The Schneider Electric G12T3A125 is a GoPact MCCB 125 — a 3-pole, 125 A molded-case circuit breaker with a TM-D thermal-magnetic trip unit. Breaking capacity is 10 kA at 380/415 V AC, which is the fault-clearing ceiling for this frame — sized for standard commercial and light industrial distribution panels where fault currents stay under that threshold. Rated operational voltage is 415 V AC 50/60 Hz, with an insulation voltage of 440 V AC.
Fixed-mount design for backplate installation. Accepts both horizontal and vertical orientations, flat on the back. Dimensions: 130 mm high, 75 mm wide, 60 mm deep.
Durability and environment
Mechanical durability is 30,000 cycles; electrical durability is 5,000 cycles at rated current and 415 V. Power dissipation per pole is 18.7 W — useful for thermal budget calculations in a sealed enclosure. Operating temperature range is -20 to 55 °C, storage range -35 to 85 °C. Altitude derating: no derating up to 2,000 m, derating required from 2,000 to 5,000 m.