Datacenter
Field guide to energizing a new data hall beside live operations
Release temporary and final power states with live-hall dependency evidence, witnessed tests and bounded operating acceptance.
Direct answer
Energize a new hyperscale data hall beside live operations by releasing each temporary and final configuration against its own power, cooling, isolation and test evidence. Keep the one-line state matrix, shared-system dependency register and phase witness plan aligned with the configuration on the floor. Uptime Institute's phased-construction guidance calls for a design that permits commissioning at every phase; Anvilfield's release method separates permission to energize equipment, permission to test under load and permission to admit production IT.
On this page
How do you energize a new hall beside live operations?What belongs in the temporary-to-final one-line state matrix?Which live-hall dependencies belong in the register?Which shared utility release gates must close?Where must isolation boundaries be proved?How does UPS topology change the permitted test state?What is the phased energization test scope?Who witnesses and releases each phase?How do load-bank heat and live cooling capacity set the test ceiling?What stops the test, and how is the plant restored?Worked phasing decision: prove 460 kW before the live load arrivesHow much time and cost belong in the phasing allowance?What evidence permits staged turnover?Open the related tool for the calculation, checklist, or packet.
FieldOS by AnvilfieldOffline-first FieldOS for job photos, proof packets, property memory, calculations, teams, billing, and owner-ready reports.How do you energize a new hall beside live operations?
Start with the load already in production, the load being added and the plant carrying both during each transition. Shared distribution extends the affected system beyond the construction wall. [Uptime Institute's December 2015 phased-construction guidance](https://journal.uptimeinstitute.com/modular-and-phased-construction/) makes that distinction central to planning later demonstrations.
Anvilfield's five release records are: the one-line state matrix, dependency register, phase witness plan, isolation-boundary record and staged turnover register. Keep the same state ID on each record so a passed test cannot drift away from its approved configuration.
Use the [construction and buildout phases guide](https://anvilfield.com/field-guides/datacenter/data-center-construction-buildout-phases/) for the wider delivery sequence. Here, the unit of progress is an accepted operating state: a powered bus with unfinished cooling evidence remains an energized construction system.
What belongs in the temporary-to-final one-line state matrix?
Give each configuration a state ID, drawing revision, mechanical schematic and controls revision, including recovery. The [electrical one-line guide](https://anvilfield.com/field-guides/electrical/electrical-one-line-diagram-reading-symbols/) explains the symbols; this matrix records which combination is authorized.
Table 1 is Anvilfield's planning specimen. H1 is the live hall, H2 the expansion, F2 its feeder, T2 its tie and LB2 its load-bank connection. These hall labels are separate from ASHRAE equipment classes. Attach a device ledger with OPEN, CLOSED, disconnected or the actual OEM mode, source IDs, setting-file revisions and the field verifier.
| State / drawing reference | Authorized sources and load | Shared-system condition | Boundary and settings record | Entry evidence / subsequent release |
|---|---|---|---|---|
| P0 / E-001-R0, live baseline | H1 on existing approved supply; H2 test and IT load 0 kW | Existing power and cooling retained | F2 OPEN and work isolation verified; T2 OPEN; LB2 disconnected; H1 settings R0 | Entry: verified live baseline and isolations; exit: approved P1 release |
| P1 / E-001-R1, new feeder energization | H1 retained; H2 auxiliary/startup loads only as released; H2 IT load 0 kW | Cooling/control dependencies available for startup | F2 CLOSED after boundary release; T2 OPEN; LB2 disconnected; settings R1 | Entry: equipment acceptance, isolation clearance and utility event authority where required; exit: accepted startup records |
| P2 / E-001-R2, test configuration | H1 retained; H2 bank load only to signed test ceiling; H2 IT load 0 kW | Live plus bank heat within retained plant's approved capacity | F2 CLOSED; T2 OPEN; LB2 connected in approved test arrangement; source IDs, OEM mode and settings file R2 recorded | Entry: approved test script and live-support proof; exit: witnessed results and cleared release blockers |
| R2 / E-001-R2R, approved recovery | H1 on specifically identified retained supply; H2 bank load removed through approved response | Required H1 cooling and controls confirmed | Recovery positions/settings match R2R; no automatic assumption P0 remains reachable | Entry: approved recovery response; exit: verified restored state and operations reauthorization |
| P3 / E-001-R3, staged operations | H1 retained; H2 IT load within released phase ceiling; temporary bank load 0 kW | Released phase redundancy and cooling proven | Temporary connections retired or explicitly retained; final settings R3 | Entry: staged turnover acceptance and bounded operating instructions |
| P4 / E-001-R4, final service | Both halls within final approved ceilings and load ramp | Final common systems demonstrated | Final one-line, mechanical schematic, software and settings aligned | Entry: final affected-system acceptance; exit: contractual closeout |
Record the source, load ceiling and return state
Temporary utility service, a bridging arrangement, temporary generation and an internal temporary feeder are different supplies. [Dominion Energy Virginia](https://www.dominionenergy.com/virginia/large-business-services/data-center-requests) describes bridging service for initial loading while the final power plan is built.
