Open Rack V3 Base Specification, Revision 1.0

Overview

The document defines the technical requirements for all components of the Open Rack V3 family so that IT gear is intermateable across racks and power systems. Revision 1.0 was released to the community on 22 September 2022 (0.1 in June 2022, 0.2 on 24 August 2022). Requirements use SHALL (mandatory), SHOULD (recommended) and MAY (optional for interoperability). There are no formal external dimensions (depth, height, width), which are left to the rack developer, who must consider shipping packaging and doorway limits. Many dimensions appear only in figures.

The mechanical chapter offers two frame geometry options. Option 1 supports a 48 mm vertical OpenU pitch or, optionally, the 44.45 mm EIA-310-D rack unit pitch. The 48 V busbar cross-section and the bar interfaces in the rack bottom plate and top canopy are standardised; the conductive busbar surface must have a continuous path to the frame that passes rust grade 6 per ASTM D610 after 48 hours of ASTM B117 salt spray. Side-panel support features and optional stabiliser interfaces are defined, and screw holes are specified for M5 and M6 thread-forming screws with a minimum strip-out torque of 6.25 N-m.

For racks with casters, all four swivel 360 degrees and stay within the rack envelope; the rack must have a ramp entry angle of at least 10 degrees and exit angle of at least 15 degrees. Leveling feet must lift the casters at least 15 mm, have a swivel foot of at least 30 mm diameter, operate at no more than 25 N-m when fully loaded and stay within the footprint. Tests include a 4 mm step, a 25.4 mm floor gap, a 5-degree ramp, a 19 mm roll-off and 800 m of rolling at 0.8 m/s; afterwards push force must be below 5% of combined rack and IT weight. A 10-degree tilt test also applies.

Environmental limits: operating 10-60 C, long-term storage -40 to 50 C at 5-95% RH, short-term storage -20 to 65 C at 10-80% RH, operating humidity at most 85% with a 5 C minimum dew point. Grounding requires M5x0.8 nut features to mate with a telco ground lug, ground points that pass rust grade 6, and a supplemental conductive path from IT equipment to the rack lug that avoids unprotected surfaces; ground points are on the top surface (overhead) and the rear base (underfloor). Regulatory items include IEC 62368-1 CB certification, UL 62368-1, CE, RoHS, REACH and UL94 V-0 plastics.

The electrical chapter defines IT gear input by two options: nominal 51 VDC (gear must operate normally from 46-52 V) or nominal 54 VDC (52-56 V). The IT gear input connector has four connections: power path 100 A continuous, ground path 100 A continuous, chassis ground 65 A for 2 minutes and power sense 1.5 A continuous. The document covers the rack frame and the IT interface, not the power shelf itself, which has its own OCP specification.

Key points

1. Revision 1.0 was released on 22 September 2022; external dimensions (depth, height, width) are deliberately not specified.
2. The rack supports 48 mm OpenU or 44.45 mm EIA-310-D rack unit pitch.
3. Racks with casters need at least a 10 degree ramp entry angle and a 15 degree ramp exit angle; four casters swivel 360 degrees within the rack envelope.
4. Leveling feet must lift casters at least 15 mm, have a swivel foot of at least 30 mm diameter and need at most 25 N-m of torque when fully loaded.
5. Frame environment: operating 10-60 C, humidity at most 85% with 5 C minimum dew point, long-term storage -40 to 50 C at 5-95% RH.
6. Rolling tests include a 4 mm step, 25.4 mm floor gap, 5 degree ramp and 800 m at 0.8 m/s; afterwards push force must be under 5% of total rack plus IT weight.
7. Power shelf input option 1 is nominal 51 VDC with IT gear operating from 46-52 V.
8. Option 2 is nominal 54 VDC with a 52-56 V range; the IT connector is rated 100 A continuous on power and ground paths, 65 A for 2 minutes on chassis ground and 1.5 A on power sense.
9. Ground points are on the top surface (overhead) and rear base (underfloor) and must pass rust grade 6 per ASTM D610 after 48 hours of salt spray.
10. Regulatory requirements: IEC 62368-1 CB, UL 62368-1, CE, RoHS, REACH and UL94 V-0 or better plastics.

Using it in design

• In rack delivery and placement planning, check the 10-degree entry and 15-degree exit ramp angles, the 25.4 mm floor gap and the 4 mm step as rolling limits, and obtain door and shipping dimensions from the rack vendor separately.
• Plan underfloor and overhead grounding conductors around the rack's ground points (top and rear base) and verify the ASTM D610 rust-grade requirement with the supplier.
• Compare the hall's temperature and humidity design range with the rack's operating envelope (10-60 C, 85% maximum humidity, 5 C minimum dew point).
• Decide between the 51 VDC (46-52 V) and 54 VDC (52-56 V) options with the power shelf and IT gear suppliers, and check busbar and cable voltage drop against the 100 A class connector.
• For seismic zones, write the requirement that leveling feet support the fully loaded rack under seismic test conditions into the specification, together with the manufacturer's or operator's definition of those conditions.

Who should read it

Hardware engineers designing ORv3-compatible racks, IT gear and power shelves, and data centre designers deploying ORv3 racks.

Document contents

1. License
2. OCP Tenets Compliance
3. Revision Table
4. Scope
5. Overview
6. Mechanical
7. Rack Geometry Option 1
8. Rack Geometry Option 2
9. Busbar (48V busbar geometry, ground path, center busbar interfaces)
10. Stabilizer Interfaces
11. Side Panel
12. Caster Requirements
13. Leveling Feet
14. Fastener Requirements
15. Environmental Requirements
16. Color and Marking
17. Electrical Grounding
18. Environmental and Regulations
19. Testing (rolling movement, unpackaged tests)
20. Electrical Requirements for IT Gear (input voltage, power sequence, voltage sense)
21. References
22. Appendix A - Requirements for IC Approval

Related standards

• OCP Open Rack V3
• EIA-310-D

Read the document

Publication details

Authors

Glenn Charest; Steve Mills; Loren Vorreiter

Publisher

Open Compute Project Foundation

Year

2022

Document number

ORV3 Base Spec Rev 1.0

Document language

English

Source type

Industry body

Access

Open licence — downloadable

Licence

OCPHL-P — OCP hardware licence; redistribution permitted

Licence evidence

www.opencompute.org

Citation