Power shelves in AI racks and the move to 800 V DC
See how power shelves feed an NVL72-class rack, which listed companies make them and the chips inside, and what NVIDIA’s 800 V DC partner lists establish.
Hot-swap rectifier modules of several kilowatts each, grouped in 1U shelves, that turn facility AC into roughly 50 V DC for the busbar.
What does a power shelf do?
It converts facility AC into DC for the rack’s busbar. NVIDIA’s DGX guide describes about 120 kW per rack from eight power shelves of six air-cooled 5.5 kW supplies in N+N redundancy, converting AC to a nominal 50–51 V DC, and the busbar carries up to 1,400 A to the trays. Vertiv’s PowerDirect 3000 is such a shelf: 33 kW from six hot-swap 5.5 kW supplies for GB200 and GB300 platforms. In GB300 NVL72, capacitors fill about half of each power supply’s volume and store 65 J per GPU; with power caps and a hardware power burner, NVIDIA measured 30% lower peak grid demand in a training test.
Who makes the shelves and the chips inside?
NVIDIA says the GB300 NVL72 power supply’s energy storage was co-designed with Lite-On, the one current-rack power attribution NVIDIA makes, and Lenovo’s GB300 guide lists Delta and Lite-On as power-supply options. Vertiv sells its 33 kW shelf for GB200 and GB300; Delta, Flex and Advanced Energy sell AI power shelves; and Murata reports rising sales of server power supplies. Inside the supplies, GaN, SiC and control chips come from companies such as Texas Instruments, onsemi, Infineon, Navitas, Power Integrations, STMicroelectronics and ROHM, all on NVIDIA’s 800 V DC silicon lists, as is the private Efficient Power Conversion. Which chips sit in a given shelf is not disclosed, and press reports of shelf suppliers for specific deployments are not used.
What changes with 800 V DC?
NVIDIA says a 1 MW rack at 54 V would need up to 200 kg of copper busbar and that power shelves would take up to 64U of a megawatt Kyber rack, so it plans 800 V DC distribution with DC/DC conversion in the rack, reaching full-scale production with Kyber in 2027. Suppliers are preparing: Delta showed 660 kW in-row power racks of six 110 kW shelves with embedded battery backup, Flex an 800 VDC power rack for Vera Rubin, and TI an 800 VDC architecture with NVIDIA that includes a 30 kW 800 V AC/DC supply. NVIDIA’s May and October 2025 posts list silicon, component and data-center power partners for that generation; they name no suppliers, volumes, prices or shares for today’s GB200 or GB300 racks.
How to research a rack power company
Name the generation: in-rack shelves at about 50 V for GB200 and GB300, or 800 V DC power racks and DC/DC converters for later platforms.
Separate the shelf or supply maker from the semiconductor companies inside it, and both from facility power equipment outside the rack.
Read NVIDIA’s 800 V DC lists as a roadmap: a listed company is preparing products for that generation, not shipping them in current racks.
Check corporate changes: Flex agreed to acquire EPC Power and plans to spin off its Cloud and Power Infrastructure segment in Q1 2027, which would move much of this exposure to a new listing.
Check the business mix: Delta, Lite-On and Murata are diversified groups, so an AI power product may be a modest part of revenue.
Use the list as a starting point: it is curated, not exhaustive, and the model is illustrative, not a bill of materials.
Capacitors fill about half of the GB300 power supply’s volume and store 65 J per GPU; energy storage co-designed with Lite-On; 30% lower peak grid demand in a training test.
Up to 200 kg of copper busbar for a 1 MW rack at 54 V; shelves would take up to 64U of a megawatt Kyber rack; full-scale 800 VDC production with Kyber in 2027; the first partner lists.
Partner-disclosed: NVIDIA’s technical blog says the GB300 NVL72 power supply’s energy storage was co-designed with LITEON; Lite-On’s GTC 2026 release covers its 800 VDC power rack, shelves and CDUs.
Disclosed: Vertiv’s product page names the PowerDirect 3000 shelf for GB200 and GB300, and its release describes a GB300 NVL72 reference architecture; NVIDIA lists Vertiv among 800 VDC partners.
Disclosed: Delta’s GTC 2026 release and data-center catalog describe power shelves, BBUs, cold plates and CDUs for NVIDIA platforms, including a GB300 NVL72 in-rack CDU; NVIDIA lists Delta among its 800 VDC partners.
Disclosed: Flex’s release describes its 800 VDC Power Rack for NVIDIA Vera Rubin, and its Sept 2026 8-K lists power shelves, PDUs, cold plates, manifolds and CDUs; NVIDIA names Flex as an 800 VDC partner.
Disclosed: Infineon’s August and June 2026 releases describe AI data-center power as its main growth driver and a €2.5 billion FY2027 AI revenue projection; NVIDIA names it among 800 VDC partners.
Facility-scale power conversion (MW-scale rectifiers, energy storage, solid-state transformers) that Flex agreed to acquire for $4.4 billion (Sept 3, 2026; closing expected Q4 2026). It is unrelated to Efficient Power Conversion.