For each state, record live IT, new IT, bank and auxiliary loads at their electrical supply boundaries, and heat at each cooling boundary. Verify kW, kVA, current, power factor and transient constraints separately; do not take a minimum across unlike units. Meet every service, equipment, protection and surviving-support limit.
Include transformer inrush, UPS recharge and cooling restart in the approved transient review. Link the topology to its [protection study and as-left settings](https://anvilfield.com/field-guides/datacenter/protective-relay-coordination-study/). Restoration needs its own reachable, verified state; reversing the forward steps does not prove that state exists.
Which live-hall dependencies belong in the register?
A live-hall dependency register must follow shared power, cooling, controls, fuel and protection across the construction boundary, because the equipment being added is only part of the system exposed by a phase test. Trace each isolation or failure to the live consumer. CxA means commissioning authority in the tables.
| ID / shared asset | Live dependency and credible change | Evidence owner / record | Hold condition | Release and revalidation |
|---|---|---|---|---|
| D01 / MV bus and protective relay | H1 supply affected by H2 fault contribution or changed settings | Electrical engineer / approved study plus as-left relay export | Changed topology not covered by study or settings mismatch | Engineer confirms design; operations authorizes state; recheck after source/settings change |
| D02 / generator and fuel system | H1 support competes with bank load; common fuel pump unavailable | Electrical/mechanical leads / load ledger, fuel and sequence test | Required retained capacity or fuel delivery unavailable | Operations/CxA under contract; recheck after added load or pump isolation |
| D03 / chilled-water header | New branch tie-in affects H1 flow, pressure or water quality | Mechanical lead / isolation drawing and retained-flow evidence | Retained cooling cannot meet approved live demand | Operations release; recheck after valve, pump or water-system change |
| D04 / controls and control power | Shared PLC restart or loss of its supply affects both halls | Controls lead / cause-and-effect and power-path record | Common failure response or restart unproved | Operations/CxA; recheck after logic, firmware or control-supply change |
| D05 / UPS bypass and battery | Live critical load loses intended ride-through in a test state | OEM/electrical lead / model-specific one-line and test-state record | Actual bypass state differs from permitted exposure | Operations; recheck after mode, module or battery-path change |
| D06 / fire, EPO and suppression interfaces | Expansion test trips or impairs live protection | Fire-system lead / approved cause-and-effect and impairment record | Required protection unavailable or live trip exposure uncontrolled | Authorized impairment authority and operations; recheck after cause-and-effect change |
| D07 / EPMS/BMS network and clocks | Witnesses cannot correlate live and new-hall events | Controls lead / communications and timestamp validation | Required observation or alarm path lost | CxA/operations; recheck after network or logging change |
| D08 / construction airflow and access | Dust, bank exhaust or route obstruction affects live operation | Construction manager / containment, airflow and access walkdown | Live inlet exposure or blocked required access | Operations; recheck after bank relocation or boundary move |
MV means medium voltage; PLC means programmable logic controller; EPMS and BMS are electrical power and building management systems. EPO identifies emergency power off.
Review overlapping maintenance, utility work, generator availability and controls releases against these same dependencies. One operations authority resolves competing windows: two teams cannot each reserve the same remaining path. Apply [concurrent maintainability](https://anvilfield.com/field-guides/glossary/concurrent-maintainability/) to the actual maintenance state and live load, with retained capacity demonstrated for that combination.
Add human dependencies alongside the equipment rows: the authorized operator, required OEM support, witness and recovery crew.
Which shared utility release gates must close?
Close the utility service gate and the owner's operating gates separately. Table 3 uses Anvilfield gate labels: U releases the utility boundary, E the equipment, T the test and O production. A will-serve letter or future capacity plan does not authorize today's switching event or bank load.
| Gate | Concrete required evidence | Decision owner | Authorizes | Does not establish |
|---|---|---|---|---|
| U / service increment | Accepted load ramp, service/inspection/metering and commercial requirements, utility event authorization | Serving utility for its boundary | Specified connection and permitted service conditions | H2 commissioning completion or future campus capacity |
| E / equipment energization | Acceptance records, installed protection settings, exact energization boundary and released work permits | Owner's designated electrical release authority | Energizing the defined equipment | Permission for unrestricted bank or IT load |
| T / test load | Approved script, live dependency review, witness attendance, heat/load ledger, restoration plan | Operations change authority with CxA technical acceptance per contract | Specified test in specified window/state | Release of untested states or production occupancy |
| O / production phase | Passed required tests, as-left records, procedures/training, closed release blockers | Owner's operating acceptance authority | Bounded phase IT loading | Final campus acceptance or independent certification |
[Dominion Energy's May 2026 large-load report, pages 4-5](https://sustainability.dominionenergy.com/GS-5%20Large%20Load%20Rate%20Class%20Report.pdf) requests a site/building layout, construction schedule, load ramp, building loads where applicable and meter delivery method. Include the added hall and simultaneous test peak in that load description. The serving utility's agreement and event authorization define the actual service boundary.
