Why is the cockpit locked — no user inputs?

The EPMS/BMS cockpit is a simulated monitoring and anomaly-detection aid, not a design calculator or live field-control system. Its numbers represent a single authenticated engineering scenario (IT load 1,850 kW, PUE 1.45) anchored in conv review doc 09. Allowing arbitrary inputs would break the ACCURACY_VALIDATION 6-rule contract and produce engineering-indefensible output. All KPIs are derived deterministically from CONV_CALC.

What is the canonical chilled-water loop basis?

The primary (secondary) CHW loop runs at 7.2 °C supply / 14.8 °C return (ΔT = 7.6 K). This resolves the 7.2/14.8 vs 19.1/22.6 conflict documented in conv-engine.js: the ~19/23 °C readings are the condenser-side loop and are never labelled CHWS/CHWR in the cockpit. Source: conv review doc 09 lines 15, 81–84.

How is WUE derived and what does 37 L/min mean?

WUE = 1.20 L/kWh is the site water-usage effectiveness target under ISO/IEC 30134-9. The cockpit converts it to an equivalent average flow: 1.20 × 1,850 / 60 = 37.0 L/min. It is not relabeled as a measured instantaneous cooling-tower flow.

Conventional DC — EPMS & BMS Cockpit — Technical Manual & Methodology

01 Purpose & engineering basis

The Conventional DC cockpit is a simulated EPMS/BMS monitoring and anomaly-detection aid for a chilled-water, UPS-backed, generator-protected data centre. It answers five questions within one deterministic scenario: what is the modeled energy balance, is cooling performing within design, how are the UPS modules loaded, how much fuel autonomy remains, and how do site sustainability metrics (PUE/WUE/CUE) compare to design targets. It neither connects to nor controls field equipment.

This page is a cockpit, not a calculator. Its basis of design is fixed: the scenario constants in CONV_MODEL (locked, deep-frozen) drive every displayed number. The governing accuracy contract is the ACCURACY_VALIDATION 6 rules (one source of truth · no Math.random on basis KPIs · explicit denominator on every metric · marketing target ≠ derived value · terminology must match engineering basis · basis chip on every critical KPI), plus the 23 acceptance tests in tools/probe-accuracy-validation.mjs. Basis document: conv/review/09-engineering-basis-and-calculations.md.

02 Inputs — locked basis-of-design

There are no user inputs. The table below is the complete set of authored constants in CONV_MODEL. Every other number on every cockpit page is derived from these. Source citations map to conv review doc 09 line numbers.

Parameter	Symbol / key	Value	Unit	Source
IT design capacity	`it_design_kw`	2 000	kW	doc-09 line 9
IT load (current)	`it_load_kw`	1 850	kW	doc-09 line 10
Power usage effectiveness	`pue`	1.45	—	doc-09 line 11
Water usage effectiveness	`wue_l_per_kwh`	1.20	L/kWh	doc-09 line 13
Grid carbon intensity	`carbon_kg_per_facility_kwh`	0.42	kgCO₂/kWh	doc-09 line 14, denominator = facility kWh
Cold-aisle average temperature	`avg_temp_c`	22.4	°C	doc-01 §Right-Side Stats Panel; ASHRAE TC9.9 recommended band
Average relative humidity	`avg_rh_pct`	48	%	doc-01/09 environment row; ASHRAE 40–60% band midpoint
CHW supply temperature	`chws_c`	7.2	°C	doc-09 line 15, 81–84 — canonical primary loop
CHW return temperature	`chwr_c`	14.8	°C	doc-09 line 15, 81–84 — canonical primary loop
Chillers running / total	`chillers_running / _total`	2 / 3	—	doc-01 §2 dashboard KPI "Chillers 2/3"
UPS efficiency	`ups_efficiency`	0.96	—	doc-09 line 39 ("UPS losses @ 96% efficiency 77 kW")
UPS module count (2N)	`ups_module_count`	2	—	doc-01 §Right-Side Stats Panel (UPS A / UPS B)
EPMS metering tolerance	`metering_tolerance_pct`	2	%	doc-12 line 9 "within 2%"
Fuel tank capacity	`tank_capacity_l`	60 000	L	doc-09 line 140
Tank usable fraction	`usable_fraction`	0.90	—	doc-09 line 141
Fuel level	`level_pct`	85	%	doc-09 lines 16, 126
Generator fuel consumption	`generator_consumption_lph`	956	L/hr	doc-09 lines 144–147

Accuracy rule 4: None of these values is a marketing target presented as a measured outcome. PUE 1.45 is the engineering basis from doc-09, not a best-in-class aspirational figure. The cockpit displays these as design basis chips, not live telemetry.

03 Calculation methodology

All derivations are pure functions inside CONV_CALC. Function names below map one-to-one to js/conv-engine.js. No formula exists outside the engine.

