The Layer 4/5 interface. Where the sidecar power rack meets the IT rack 48V busbar. Is the connector-engineering choke point of the AI-density facility. 400+ ampere continuous current at 48V DC. Blindmate operation required. Failure mode is fire. Three vendors dominate (TE Connect
The sidecar power rack is the specific Layer 4 architecture that OCP Mt. Diablo (v0.7.0, March 2026) established as the reference for hyperscaler AI-density deployments. Physical separation of rack-level power conversion (800V DC to 48V DC) from the IT compute rack. Enables specialised thermal
The solid-state transformer (SST) is consequential piece of equipment in the 800V DC architecture. Four Western vendors (Eaton, Schneider, ABB, Hitachi Energy) plus three credible Chinese entrants (CRRC, BYD, TBEA) constitute the entire universe. Silicon carbide device concentra
800V DC is not the endpoint. Layer 2 (perimeter conversion) faces a specific voltage-ceiling decision that will shape 2028-2032 facility architecture: hold at 800V, step to 1500V DC, or reach for MVDC at 5-15 kV. Each has different copper savings, standards readiness, vendor availability, and r
The pure-DC facility is a specific edge case. Most operational data centres will run zoned hybrid architectures. Parallel AC and DC infrastructure. Through 2035 and beyond. Hyperscaler strategies diverge on this: Meta and Google adopt architected zones. Microsoft site-by-site. AWS
The capex premium for 800V DC architecture is not concentrated in any one layer. It accumulates across all six of the power stack. Cooling infrastructure (Layer 5) carries the largest single-layer premium at $90M for 100 MW greenfield. Layer 2 (perimeter conversion) second at $45M. Total transi
800 VDC becomes the default architecture for new AI infrastructure builds above 100 MW by 2028-2029. Installed-base composition reaches 60 percent DC by 2035. 1500 VDC under active discussion for 500 MW+ facilities. Five specific risks + five specific predictions with named catalysts.
Commissioning at 800 VDC runs 40-60 percent longer than AC baseline. Skills gap requires 80-120 hours retraining per electrician at $8-15K. Pipeline capacity (Vertiv Academy, Schneider EU, Eaton EU, IBEW apprenticeship, university programmes) falls short of estimated 2028 demand by roughly 5,00
48V incumbents face 20-40 percent revenue-at-risk. Vertiv/Eaton/Schneider win through content-dollar expansion 2-3x per rack. WBG semi content grows 3-4x. New entrants (Menlo Micro SSCB, Skeleton HSC, Submer immersion) emerge in specialty niches. Layer-specific screening beats sector-level.
OCP fastest (Mt. Diablo published May 2025, 80+ ecosystem partners). IEC leads on protection (IEC 60947-10 for SSCBs published early 2026). NEC and IEEE trail 24-36 months. Full convergence 2028-2029. Interim projects carry 8-15 percent multi-standard compliance premium.
800 VDC facilities present different power-quality profiles to the utility grid than legacy AC. Rectifier topology choice at Stage 1 determines whether the facility passes the interconnection study or bounces. ERCOT and PJM regulatory posture is tightening.
Above 100 kW per rack, 800 VDC and direct-to-chip liquid cooling are not independent decisions. Air cooling caps at 40-60 kW per rack. Vendor consolidation (Vertiv/PurgeRite $1B, Eaton/Boyd $9.5B, Schneider/Motivair $1.7B) happened because customers want both from one vendor.