Match bridging service to the load ramp
Carry the temporary service identifier, permitted increment and conditions into the state matrix. Request the next increment before loading changes, including the live halls, banks and auxiliaries that run together. Bridging-service acceptance does not establish the final source's protection, transfer performance or full campus capacity.
Dominion's process is a Virginia utility example; apply the actual serving utility's documents to the project. Use the [utility energization document register](https://anvilfield.com/field-guides/datacenter/utility-energization-document-register/) to track inspection, metering, agreement and switching records.
Where must isolation boundaries be proved?
Prove both the separation protecting production and the hazardous-energy isolation protecting exposed work. An open symbol on the one-line proves neither in the field. Identify every source, including generation, ties, UPS bypass, batteries, parallel modules and possible backfeed, before releasing the work boundary.
For general-industry work at 50 V or more to ground, 29 CFR 1910.333(a)(1), 2025 edition, requires exposed live parts to be deenergized before work on or near them unless the employer demonstrates increased hazards or infeasibility from equipment design or operational limitations. A production schedule alone does not establish that exception. [Federal electrical work practices](https://www.govinfo.gov/content/pkg/CFR-2025-title29-vol5/pdf/CFR-2025-title29-vol5-sec1910-333.pdf).
The same regulation's paragraph (b)(2) requires all-source disconnection, control of hazardous stored energy, lockout/tagging and qualified-person verification before exposed parts are treated as deenergized. Control switches and interlocks alone cannot provide isolation. Paragraph (iii) generally requires a lock and tag at each disconnecting means; its tag-only exception requires equivalent protection and an additional safety measure.
Under 29 CFR 1910.333(b)(2)(iv), 2025 edition, a qualified person verifies restart prevention and tests exposed circuit parts for voltage, including induced voltage and unrelated backfeed. For circuits over 600 V nominal, the instrument must be checked immediately before and after that test; voltage verification also applies below that threshold.
| Boundary | Paths to identify | Evidence before exposure or test | Consequence of missing proof | Authority |
|---|---|---|---|---|
| New feeder work zone | Utility, generation, cross-ties, induced voltage and backfeed | Applicable locks/tags, stored-energy controls, restart prevention and qualified-person voltage verification | Treat as energized; do not release exposed work as deenergized | 29 CFR 1910.333(b)(1)-(2), 2025 edition |
| UPS work zone | Rectifier, bypass, output, batteries/DC, parallel modules | Installed OEM topology plus AC/DC isolation and voltage verification | Input-off indication does not release cabinet work | 29 CFR 1910.333 (2025); Vertiv EXL S1 rev. 11 p. 1 and one-lines |
| Construction circuit | Every point capable of energizing the deenergized circuit | Circuit rendered inoperative; identifying tags at applicable energization points | Construction circuit not released under the stated control | 1926.417, 2025 CFR |
| Chilled-water branch | Supply, return, bypass, interconnected pumps and stored pressure | Approved isolation, pressure/energy verification and retained live-flow record | Hold tie-in or test that removes required live cooling | Anvilfield boundary method; 1910.147 for covered servicing |
| Controls/fire interface | Common control power, EPO, alarms and inhibited outputs | Approved cause-and-effect test boundary and restored inhibitions | Hold test if live effect or required protection is unaccounted for | Anvilfield boundary method |
Construction work has its own scope. Under 29 CFR 1926.416(a)(1), 2025 edition, protect workers who could contact a power circuit by deenergizing and grounding it or guarding it effectively with insulation or other means. [Construction electrical protection](https://www.govinfo.gov/content/pkg/CFR-2025-title29-vol8/pdf/CFR-2025-title29-vol8-sec1926-416.pdf).
29 CFR 1926.417, 2025 edition, requires deenergized circuits to be rendered inoperative and tagged at all points capable of energizing them. [Construction circuit controls](https://www.govinfo.gov/content/pkg/CFR-2025-title29-vol8/pdf/CFR-2025-title29-vol8-sec1926-417.pdf).
Before even temporary reenergization, 29 CFR 1910.333(b)(2)(v), 2025 edition, requires checks that temporary devices and tools are removed, warnings to exposed employees, prescribed lock/tag removal and verification that employees are clear. Keep these checks in the switching procedure and entry evidence for the energized state.
