It carries a continuous rated current of 1 A and a Trip Class 10, so it will disconnect within 10 seconds at 7.2× rated current, which is the standard for protecting motor and transformer circuits against overload.
Breaking capacity and fault clearing
The 3RV1421-0JA15 delivers 100 kA breaking capacity across the board — at 240 V, 400 V, 500 V, and 690 V AC. For a transformer primary circuit, this level of SCCR (short-circuit current rating) gives you headroom to coordinate with upstream fuses or a main breaker, keeping selectivity simple.
Auxiliary contacts and control wiring
The breaker accepts an auxiliary switch (product extension available) that mounts transversely. The auxiliary contact ratings are 1 A at 24 V, 0.5 A at 230 V, and 0.15 A at 60 V — these are the switching capacities for the signal contacts, not the main circuit. For control wiring, the screw terminals accept solid conductors from 0.5 to 1.5 mm² (two per terminal) or stranded from 1 to 2.5 mm². The main circuit terminals take AWG 14–10. The breaker itself draws no control power; the 7.25 W power dissipation at AC-3 hot operating state is heat that needs to be considered in a dense panel.
The breaker meets RoHS and REACH substance restrictions, with a substance prohibition date of 01.05.2012 — meaning it has been compliant since that date.