The G12T3A20 is a Schneider Electric GoPact MCCB 125 molded case circuit breaker, 3-pole, rated 20 A at 40 °C with a TM-D thermal-magnetic trip unit. The fixed-mount design with front-connect screw terminals and a 25 mm pole pitch suits standard backplate mounting — no DIN rail adapter needed.
That is the number to match against your load's full-load amps — not a higher 25 °C rating some breakers list. For a 415 V distribution panel with an available fault current below 10 kA, this breaker is a direct fit. Above that, you need a higher-rated frame or a current-limiting upstream device. IP20 finger-safe terminals are standard; the breaker itself is not sealed against washdown.
Integration notes
The 75 mm width (3 × 25 mm pole pitch) and 130 mm height fit standard MCCB cutouts in panel enclosures. Screw terminals accept copper or aluminium conductors; torque values per the manufacturer's installation sheet. The toggle handle protrudes from the front; allow clearance for manual operation and padlocking. Power dissipation is 18.7 W per pole at rated current — 56.1 W total for the 3-pole unit. That heat must be considered in the enclosure thermal budget, especially when multiple breakers are ganged in a panel. Ambient operating range is -20 to 55 °C; storage range -35 to 85 °C.