Close the non-electrical routes across the boundary
Verify chilled-water isolation, stored pressure and retained live flow under the site's energy-control procedure. For covered general-industry servicing, 29 CFR 1910.147(d)(5)-(6), 2025 edition, requires stored-energy control and isolation verification; its scope excludes construction employment. [Hazardous-energy control](https://www.govinfo.gov/content/pkg/CFR-2025-title29-vol5/pdf/CFR-2025-title29-vol5-sec1910-147.pdf). Record shared fire/EPO interfaces, temporary exhaust and communications; a time-limited controls inhibit needs authorization and restoration proof, and provides no hazardous-energy isolation.
How does UPS topology change the permitted test state?
Select the installed model, options and test arrangement before assigning the critical-load source. Table 5 compares the [Vertiv EXL S1 manual](https://www.vertiv.cn/49c3b3/globalassets/products/critical-power/uninterruptible-power-supplies-ups/liebert-exl-s1-ups-operation--maintenance-manual---single--multi-module_00.pdf), sections 3.6-3.7, and the [Eaton 93PM manual](https://www.eaton.com/content/dam/eaton/products/backup-power-ups-surge-it-power-distribution/backup-power-ups/eaton-93pm-ups/manuals/eaton-93pm-400-ups-P-164000483.pdf), section 5.2.4.
| Source / exact application | Verified distinction or value | Phase-planning consequence |
|---|---|---|
| Vertiv EXL S1, 250-1200 kVA, 60 Hz; SL-26090 rev. 11, May 2026, §3.6 | Equipped system load-bank arrangement uses maintenance bypass to support the critical bus | Record critical-load exposure and bypass source; prove return to inverter |
| Vertiv EXL S1, SL-26090 rev. 11, May 2026, §3.7 | Equipped isolated-module arrangement leaves the critical bus on inverter, subject to sufficient remaining UPS modules | Prove remaining capacity and module isolation; do not classify this as the system test above |
| Vertiv EXL S1, SL-26090 rev. 11, May 2026, p. 1 | Expected capacitor discharge within 5 minutes after specified disconnections; voltage can remain after failure | Elapsed time does not replace AC/DC voltage verification |
| Eaton 93PM, 480 V three-wire, 400 kW frame; P-164000483 rev. 13 | Bypass mode supplies load without active power conditioning or battery support | Do not equate a healthy bypass-fed bus with protected inverter operation; apply Eaton's installed configuration and procedure |
Treat bypass and return-to-normal as evidence states
Record the critical-load source, battery path, remaining module membership, bypass availability and alarm status before loading and after reintegration. Use the [UPS and STS commissioning hold points](https://anvilfield.com/field-guides/datacenter/ups-sts-commissioning-hold-points/) for transfer evidence. Breaker abbreviations, commands and source arrangements belong to the installed OEM procedure; copying them from another model changes the meaning.
Capacitor discharge time is not a release criterion for contact. Retain AC and DC voltage verification for the complete work boundary, including external sources still connected to bypass or output terminals.
What is the phased energization test scope?
Test the new equipment, its functional sequences and every changed interface with the retained plant. [ANSI/NETA ATS-2025](https://www.netaworld.org/standards/ansi-neta-ats) addresses acceptance testing for initial energization; [ANSI/NETA ECS-2024](https://www.netaworld.org/standards/ansi-neta-ecs) addresses electrical system performance against the owner's project requirements and basis of design. Enter equipment-specific pass values from the contracted test specification and installed OEM instructions.
| Changed item / phase condition | Evidence retained from an earlier phase | New or repeated scope | Release proof |
|---|---|---|---|
| H2 feeder added to shared MV bus | Unchanged H1 equipment reports after applicability review | H2 acceptance and functional tests; verify changed fault-duty, coordination and relay settings; affected shared response | Approved study, as-left settings and witnessed applicable response |
| Temporary source replaced by permanent utility supply | Unchanged downstream installation tests whose conditions remain applicable | Source/phasing/protection verification and affected transfer, interlock, metering and recovery tests | Final-source state ID and its accepted results |
| UPS module added to a parallel group | Accepted unchanged module-specific evidence | New module acceptance and OEM integration; affected capacity-sharing, transfer, alarms and reintegration proof | Installed module membership, retained capacity and normal-mode return |
| Shared cooling branch or pump added | Unchanged equipment tests with matching duty | New branch cleaning/pressure/flow evidence under project criteria; changed sequence, isolation, restart and thermal duty | Retained live flow and accepted phase heat-removal results |
| PLC logic or control wiring corrected after failed test | Applicable unaffected equipment acceptance | Repeat the full affected procedure and its dependent scenarios, including restoration | Versioned logic, closed defect, repeated results and live-interface observations |
| Required seasonal duty unavailable | Tests completed at recorded ambient conditions | Scheduled seasonal verification and any accepted interim analysis under project requirements | Named deferred test and bounded interim load/mode release |
Enter pass values, units and revisions in scripts covering required normal, maintenance, failure and recovery responses at the specified load and conditions. The [electrical commissioning and power QA guide](https://anvilfield.com/field-guides/datacenter/datacenter-electrical-commissioning-power-qa/) covers equipment acceptance; the [integrated systems test guide](https://anvilfield.com/field-guides/datacenter/integrated-systems-test-ist-commissioning/) develops the combined scenarios.
