The Schneider Electric G12F4A16 is a GoPact MCCB 125 moulded-case circuit breaker, 4-pole, with a TM-D thermal-magnetic trip unit rated 16 A at 40 °C. It's built for distribution duty — Category A utilisation, meaning it's not intended for current-limiting selectivity but for straightforward branch-circuit protection in a panel. The LI protection curve covers overload (thermal) and short-circuit (magnetic) faults.
Mounts fixed to a backplate — no DIN rail adapter here. The 100 mm width, 130 mm height, and 60 mm depth fit the standard GoPact MCCB 125 footprint. Connection pitch is 25 mm, and both line and load connections are front-facing screw terminals, so it's panel-friendly for a wireman running conductors in a gland plate layout.
If your panel runs hotter, you'll need to derate — the thermal-magnetic element is temperature-sensitive. Electrical durability is 8000 cycles at 415 V In. Mechanical durability is 30000 cycles. Power dissipation per pole is 18.7 W. IP20 protection means it's touch-safe but not sealed against water or dust ingress — keep it inside the enclosure, not on the panel door. Operating altitude is 0–2000 m without derating; above that, up to 5000 m, you need to derate dielectric strength and breaking capacity per the standard.