SIRIUS 3RV2742-5DD10 — system protection breaker, S3 frame
The Siemens SIRIUS 3RV2742-5DD10 is a 25 A rated circuit breaker in the S3 frame size, designed for system protection per UL 489 and CSA C22.2 No. 5. It combines a thermal overload release and a magnetic short-circuit trip in one package, sized for motor branch circuits and distribution panels where UL 489 listing is required by code. Breaking capacity reaches 100 kA at 240 V AC and 100 kA at 400 V AC — the higher figure at 400 V means it handles fault currents in 400 V distribution without cascading upstream breakers. At 400 V rated value the spec is 50 kA; the AC at 400 V rated value is 100 kA, so the lower figure governs the thermal-magnetic trip curve while the higher one applies to the interrupting rating under AC conditions. The S3 frame (70 mm wide, 170 mm tall, 176 mm deep) leaves 70 mm clearance above and below, 10 mm at the sides for heat dissipation.
Main circuit terminals are screw-type, accepting 2x (2.5…16 mm²) solid or 2x (2.5…50 mm²) stranded, with a single conductor up to 70 mm². The front clamping point accepts 10 AWG only. Auxiliary contacts use M8 bolts. The screwdriver shaft is hexagonal socket, 4 mm tip size.
No ground fault or phase failure detection built in — this is a straight thermal-magnetic breaker for overcurrent and short-circuit protection only. An auxiliary switch can be added (product extension auxiliary switch: yes).