Decide what earlier evidence still covers
Carry forward evidence only after matching equipment, topology, software, settings, load conditions and acceptance requirements. Uptime's December 2015 guidance warns that capacity additions on shared distribution can require demonstrations across the whole shared system.
When a required failure demonstration would expose live IT to an unaccepted state, bring it forward before production, use a separately approved arrangement proving the same requirement, or defer the affected operating release. A desktop review or stable live bus does not replace required physical performance evidence. Record which requirement an alternative arrangement proves and who accepts that equivalence.
After programming or control-wiring corrections to a failed step, [Uptime's May 2015 commissioning guidance](https://journal.uptimeinstitute.com/improve-project-success-through-mission-critical-commissioning/) calls for repeating the entire affected procedure. Identify dependent scenarios too, including restoration. Keep equipment acceptance, functional tests, integrated commissioning and Tier demonstrations separate: the owner and commissioning authority (CxA) accept contractual evidence, while Uptime determines its own certification demonstration requirements.
Who witnesses and releases each phase?
Name the performer, technical witness, live-operations observer and next-state release authority. Replace the specimen roles in Table 7 with authorized project participants.
| Phase/test event | Performer | Technical witness / live observer | Pass evidence and hold point | Next-state release |
|---|---|---|---|---|
| Deenergized new-equipment acceptance | Qualified testing organization | CxA per plan; electrical lead | Equipment-specific approved test results; defects affecting energization closed | Owner electrical authority releases P1 |
| New feeder/UPS startup | Authorized operator and OEM as required | CxA/electrical lead; live operations | Correct source, settings, alarms and state; no unexpected live-hall effect | Operations permits functional test state |
| Isolated-module test | OEM/authorized test team | CxA; live operations on retained modules | Remaining capacity and isolation proved; approved loading/results recorded | Operations permits return/reintegration |
| Shared-system integrated event | Authorized operators and controls/test teams | CxA; live operations with stop authority; certification witness if separately required | Expected response, timestamps, retained live capacity and recovery all meet approved script | Owner accepts tested phase after closure |
| Return to normal | Authorized operations team | Independent verification as project requires | Correct modes, module membership, alarms and restored redundancy recorded | Operations closes work window |
| Staged production handoff | Contractor/CxA compile records | Owner operations reviews | Table 10 release package complete | Owner authorizes bounded IT ramp |
Attach the source state, expected end state, test load, acceptance-document revision and exact pass values to every test ID. Record measurement location, calibrated instrument, timestamps, raw trends and the related defect record.
Specify the sampling or event-capture interval against each timing criterion. Event capture must resolve the shortest acceptance interval: a slow BMS trend cannot prove a millisecond transfer. Use the [EPMS and power-monitoring guide](https://anvilfield.com/field-guides/datacenter/epms-power-monitoring-metering/) to plan electrical event evidence alongside thermal and controls data.
Set witness notices and mandatory hold points before mobilization. If a required witness is absent, hold or use the plan's formally authorized alternative.
How do load-bank heat and live cooling capacity set the test ceiling?
Add live IT heat, bank heat and other heat rejected inside the same cooling boundary. Count electrical losses where they physically become heat; a loss outside the hall belongs elsewhere in the ledger. An outdoor bank can prove electrical loading without demonstrating the hall's airflow or CDU performance.
ASHRAE's 2023 HVAC Applications Handbook, chapter 20, reproducing its 2021 fifth-edition guidance, recommends inlet dry-bulb temperatures of 18 to 27°C for A1-A4 equipment and 18 to 22°C for H1 equipment. These inlet recommendations are not automatic trip thresholds. [ASHRAE thermal guidance](https://handbook.ashrae.org/Handbooks/A23/SI/A23_Ch20/a23_ch20_si.aspx).
For non-tape ITE, the same ASHRAE guidance limits maximum-minus-minimum inlet temperature to 5°C in any 15-minute window and 20°C in any one-hour window; tape storage has a 5°C limit within an hour. These are rolling-window changes, not instantaneous ramp rates. Apply the installed ITE manufacturer's envelope and approved project stop criteria alongside the applicable class.
Log outdoor dry-bulb/wet-bulb conditions and retained-plant capacity using OEM chiller, economizer, generator and bank deratings. Carry an uncompleted hot-weather duty as a dated deferred test with an interim operating ceiling; cool-weather success does not close that obligation.
Liquid-cooled racks also need coolant temperature, flow, water quality, dew point and residual air-load criteria. Air-cooled class ranges do not establish CDU coolant limits. Pair the [ITE thermal-envelope guide](https://anvilfield.com/field-guides/datacenter/data-center-thermal-envelope-ashrae-setpoints/) with [CDU commissioning evidence](https://anvilfield.com/field-guides/datacenter/cdu-coolant-distribution-unit-commissioning/) to keep both heat paths visible.
