Meeting the Demands of Flexible Data Center Design
Legrand
Legrand argues that flexibility is the design principle that best supports change over a data centre's life, and applies it to the cabinet and the rack PDU. Its main concern is why PDU mounting brackets so often delay installations.
On this page
Overview
The paper states that racks are often replaced at refresh because they cannot accommodate new equipment form factors, and that cabinets carry thousands of pounds of equipment on footprints as small as 600 mm x 1000 mm. These two observations frame cabinet and PDU choice as a lifecycle decision.
On the electrical side, busway and three-phase rack PDUs with alternating-phase and combination outlets are presented as flexible infrastructure that lets racks be repopulated. Combination C13/C19 outlets accept both C14 and C20 plugs, easing future IT refreshes, and the alternating-phase layout supports three-phase balancing. Intelligent rack PDUs can shed non-critical loads in a predefined priority order on main-source failure.
The weight of the paper is on mounting. PDU brackets are described as a frequent cause of installation delay, and five common configurations are listed: single facing inside, double facing inside, single facing outside, double facing outside and quadruple facing inside. The remedy offered is toolless, vertically adjustable PDU mounting in the cabinet frame. As a vendor white paper, the remedy points to Legrand's own approach and gives no comparative numeric data.
Key points
- Combination C13/C19 outlets accept both C14 and C20 plugs, easing IT refreshes.
- Alternating-phase outlet layout supports three-phase balancing.
- Intelligent rack PDUs can shed non-critical loads in a predefined priority order when the main source fails.
- Cabinets carry thousands of pounds of equipment on footprints as small as 600 mm x 1000 mm.
- Five common PDU configurations: single/double facing inside, single/double facing outside, quadruple facing inside.
- Racks are often replaced at refresh because they cannot take new equipment form factors.
Using it in design
- In the cabinet catalogue record supported PDU mounting positions (count, inside/outside, 0U slots) and whether mounting is toolless.
- Raise an error when a design specifies more PDUs per cabinet than the supported positions, and carry PDU brackets as BOM line items.
- Prefer combination outlets in outlet planning when the future IT refresh mix is unknown.
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Who should read it
Designers choosing cabinets and rack PDUs with refresh cycles in mind.
Related standards
- IEC 60320
Publication details
- Authors
- Legrand
- Publisher
- Legrand
- Year
- 2025
- Document language
- English
- Source type
- Manufacturer
- Access
- Free to read
- Licence
- Copyright retained; citation only — the publisher’s terms apply to the original document
Citation
Legrand (2025). Meeting the Demands of Flexible Data Center Design. Legrand. https://legrand.com/datacenter/sites/g/files/ocwmcr716/files/2025-05/White%20Papers%20-%20Meeting%20the%20Demands%20of%20Flexible%20Data%20Center%20Design.pdf
Events on this subject
- Electricity Eurasia 2027
- ELECO 2026 Elektrik-Elektronik ve Biyomedikal Mühendisliği Konferansı
- NVIDIA GTC
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