The A9XPB812 is a cuttable comb busbar from the Acti9 range, wired for 3P+N distribution. It brings in power on one 4-pole way (3L+N) at 80 A, 40 °C, and splits it across 8 outgoing ways — each with its own neutral and phase, laid out as N N L2 N L3 per the distribution pattern. Rated operational voltage is 230 V AC phase-to-neutral or 400 V AC phase-to-phase at 50/60 Hz.
That figure assumes the busbar is mounted horizontally — the way it's designed to sit — and that the ambient inside the enclosure stays at or below 40 °C. Above that, you'd derate per the thermal curve (not supplied here, but standard for Acti9 gear). The insulation voltage of 440 V AC tells you the busbar is rated for the voltage stress between conductors in a 400 V system, with headroom for transients.
This busbar mounts horizontally on the bottom of tunnel-type terminals — it's not a DIN-rail clip part, it's a distribution bar that connects directly to the terminal blocks of the outgoing devices. The incomer pitch is 18 mm between phases; the outgoer pitch is 9 mm between phase and neutral, and 18 mm between phases. That 9 mm spacing matches the standard 1-module width of Acti9 MCBs and RCBOs, so each outgoing way lands cleanly on one device. The busbar is 218 mm wide, 30 mm deep, 30 mm tall — 12 modules in 18 mm increments. It's cuttable, so you trim it to the exact number of ways needed. Two end pieces are included to cap the cut end.