Distribute banks to reproduce the intended rack airflow or liquid heat path, and measure equipment inlets in both halls. ASHRAE's 2023 chapter 20 also warns that plant sized for ultimate load can perform poorly at initial low load. Include the first production stage in the sequence review so minimum flow, plant staging and redundant operation remain compatible.
Advance through the script's load plateaus only after readings stabilize within its criteria. Reconcile actual live heat before each increment; a changing production load changes the bank allowance.
What stops the test, and how is the plant restored?
Stop progression for an unexpected live-hall alarm, unexplained electrical or thermal trend, lost retained path, mismatched device position, failed test communications or insufficient time to restore. Define the approved response to each trigger before the test. Stopping means executing that response, not abruptly removing cooling or opening an arbitrary source.
The [approved MOP and recovery procedure](https://anvilfield.com/field-guides/datacenter/data-center-mop-sop-eop-procedures/) carries the actual actions. Write numeric trigger values and measurement locations into the script from the project's accepted limits. Give the live-operations representative clear stop authority and a communication route that remains available during the event.
Distinguish a plant excursion from a telemetry fault with time-aligned independent measurements and device logs. A temperature alarm with matching inlet measurements requires a plant response; a lone sensor discrepancy still holds the affected test until resolved. Dashboard recovery alone does not explain the event or establish acceptance.
Before closing the change, reconcile the as-found and as-left matrix rows, settings, active alarms, test connections and outstanding isolations. Treat an unplanned configuration as a new state requiring review.
Worked phasing decision: prove 460 kW before the live load arrives
Uptime Institute's December 2015 single-hall South African case reports 154 kW of initial IT capacity, a 306 kW second-phase addition and 460 kW final capacity. During phase 1, the team demonstrated the AHUs at the final heat load, with both chillers and engine-generators operating at N capacity. [Published phased-construction case](https://journal.uptimeinstitute.com/modular-and-phased-construction/).
| Input or result | Value | Provenance and use |
|---|---|---|
| Initial IT phase | 154 kW | Uptime December 2015 South African case |
| Added second phase | 306 kW | Uptime December 2015 case |
| Final planned IT load | 460 kW | Uptime December 2015 case; 154 + 306 |
| Extra bank heat to reach 460 kW with 154 kW of actual live IT heat in the same boundary | 306 kW | Anvilfield estimates: target minus live heat; support losses are accounted separately |
| Additional bank heat when the same boundary also rejects a stated 20 kW of support heat | 286 kW | Anvilfield estimates: 460 - 154 - 20; count that support heat once |
| Heat if a full 460 kW bank is added beside that 154 kW live heat | 614 kW | Anvilfield estimates: 460 + 154; exceeds the 460 kW demonstration point by 154 kW |
N denotes the capacity needed to carry the load. The second phase still required demonstrations of the overall chilled-water piping and additional electrical systems.
Method: Anvilfield estimates later bank heat by subtracting actual live heat and other heat within the boundary from the target: bank kW = target kW - live kW - support kW. The later-test inputs are 154 kW live heat and, in the support-heat row, 20 kW additional heat; Uptime supplies the published phase capacities. Record electrical loading separately at each supply boundary, including auxiliaries and losses outside the hall.
How much time and cost belong in the phasing allowance?
Uptime Institute's May 2015 Level 4 guidance recommends at least 8 continuous hours for load-bank tests and describes runs up to 24 hours as best practice. Its Level 5 planning discussion spans a few days for small/basic sites to 20 working days or longer for complex scope. The approved equipment, project and utility requirements set the actual duty. [Uptime commissioning guidance](https://journal.uptimeinstitute.com/improve-project-success-through-mission-critical-commissioning/).
| Item | Filled value | Basis and action |
|---|---|---|
| Approved change window in Anvilfield calculation | 6 hours | Planning input |
| Precondition checks | 1 hour | Planning input |
| Reserved restoration | 1 hour | Planning input; use actual approved recovery duration on the job |
| Post-restoration verification | 1 hour | Planning input |
| Forward-work allowance for bounded connection/transition task | 3 hours | Anvilfield estimates: 6 - 1 - 1 - 1; continuous bank run is scheduled separately |
| Latest scheduled end of forward work | Hour 4 from window start | 1-hour prechecks plus 3-hour forward allowance; stop earlier when a trigger requires |
| Window for 8-hour continuous runtime with the same allowances | 11 hours minimum | Anvilfield estimates: 8 + 1 + 1 + 1; extra setup/stabilization extends this if required |
| Dominion Engineering Letter of Agreement (ELOA) payment | $250,000 at signing | Dominion May 2026 report; additional engineering costs require additional payment |
| Dominion Construction Letter of Agreement (CLOA) signing period | 90 days from issuance | Dominion May 2026 report; separate commercial decision, not permission to run tests |
| Test-support contract price | Quantity-priced scope, no universal $/MW rate | Count visits, connections, rental days, attendance, energy and retests |
Schedule continuous bank duty in a separately released state or obtain a window that contains the full duty and recovery allowances.
