The Siemens 3RV2431-4JA10 is a SIRIUS-brand circuit breaker specifically designed for transformer protection. Interrupting capacity is 100 kA at 240 VAC and 30 kA at 400 VAC, per the datasheet. If one phase drops out, the breaker trips — a critical feature for transformer primary protection where single-phasing can overheat the remaining windings. No ground fault detection on this variant.
Depth is 149 mm, height 140 mm. Mounting position is any orientation. That 50 mm vertical clearance is for arc-chamber venting — don't crowd it against cable ducts or panel walls. Main circuit terminals are screw-type, accepting 2× (1 to 35 mm²) or 1× (1 to 50 mm²) solid or stranded copper. Terminal screw size is M6. Strip length and torque values per the installation instructions — the 50 mm² single-conductor capacity is useful for feeding a transformer primary with a single large cable.
Environmental and electrical ratings
Rated operational voltage spans 20 to 690 V. Motor-switching capability at AC-3 duty is 15 operations per hour maximum. That's a switching rate, not a continuous current rating — the breaker is sized for transformer primary protection, not frequent motor starting. Power ratings at various voltages: 18.5 kW at 230 V, 25 hp at 220/230 V, 50 hp at 460/480 V, 60 hp at 575/600 V. Current ratings: 65 A at 480 V, 62 A at 600 V.
Lifecycle status is listed as current production. This is an active catalog item in the SIRIUS range, not a phase-out or NRND part.