The G12T3A25 is a 3-pole GoPact MCCB 125 moulded-case circuit breaker with a TM-D thermal-magnetic trip unit rated 25 A at 40 °C. The 10 kA breaking capacity at 380/415 V AC (performance level T) tells you it can safely interrupt a fault current up to 10 kA without welding contacts or cascading upstream; that covers most distribution panels fed by a 500 kVA or smaller transformer. The 440 V AC rated insulation voltage (Ui) and 415 V AC rated operational voltage (Ue) at 50/60 Hz match standard European low-voltage distribution.
Fixed backplate mounting, screw terminals front-connected both sides. IP20 finger-safe terminals — fine inside a locked panel, not for outdoor or washdown zones. The toggle handle gives local manual switching and a clear visual trip indication.
Protection and durability notes
The magnetic trip is fixed, not adjustable — it clears hard faults fast. Electrical endurance is 8000 cycles at rated current and 415 V; mechanical endurance 30 000 cycles. Power dissipation is 18.7 W per pole — plan for heat rejection inside the enclosure if you load all three poles near 25 A.