Method: subtract reserved prechecks, restoration and verification from the approved window before allocating forward work. Add those allowances to continuous runtime when one window must contain both. Replace these planning inputs with timed procedure durations and add setup or stabilization where required; never consume the recovery reserve to finish another test step.
Table 9's Virginia utility terms come from [Dominion's May 2026 report, page 4](https://sustainability.dominionenergy.com/GS-5%20Large%20Load%20Rate%20Class%20Report.pdf); the executed agreement governs. Budget utility commitments separately from test support.
Carry each revisit as an identifiable scope item
Price phase mobilizations, connection moves, rental days, logging, OEM and witness attendance, energy, retests and restoration as owned quantities. Distinguish planned deferred testing from failure retests and idle time awaiting release. Use the [subcontract scope and retest guide](https://anvilfield.com/field-guides/datacenter/data-center-commissioning-subcontract-scope-retests/) for dollar build-ups and the [commissioning duration benchmark](https://anvilfield.com/field-guides/datacenter/data-center-commissioning-duration-benchmark/) for program comparisons.
Public electrical procurement packages should identify phase mobilizations, temporary connections, witness attendance and restoration as separate scope quantities. Estimators pricing staged electrical packages can find previous public bid winners and award amounts through [PorchRocket Bid Control](/bidcontrol/electrical) when planning their next bid.
What evidence permits staged turnover?
Anvilfield's staged-turnover rule is zero open release blockers: an unresolved isolation, protection, life-safety, load-support or required test failure blocks the affected operating release. Give operations the accepted state, permitted IT ceiling, operating modes and future work excluded from the release.
| Release | Required retained evidence | Blocking condition | Operating scope after acceptance |
|---|---|---|---|
| Equipment energized | Acceptance results, source permission, settings and boundary release | Unresolved energization/protection/isolation defect | Defined energized equipment and permitted startup work |
| Phase tested | Signed scripts, loads, trends, witness record and return-state evidence | Failed required function or unresolved shared-system effect | Tested state and loading only; production awaits its release |
| Phase in production | Phase matrix, live dependency proof, trained operations, current procedures, closed blockers | Required load-support, life-safety or acceptance evidence missing | Explicit IT ceiling, permitted modes and deferred-scope restrictions |
| Final configuration | Final studies/as-lefts, affected regression results, temporary-work retirement and closeout | Final topology or shared-interface proof incomplete | Final accepted operating envelope |
Carry each deferred obligation with a test ID, affected state, reason, interim load/mode restriction, owner, due date and acceptance authority. Nonblocking closeout items also need owners and dates; an unresolved item affecting required support remains a blocker regardless of its punch-list label.
Review the gate at each transition and after changes to topology, settings, logic, load ceiling or evidence applicability. Supply redlines, as-left settings, permits, event records, witness signatures, defect/retest closure, procedures and training. The [punch-list and turnover guide](https://anvilfield.com/field-guides/datacenter/punch-list-closeout-turnover/) supports that handoff; staged operating acceptance, contractual closeout and certification remain separate decisions.
Write the production ramp as permitted increments with required observations and a named approver for each increase. Verify measured IT demand, retained power and cooling availability, alarm status and unresolved restrictions before adding the next block. Reopen the affected release when those assumptions change.
Field release checklist: yes or hold
Apply each item to the intended transition while existing production remains supported.
- State ID, electrical one-line, mechanical schematic and controls revisions match the field. Mismatch: hold transition.
- Actual live kW and test kW are assigned to their sources and cooling boundaries. Unknown load or heat path: hold loading.
- Utility service identifier, permitted increment and event authorization match this phase. Wrong service or increment: hold the utility-dependent event.
- New equipment acceptance and as-left protection records are accepted for this topology. Missing or mismatched records: hold energization.
- Applicable hazardous-energy isolation and verification are complete for the work exposure. Missing proof: do not release work as deenergized.
- Retained power, cooling, fuel and control paths support the live hall during the planned state. Unavailable required path: hold test.
- Installed UPS arrangement, mode and module count match the selected OEM test method. Mismatch: hold test.
- Bank connection, heat discharge and construction containment are verified. Uncontrolled live-inlet exposure: hold loading.
- Continuous runtime, stabilization and restoration fit their approved windows and duty. Short window: hold or reschedule the affected test.
- Concurrent campus work does not consume the same retained path or crew. Conflict: hold the overlapping change.
- Required witnesses, operators and stop authority are present and acknowledged. Missing mandatory participant: hold under the plan.
- Instruments, event capture, timestamps and alarm routes are ready. Inadequate evidence capture: hold acceptance testing.
