Who makes in-rack busbar & power whips for AI data centers

Busbar and power whips are the last stretch of power distribution inside the rack, carrying current from the power shelves (4.12) to each tray's own board-level power delivery (4.08). A solid or laminated busbar running vertically through the rack, rather than a bundle of individual cables, is what rack-scale systems use to move very high current at the ±48 V level the taxonomy specifies for NVL72-class racks; a bundle of discrete power whips remains the more conventional approach outside that specific architecture. The shift toward busbar reflects how much current a fully populated GPU rack now needs to distribute internally — a level that individual cables handle poorly at scale. For investors, this is a component defined by its current-carrying and thermal-management engineering rather than by exotic materials, and the suppliers building to the Nvidia-spec busbar are working from a reference design that's likely to be revised with each rack generation, which keeps requalification a recurring event rather than a one-time qualification.