VDC · Volts direct current
The unit naming rack and facility DC-bus architectures, whose higher levels delete conversion stages and copper at the cost of new protection and grounding engineering.
Current numbers
~600 kWper Rubin Ultra Kyber rack (NVL144: 144 GPU packages) on 800 VDC
NEC 2029 (partial, forecast); UL certification pathway openNEC 2029 expected to add partial 800 VDC provisions (SemiAnalysis); UL opened an MV SST certification program in September 2026
840 VDCOCP LVDC white paper v1.1.0 proposal: highest protection voltage (U5) an 800 VDC source must not exceed