- Trigger values, recovery sequence and remaining restoration time are explicit. Unworkable recovery: hold forward work.
- Defects have closure evidence and affected tests have been repeated. Open release blocker: hold that release.
- Temporary inhibits, test connections and abnormal modes are removed or explicitly retained in the accepted state. Unrecorded exception: hold change closure.
- Operations has current procedures, training, load ceiling and deferred obligations. Incomplete handoff: hold production release.
Sources checked and review date: 2026-11-05. Update log: 2026-11-05, final review clarified electrical work controls, state-entry evidence, low-load testing and the production ramp; rechecked source editions, numbers and calculations.
How to cite this page: Anvilfield, Field guide to energizing a new data hall beside live operations, 2026, https://anvilfield.com/field-guides/datacenter/hyperscale-data-center-phased-energization/.
FAQ
How do you phase hyperscale energization beside live halls?
Release each configuration against its source, isolation, retained live-support and witnessed test evidence. Carry the same state ID across the release records. Energization, test loading and production admission each need approval.
What is a temporary-to-final one-line matrix?
It links drawing revisions, device positions, sources, load ceilings and recovery arrangements to required evidence. Give temporary, test, recovery and final configurations separate rows, showing entry evidence and next-state release criteria.
Which shared utility release gates must close?
The utility authorizes its service event; the owner separately releases equipment, testing and production. Include live load, simultaneous banks and auxiliaries in the submitted ramp. Future capacity does not release today's test.
What belongs in phased energization test scope?
Test new equipment, changed interfaces and affected integrated scenarios at the approved load and conditions. Retain earlier reports only where topology, settings, software, duty and criteria still match. Include failure recovery and return to the accepted state.
Does a temporary supply prove permanent-service performance?
Temporary-source evidence covers the tested configuration. A changed final source requires applicable source, protection, transfer, interlock, metering and recovery verification.
Can load-bank testing leave the live critical bus on inverter?
Yes, with the installed arrangement and retained capacity proved. Vertiv EXL S1 revision 11 distinguishes isolated-module and whole-system tests; Table 5 identifies their critical-bus sources. Apply the installed OEM procedure and document reintegration.
How much bank heat belongs beside a 154 kW live load at a 460 kW target?
Anvilfield estimates 306 kW before other heat within the cooling boundary. With the worked example's additional 20 kW support heat, bank heat becomes 286 kW. Use actual live heat, rather than installed phase capacity, in the test ledger.
Is 27°C the inlet limit for every hall?
ASHRAE classes have different recommended inlet ranges, listed in the thermal-test section. Use the installed class and OEM envelope to set project stop values. Room averages do not establish rack inlet conditions.
How long should phased load-bank testing run?
Uptime's May 2015 guidance recommends at least eight continuous hours and describes runs up to 24 hours as best practice. Apply the approved project duty, and reserve separate time for prechecks, setup, stabilization, restoration and verification.
Can one hall enter production before final campus turnover?
Yes, when its bounded operating state meets its release criteria and all dependencies supporting its live load are accepted. Carry deferred tests, interim restrictions and due dates forward; phase acceptance does not establish final campus acceptance or certification.
People also ask
Codes cited in this guide
This guide is written and reviewed against the published standards below. Always confirm the current adopted edition with the authority having jurisdiction.
Sources checked
- Uptime Institute: Tier Certification for Modular and Phased Construction (December 14, 2015) Checked 2026-11-05.
- Uptime Institute: Improve Project Success Through Mission Critical Commissioning (May 4, 2015) Checked 2026-11-05.
- NETA: ANSI/NETA ATS-2025 publisher scope Checked 2026-11-05.
- Dominion Energy Virginia: Data Center Requests Checked 2026-11-05.
- Dominion Energy: Meeting the Demands for Large-Load Customers (May 2026), pages 4-5 Checked 2026-11-05.
- ASHRAE: 2023 HVAC Applications Handbook, chapter 20, including 2021 fifth-edition thermal guidance Checked 2026-11-05.
- Colt DCS: Hyperscale in Action, Implementation and Beyond (2020) Checked 2026-11-05. Implementation and phased-delivery context.
- NETA: ANSI/NETA ECS-2024 publisher scope Checked 2026-11-05.
- GPO: 29 CFR 1910.333, 2025 annual edition Checked 2026-11-05.
- GPO: 29 CFR 1926.417, 2025 annual edition Checked 2026-11-05.
- Vertiv: Liebert EXL S1, SL-26090 revision 11, May 2026, pages 1 and 31-32 Checked 2026-11-05.
- Eaton: 93PM 480 V Three-Wire, 400 kW Frame, P-164000483 revision 13, section 5.2.4 Checked 2026-11-05.
- GPO: 29 CFR 1926.416, 2025 annual edition, Construction electrical protection Checked 2026-11-05.
- GPO: 29 CFR 1910.147, 2025 annual edition, Control of hazardous energy Checked 2026-11-05.