What it is and what it does
The Siemens 3RV1421-1JA10-ZX95 is a SIRIUS circuit breaker specifically designed for transformer protection, carrying a continuous current rating of 10 A and a Trip Class 10 characteristic. Rated insulation voltage is 690 V, and the breaking capacity reaches 100 kA at 400 V AC, 100 kA at 240 V AC, 42 kA at 500 V AC, and 6 kA at 690 V AC — figures that determine the maximum fault current it can safely interrupt at each voltage level. Phase failure detection is built in, and the unit is three-pole for main current circuits, with screw-type terminals on both main and auxiliary/control circuits.
Mounting and integration
Fastening is via screw and snap-on mounting onto a 35 mm standard mounting rail per DIN EN 50022; mounting position is any, so it fits in tight panel layouts without orientation restrictions. Dimensions are 45 mm width, 97 mm height, and 96 mm depth, with zero clearance required at the back or sides — useful when packing multiple units on a DIN rail in a crowded enclosure. Front protection class is IP20; the housing is finger-safe for touch protection against electrical shock, which matters for panel access without full de-energization during troubleshooting.
Environmental and compliance
Lifecycle stage is current production — this part is still in active manufacture per the manufacturer's status. Operating temperature range is -20 to +60 °C; storage and transport range is -50 to +80 °C. Shock resistance is 25 g for 11 ms. RoHS compliance date is 01.05.2012; the part is free of substances prohibited under that directive as of that date.
Termination and wiring
Main circuit terminals accept solid or stranded conductors: 2x (1 to 2.5 mm²) and 2x (2.5 to 6 mm²), with AWG equivalents of 2x (14 to 10). Finely stranded with core end processing uses the same ranges. Power dissipation at AC in hot operating state is 9.25 W total, or 3.1 W per pole — a figure to check against enclosure thermal budgets when grouping multiple breakers.