A concise guide to the 48VDC Open Rack v3 power architecture: rack-level busbar, power shelves & rectifiers, battery backup (BBU), and how AC inputs and IT loads tie in.
Open Rack v3 (ORV3) is a 48V rack power standard from the Open Compute community. It centralizes power at the rack using a rear busbar fed by power shelves/rectifiers and optional battery backup units, delivering higher efficiency and density versus traditional AC at the device level.
Rack-length DC distribution rail providing blind-mate power to IT sleds and accessories.
Convert incoming AC (or HVDC) to regulated 48VDC for the busbar; hot-swappable rectifier modules.
Rack-level energy storage for ride-through; coordinates with rectifiers and facility UPS/gensets.
| Item | ORV3 (48VDC) | Traditional (AC to each device) | Notes |
|---|---|---|---|
| Conversion | Central rectifiers → busbar | PSU in every device | ORV3 reduces duplicated conversion losses |
| Redundancy | Rack-level N+1/N+N rectifiers & BBU | Dual PDUs & dual PSUs per device | Both viable; strategies differ operationally |
| Cable Management | Blind-mate sleds; fewer AC whips | Many C13/C19 cords per rack | ORV3 can improve airflow/serviceability |
Implementation details vary by vendor; always follow the specific ORV3 platform documentation and facility standards.
For high-draw IT gear and power shelves that still present AC inlets.
Rack/shelf AC inputs matched to site voltage and phase.
Heavy-gauge DC cabling, lugs, and accessories for busbar tie-ins.
Pre-labeled sets, color-coded conventions, documentation for deployment.
Yes. Many sites operate hybrid rows. Plan your feeds, labeling, and spares accordingly to avoid confusion between 48V DC busbar racks and AC-only racks.
ORV3 platforms typically use sleds designed for 48V busbar input (no device-level AC PSU). Follow your platform vendor for compatibility and options.