The Schneider G12T3A100 is a GoPact MCCB 125 fixed-mount circuit breaker, 3-pole, rated 100 A at 40 °C with a TM-D thermal-magnetic trip unit. It's a Category A distribution breaker designed for 415 V AC 50/60 Hz systems, with a 10 kA breaking capacity at 380/415 V AC.
The TM-D trip unit gives you LI protection: thermal (L) for overload and magnetic (I) for short-circuit. The thermal element tracks heating in the conductor, so at 100 A continuous it holds; above that, it follows an inverse-time curve. The magnetic pickup is fixed and instantaneous — it clears a hard short before the wire can melt. Mounts on a backplate, screw terminals front-connected both top and bottom. The 25 mm connection pitch matches standard busbar or cable-lug spacing. It's rated IP20 — fine inside a closed panel, not for washdown areas. The 8000-cycle electrical durability at rated current and 415 V AC is solid for a distribution breaker — you're not cycling it daily like a motor-starting contactor, but it handles occasional switching for isolation or maintenance. The 30000 mechanical cycles cover panel reconfigurations over its service life.
Deployment context
This breaker lives on a backplate inside an enclosure — typically a distribution board or a motor control center. The front-connect screw terminals make it straightforward to wire with lugs or busbars. It's rated for isolation per EN/IEC 60947-2, so you can use it as a visible-break disconnect for safe maintenance downstream.