Open Rack V3 Meta AC WHIP Power Cable, Revision 1.0 (May 2022)

Overview

The document states that the ORV3 AC whip design is fully open and that lessons learned in development are built into the specification. The core principle is to eliminate the PDU that ORV2 used for power distribution; many PDU functions have moved into the ORV3 power shelf, which the document says increases power delivery efficiency for the rack and reduces voltage losses and potential failure points. The whip accepts 3-phase WYE input (4 wires plus ground) and connects to the ORV3 power shelf through an overmolded OCP 7-pin universal input connector. There are two basic versions: 277/480 VAC, 20 A NEC assembly with an L22-20P plug for North America, and 200-240/346-415 VAC, 32 A IEC assembly with an IEC 309 plug for IEC applications.

Electrical requirements follow the input and cord. NEMA input is a nominal maximum continuous 20 A per phase (16 A after 80% derating) at 45 C ambient. IEC input is 32 A per phase, again at 45 C ambient; the IEC 309 plug is 5-pole (3P+N+E) with earth at 180 degrees / 6h and no IP67 cover. The North American cord is SOOW (preferred for the flexibility of its rubber jacket) or STW 12 AWG 5-conductor; the EU cord is H07RN-F 5G4 or 5G6, with 6 mm2 recommended for electrical and safety reasons and 4 mm2 acceptable where routing in the rack makes 6 mm2 infeasible. On the output side a Positronic SP10RSSS1F0001/AA-2268 connector and matching crimp contacts are used.

The mechanical section defines 7 length variations: for the top, middle and bottom power-shelf positions the NEMA whip is 1600, 2700 and 3800 mm and the EU whip 2100, 3200 and 4300 mm, plus a 4500 mm special use case. The connector hood can be a screw-on/snap-on plastic hood or a custom overmold, which Meta prefers for reliability (maximum 24 mm height, 23 mm for the plastic hood). The cable ideally exits the housing parallel to the rear wall of the power shelf (90 degrees), with 100 degrees maximum. Both faces must carry the label 'Not for current interrupting. Do not hot plug.'

The compliance and test section asks for UL RU recognition (or an equivalent NRTL) to UL/CSA 62368-1 and CE certification, with UL 1682, UL 498, UL 1977, UL 62/UL 817 and EN 50525 for parts. Tests are a cord pull of 100 N x 1 s x 25 times (conductor displacement at most 2 mm), 5000 VDC dielectric strength for at least 90 s, 25 insertion cycles, contact temperature rise not above 30 C (IEC 60512-5-1), 100% production hi-pot (1500 VAC rms or 2121 VDC) and a polarity test. The environment is -5 to +45 C and 3000 m without derating. This revision covers only the 20 A and 32 A class; the 60 A whip is a separate specification.

Key points

1. The whip feeds an ORV3 power shelf directly from the facility 3-phase WYE supply without a rack PDU; PDU functions move into the shelf, reducing voltage losses and potential failure points.
2. Two WYE variants: 277/480 VAC 20 A NEC assembly with NEMA L22-20P plug (North America) and 200-240/346-415 VAC 32 A IEC assembly with IEC 309 plug.
3. The whip terminates in the OCP 7-pin Universal Input Connector (Positronic SP10RSSS1F0001/AA-2268) on the ORV3 power shelf and comes in 7 lengths for different shelf positions.
4. NEMA input: nominal maximum continuous 20 A per phase (16 A after 80% derating) at 45 C ambient.
5. IEC input: 32 A per phase at 45 C ambient; IEC 309 plug 5-pole 3P+N+E with earth at 6h (180 degrees), no IP67 cover required.
6. NA cord SOOW (preferred) or STW 12 AWG 5-conductor; EU cord H07RN-F with 4 mm2 or 6 mm2 conductors, 6 mm2 recommended.
7. Lengths (top/middle/bottom): NEMA 1600/2700/3800 mm, EU 2100/3200/4300 mm, plus a 4500 mm special use case.
8. Cord pull test 100 N x 1 s x 25 times plus 0.25 N-m torque; conductor displacement at most 2 mm; dielectric strength 5000 VDC for at least 90 s; 25 insertion cycles.
9. Contact temperature rise at maximum current must not exceed 30 C (IEC 60512-5-1); 100% production hi-pot at 1500 VAC rms or 2121 VDC.
10. Operating environment -5 to +45 C, 10-90% RH, 3000 m without derating; connector label 'Not for current interrupting. Do not hot plug.' is mandatory.

Using it in design

• Add ORV3 whip feed types (NA 277/480 V L22-20P 20 A, EU 400 V IEC 60309 32 A) to the power-distribution catalogue so busway tap-off and receptacle schedules can be generated per rack.
• In per-rack capacity checks use 16 A continuous for NA 20 A whips (80% rule) and the 45 C ambient rating, which applies to hot-aisle and rear-of-rack temperatures.
• Omit the rack PDU from ORV3 rack bills of materials when whips are used.
• In rear-of-rack cable routing account for the 90 degree cable exit and for choosing length by power shelf position (top, middle, bottom).
• Put UL RU recognition and CE, UL 1682/UL 498/UL 1977 part certificates, 100% hi-pot and polarity testing and T-rise and pull test reports in the procurement specification.
• Verify separately the whip's -5 to +45 C operating limit for designs where rack-rear temperatures may exceed 45 C.

Who should read it

Electrical engineers designing AC feeds for ORV3 racks, cable and connector suppliers and rack integrators.

Document contents

1. License
2. Acknowledgements
3. Compliance with OCP Tenets
4. Version Table
5. Scope
6. Overview
7. Electrical
8. Basic Functional Schematic
9. Input
10. NEMA
11. IEC
12. Power Cord
13. Output
14. Output Connection
15. Output Polarity
16. Mechanical
17. Cable Lengths
18. Connector Housing Hood
19. Plastic Hood
20. Overmolded Hood
21. Cable Exit from Housing
22. Wire Splitting
23. Safety Warning Label
24. Assembly Label
25. Regulatory Compliance Approvals
26. Agency Approval
27. Safety Design Considerations & Testing
28. Production Line Test
29. Environmental Regulations & Requirements
30. Reliability, Quality, Miscellaneous
31. Mechanical Drawings
32. Appendix A - Checklist for IC approval of this Specification

Related standards

• OCP Open Rack V3 Power Shelf Specification
• IEC 60309
• NEMA WD 6 (L22-20)
• NFPA 70 (NEC)

Read the document

Publication details

Authors

Shapiro, D.; Kim, B. (Meta)

Publisher

Open Compute Project Foundation

Year

2022

Document number

Rev 1.0

Document language

English

Source type

Industry body

Access

Open licence — downloadable

Licence

OWFa 1.0 — Open Compute open specification licence; redistribution permitted

Licence evidence

www.opencompute.org

Citation