800 VDC Architecture: Industry Alignment & Execution

Overview

This follow-up moves from the abstract argument to buildable configurations. Its roadmap lists four generations: Gen 1 power racks up to 145 kW (60 A whips, 8-to-make-6), Gen 2 (Vera Rubin NVL72) at 330 kW per rack, Gen 3 with 100% liquid-cooled power shelves up to 570 kW per rack position, and Gen 4 native 800 VDC. The current AC baseline (DSX) uses 480 VAC distribution, 100 A AC whips and 4-to-make-3 rack feed redundancy.

Option A is the rack-level Power Rack feeding adjacent compute racks: about 660 kW per power rack, 12 x 100 A IEC 60309 whips at 415-480 VAC (no neutral), six 18.3 kW PSUs per shelf and 125 A 800 VDC cables to the compute racks, with production planned for Q3 2026. The BBU variant has four 20 kW BBUs supporting 80 kW for 60 seconds, and each PSU holds 1200 J for input current shaping.

Option B is a row/cluster Power Center: up to 2 MW output, preferably 1250 A aggregated feeders and an overhead 800 VDC busway with 125 A tap cans (MCCB or SSCB). MCCB clearing can take up to about 20 ms, so feed redundancy or holdup is needed. Option C is the hall-level DC Power Block of about 4.8 MW (or ~1.6 MW Power Centers in 4-to-make-3), with 6000 A-class DC busduct, 1250 A row busways and 4+1 block redundancy with a catcher.

The paper also treats DC fault behaviour, grounding and protection zoning, insulation monitoring and arc-flash work. The in-rack 800 VDC to 54 VDC shelf uses six 15 kW PSUs and certification leans on UL 62368-1. Rack-level peak shaving with small local storage is presented as the way to show upstream systems a steady load. The figures reflect NVIDIA's product plans and are not independently field-verified.

Key points

1. Roadmap: 145 kW (Gen 1), 330 kW (Vera Rubin NVL72), 570 kW per rack position (Gen 3, fully liquid-cooled), Gen 4 native 800 VDC.
2. AC baseline: 480 VAC, 100 A whips, 4-to-make-3 rack feed.
3. Option A Power Rack: ~660 kW, 12 x 100 A whips, 6 x 18.3 kW PSUs per shelf, 125 A 800 VDC cables; production Q3 2026.
4. BBU option: 4 x 20 kW supporting 80 kW for 60 s; 1200 J per PSU for input current shaping.
5. Option B Power Center: up to 2 MW, 1250 A feeders, 125 A tap cans; MCCB clearing up to ~20 ms.
6. Option C DC Power Block: ~4.8 MW, 6000 A-class busduct, 1250 A row busways, 4+1 redundancy with catcher.
7. In-rack 800 VDC to 54 VDC shelf: 6 x 15 kW PSUs, UL 62368-1 certification path.

Using it in design

• Define four electrical templates for AI halls: AC baseline (480 VAC, 100 A whips, 4M3), Power Rack, 2 MW Power Center and 4.8 MW DC Power Block with 4+1 catcher.
• Check DC breaker clearing time (~20 ms) against rack holdup.
• Validate busway and tap-can ampacity against rack kW at 800 V.
• Add insulation-monitoring and DC arc-flash study tasks to the project checklist.
• Drive per-row power planning from the rack generation (145/330/570 kW).

Who should read it

Electrical designers, AI hall architects and campus power managers planning an 800 VDC transition.

Related standards

• UL 62368-1
• IEC 60309
• NFPA 70E

Publication details

Authors

Jared Huntington; Mike Tu

Publisher

NVIDIA

Year

2026

Document language

English

Source type

Manufacturer

Access

Free to read

Licence

Copyright retained; citation only — the publisher’s terms apply to the original document

Citation