at 400 V AC, 100 kA at 240 V, and 5 kA at 500 V, with a 2 kA rating at 690 V. These figures tell you the maximum fault current the breaker can safely interrupt at each voltage level — critical for coordination with upstream protective devices in a panel SCCR study. Phase failure detection is built in; ground fault detection is not. On a furnace or process line where a single-phased motor can cause a costly shutdown, this breaker will drop the load when one phase is lost, preventing single-phase heating and winding damage.
Mounting and integration
Mounts via screw or snap-on onto 35 mm DIN rail per DIN EN 60715. The 55 mm width and 149 mm depth fit a standard 8-module-wide enclosure slot; any mounting position is allowed. Terminal capacity accepts 2× (0.5 to 1.5 mm²) or 2× (0.75 to 2.5 mm²) solid or stranded wire, with M6 main contact bolts. Clearance: 50 mm above and below the device, 10 mm to the side. The 50 mm vertical clearance is the minimum to allow arc gases to vent and to keep heat from adjacent components from affecting the thermal trip.
Environmental and lifecycle
Rated operational voltage span is 20 to 690 V AC. The auxiliary contact ratings at various control voltages are provided: 1 A at 24 V, 0.15 A at 60 V, 0.5 A at 230 V, and 125 A at 400 V — note the 125 A at 400 V is likely a typographical artifact for the main contact rating; the auxiliary contacts carry lower currents as listed.