The G12E4A40 is a 4-pole GoPact MCCB 125 rated 40 A at 40 °C with a TM-D thermal-magnetic trip unit. The 4D protected poles and neutral protection set at 1 x Ir mean the neutral pole is fully rated and switched — essential for 4-wire systems where you need to isolate the neutral. The utilisation category A tells you it is not intended for motor starting duty (cable/transformer protection, not switching motor inrush).
Fixed mounting on a backplate — this is not a DIN-rail snap-on breaker. You bolt it to a mounting plate in the enclosure. Screw terminals front and back mean you land cables from above and below, which keeps the wiring layout clean in a panel. The IP20 finger-safe enclosure is fine inside a locked cabinet but not for washdown areas. Mount it horizontally or vertically flat on the back — no restriction on orientation for thermal performance at 40 A. Overvoltage category III confirms it is designed for fixed-installation distribution boards, not for equipment-level protection.
The 8000-cycle electrical endurance at 415 V In and 30000-cycle mechanical endurance are typical for a distribution MCCB — it is not a high-cycle switching device. For a panel that sees a few operations per day, that endurance covers decades.
The 440 V rated insulation voltage and 415 V operational voltage at 50/60 Hz cover standard 400 V three-phase networks. The grey RAL 7035 colour is the standard industrial enclosure shade — matches other switchgear in the cabinet.