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The Numbers Behind a GB300-Class Data Center, With Sources

Writers and engineers keep needing the same numbers — and the vendor sources are gated. This page collects the working figures of our published reference design, each with its maturity label, a one-line explanation and a deep-linkable source. Cite them freely with attribution.

K&K drawing E-110: four-path power one-line from a shared utility point of interconnection through transformers, ATS and UPS to PDU paths
K&K program drawing E-110: four-path power to aggregate loads (study revision — not released for construction).

Power

136 kW per rack, A/B dual feed

IT design basis of the electrical reference design: 136 kW per rack with 50/50 normal sharing across dual inputs. [design basis] Source · #

952 kW normal / 1428 kW single-path outage

Per-path IT duty on a six-path, 42-rack zone: what one power path carries normally, and what it must carry when its partner path is out. [design basis] Source · #

2 MW UPS design duty per path

Each radial path carries one UPS block at 2 MW design duty; a 2 x 1200 kVA/kW frame is the stated candidate. Independent UPS outputs are kept un-paralleled. [design basis] Source · #

A 42-rack GPU zone is roughly a 5.7 MW electrical block

42 racks x 136 kW: one hall zone of a GB300-class facility is the size of a whole traditional data center. [arithmetic on the design basis] Source · #

2500 kVA, 12.47 kV to 480Y/277 V, one transformer per path

Critical-power transformer calculation basis on every radial path; each secondary feeds exactly one LV breaker, one ATS and one UPS. [design basis] Source · #

16 x 1 MW generator plant in 4 sections with 3 sync-check couplers

Generator plant study basis serving 13 UPS feeders; first machine closes to a verified dead bus, everything after needs a synchronism-check permissive. [study basis] Source · #

Half a point of UPS efficiency moves 65 kW against an 85 kW utility margin

Why partial-load UPS efficiency is a procurement number, not a datasheet footnote: at this design's scale, 0.5% of efficiency is 65 kW of continuous load against a thin utility margin. [arithmetic on the design basis] Source · #

Strict 2N still misses 0.711 MW in the maintenance-plus-fault case

Redundancy labels are not coverage proofs: the stacked maintenance-plus-fault case leaves a 0.711 MW gap on 12.711 MW even under strict 2N, which is why the design enumerates events instead of trusting the label. [modeled] Source · #

Cooling

A water-rated 1.5 MW CDU delivers about 1.20–1.28 MW on PG25

Nameplate CDU ratings are stated on water; on 25% propylene glycol the modeled delivered capacity drops 15–20%. [modeled] Source · #

155 kW sustained per rack, 95% heat rejection to liquid

Sizing basis of the liquid-cooling set (V8.5): 883.50 kW per 6-rack unit, 2,650.50 kW per 18-rack group, 13.2525 MW liquid load across 90 racks. A deliberately heavier basis than the electrical set's 136 kW IT figure — each discipline states its own. [design assumption] Source · #

A 90-second source transfer at 330 m³/h needs 8.25 m³ of deliverable cold liquid

Why buffer tanks are sized the way they are: the stated transfer-event requirement works out to 8.25 m³ of cold volume; a 15 m³ nominal buffer per ring carries it with stratification margin. [design requirement] Source · #

37/40 °C normal supply; 41/44 °C high-temperature mode; 45 °C hard limit

Primary/secondary coolant temperature ladder of the liquid-cooling reference design; wet cooling is an intended operating mode above 35 °C outdoor dry bulb, not an emergency mode. [design requirement] Source · #

PG25 vs water at 40 °C: flow ×1.045, pressure drop ×1.264, pump power ×1.321, heat transfer ×0.69

The four property ratios of 25% propylene glycol against treated water on generic correlations — the familiar 4.5% flow figure is the smallest of the four effects. [modeled] Source · #

Structure

~1.4 tonnes per liquid-cooled rack

The floor-loading reality of GB300-class racks in continuous rows — the structural set's 170 pages exist because of this number. [design basis] Source · #

Site and civil

60 inches of conduit cover; ~1788 mm excavation

Adopted medium-voltage buried-crossing basis under the shared heavy-vehicle road: 114.3 mm conduit OD plus 150 mm bed gives roughly 1788 mm of excavation — deep enough that worker entry needs an OSHA 1926.652 protective system. [design basis] Source · #

8 branch poles, 13 protected branches, 39 single-pole cutouts, 161 m of underground drops

The route-quantity arithmetic of distributing 12.47 kV to two GPU zones, stated at take-off depth on the site routing sheet. [design basis] Source · #

Water

No evaporative water consumption in normal operation, by design

Dry coolers carry normal duty and the PG25 loop is closed; evaporative wet-assist exists only as a bounded exception mode for sustained heat or dry-cooler outage. [design basis] Source · #

First fill ≈30 t premixed coolant (≈7,700 US gal), one-time, supplier-delivered

A one-time system inventory with a ±30% engineering range — not municipal water and not a recurring draw. [design basis] Source · #

Ten-year emergency-water planning allowance ≈150 t ≈ 39,600 US gallons

One hundred hours at the 1.5 t/h make-up allowance — about 11.4 minutes of the reported 5-million-gallon-per-day ceiling for a large facility; a site whose counted spray hours exceed the budget scales it in proportion. [planning allowance] Source · #

Scale of the published record

371 pages of drawings + 104 analysis articles, free

Electrical 88, structural 170, network 75 (Public Edition P2), liquid cooling 38 pages — plus 106 Lab articles. Every file carries a published SHA-256; every Lab number carries a maturity label. [record] Source · #

How to cite these numbers

Every figure on this page is published in the K&K reference drawing set or the Data Center Lab, with its maturity stated in the bracket: a design basis is what the drawings are engineered around, a modeled figure is calculated analysis, a requirement is a stated performance target — none of them are field measurements. Cite freely with attribution: link either this page (each number has a # anchor) or the linked source. These are reference-design figures for study and evaluation; verify against your own equipment data before use.

Reusing the drawings and figures

The drawing images published on this site (one-line diagrams, equipment plans, sheet renders) may be reused in articles, presentations and teaching material with visible attribution to K&K Data Service Inc. and a link to kkdatasvc.com. The PDF sets carry their own attribution terms inside each document. For other uses, write to inquiry@kkdatasvc.com.

Download the Drawing Set

Every document is a direct PDF download — no registration, no email gate — with a published SHA-256 checksum on the downloads page:

Published at Design Development — Public Edition P1 status: reference designs for study and evaluation, not construction issues, not sealed by an Engineer of Record. Reuse follows the attribution terms stated inside each document.

Common Questions

How much power does a GB300-class rack actually draw?

Published rack-scale figures are on the order of 135–150 kW, fully liquid cooled. The reference design on this site carries a 136 kW-per-rack electrical IT basis and a deliberately heavier 155 kW sustained basis in its liquid-cooling sizing — both stated with their assumptions.

Are these numbers measured from a real facility?

No, and the page says so on every figure: they are design bases, modeled analysis and stated requirements from a published reference design (Design Development — Public Edition), not field measurements. That honesty is the point — each figure links its source so you can judge it.

Can I use these numbers in my own article or deck?

Yes — cite the page or the linked source with attribution. Each figure has a # anchor for deep linking. Drawing images may be embedded with visible attribution and a link.

Questions about any sheet or parameter: inquiry@kkdatasvc.com or the contact page.