The G12E4A63 is a 4-pole GoPact MCCB 125 molded case circuit breaker from Schneider Electric, fitted with a TM-D thermal-magnetic trip unit rated 63 A at 40 °C. The TM-D provides LI protection — a thermal element for overload (L) and a magnetic element for short-circuit (I) — which is the standard combination for distribution feeder and branch circuits where you need adjustable thermal pickup but fixed magnetic instant trip. The 4D protected poles configuration means all four poles — three phases plus the switched neutral — are protected by the trip unit, with neutral protection set at 1 x Ir. This is the configuration you want for a 4-wire distribution system where the neutral is not bonded to ground downstream and needs its own overcurrent protection.
Where it is used and deployment context
This is a distribution-class MCCB — it lives in a main or sub-distribution panel, typically on a backplate inside an IP20 enclosure, protecting a 63 A feeder or a large branch circuit. It can be mounted horizontally or vertically flat on the back, which gives panel builders flexibility in tight layouts.
The Annex H reference covers EMC requirements for circuit-breakers with electronic overcurrent protection — relevant if your panel must pass an EMC audit. The 440 V AC rated insulation voltage and 415 V AC operational voltage confirm it is a 400 V class device for 50/60 Hz networks.