Facility and non-IT load

Facility = IT × PUE → 1 850 × 1.45 = 2 682.5 kW Non-IT = Facility − IT → 2 682.5 − 1 850 = 832.5 kW In facilityLoadKw(m), nonItLoadKw(m). Facility is the total metered input to the site; Non-IT covers cooling, lighting, UPS losses, and all ancillaries. Both are rendered on the dashboard energy panel.doc-09 lines 25–28, 32–34

PUE reconciliation

PUE = Facility / IT = 2 682.5 / 1 850 = 1.45 (identity check) The cockpit renders PUE as the ratio Facility÷IT. The locked value must always reconcile to exactly 1.45 — any other display would violate accuracy rule 1 (one source of truth). Denominator is IT load (not design capacity).doc-09 line 11; ACCURACY_VALIDATION rule 3

UPS losses

UPS loss = IT × (1/η − 1) → 1 850 × (1/0.96 − 1) = 77.1 kW Per module (2N) = UPS output / count → 1 850 / 2 = 925 kW per module In upsLossKw(m), upsModuleKw(m). In the 2N topology each module carries the full protected IT load at 100% redundancy. At 50% shared-load operating mode each module runs at 925 kW. UPS output is taken as IT load (mechanical on gen-backed switchboard, not UPS).doc-09 line 39; doc-01 §UPS A / UPS B

Chilled-water loop

ΔT = CHWR − CHWS = 14.8 − 7.2 = 7.6 K CHW flow = IT load / (Cp × ΔT) → 1 850 / (4.186 × 7.6) = 58.1 L/s Heat rejection = IT + UPS loss → 1 850 + 77.1 = 1 927.1 kW (sanity band 1 850–1 950) In chwDeltaT(m), chwFlowLps(m), heatRejectionKw(m). Cp = 4.186 kJ/(kg·K) for water. CHW flow is sized on IT load per doc-09 worked example; heat rejection (IT + UPS loss) is the cooling-band sanity check per doc-09 line 77. The secondary condenser loop (~19/22 °C) is NEVER labelled CHWS/CHWR in the cockpit — it is a distinct loop relabelled per conv-engine.js CHW basis decision.doc-09 lines 81–85; doc-00 line 83

Water usage effectiveness (WUE)

WUE = annual cooling makeup water [L] / annual IT energy [kWh] = 1.20 L/kWh Instant equivalent flow = (WUE × IT) / 60 → (1.20 × 1 850) / 60 = 37.0 L/min In waterFlowLpmForWue(m). WUE definition and reporting context follow ISO/IEC 30134-9. The cockpit shows a steady-state equivalent makeup-water rate, not a measured instantaneous flow. The display value is 37 L/min; the factor /60 converts kWh×L/kWh to L/min.doc-09 lines 99–104; ISO/IEC 30134-9:2022

Carbon usage effectiveness (CUE)

CUE = carbon emission rate [kgCO₂/hr] / IT power [kW] Carbon rate = Facility × grid factor → 2 682.5 × 0.42 = 1 126.7 kgCO₂/hr CUE (IT-basis) = grid factor × PUE → 0.42 × 1.45 = 0.609 kgCO₂/kWh-IT In carbonKgPerHr(m). CUE per ISO/IEC 30134-8 uses the facility-energy denominator for the grid carbon factor (0.42 kgCO₂/kWh is stated as a facility-energy intensity in doc-09 line 14). The IT-basis form CUE = grid factor × PUE is a derived identity. Denominator must be explicit on every CUE display (accuracy rule 3).doc-09 lines 155–158, 167; ISO/IEC 30134-8

Fuel autonomy

Usable fuel = capacity × usable fraction × fill level = 60 000 × 0.90 × 0.85 = 45 900 L Autonomy = usable fuel / generator consumption rate = 45 900 / 956 = 48.0 hr In fuelUsableL(m), fuelAutonomyHr(m). The 48 hr value is this project model's autonomy result. It does not by itself prove an Uptime Tier or universal minimum; site risk policy, refuelling logistics, generator loading and certification authority govern the required duration.doc-09 lines 132–147; project basis

Active-rack estimates

Active racks = IT load / rack density (illustrative cross-sections) At 6 kW/rack: 1 850 / 6 = 308 racks At 8 kW/rack: 1 850 / 8 = 231 racks At 10 kW/rack: 1 850 / 10 = 185 racks In activeRacks(m, kwPerRack). Three density cross-sections per doc-09 lines 51–63. Shown as informational context on the IT panel, not as primary KPIs.doc-09 lines 51–63

EPMS power metering

EPMS total = Facility load = 2 682.5 kW (nominal; tolerance band ±2%) EPMS UPS output = IT load = 1 850 kW (mechanical on gen-backed board) In epmsTotalKw(m), epmsUpsOutputKw(m). Metering tolerance ±2% is a quality flag, not an applied offset — the cockpit shows nominal values. EPMS = Electrical Power Monitoring System.doc-00 line 77; doc-12 line 9

Governed four-hall capacity study

Planning IT = 4 halls × 10 MW IT/hall = 40 MW IT Rack basis = 500 racks/hall × 20 kW/rack average = 10 MW IT/hall Design facility input = 40 MW IT × dPUE 1.45 = 58 MW at the declared 100% design point The separately frozen RZConvDesignBasis.STUDY owns this document-only planning scope. Its thermal contract is chilled-water CRAH / air cooling with a project rack-inlet target of 25.4 °C, inside the ASHRAE recommended 18–27 °C envelope. Air properties are evaluated at 25.4 °C, 101.325 kPa and 50% RH with c_p = 1.006 kJ/(kg·K); heat rejection is an evaporative cooling-tower study. A 200-rack/hall option implies 50 kW/rack and therefore fails this air-cooling contract. The study never replaces the current 1,850 kW snapshot. dPUE 1.45 is valid only at the declared design point; off-design facility power remains unavailable until an approved monotonic part-load curve exists.

04 Constants & data sources

Every constant lives in the deep-frozen CONV_MODEL object with a // source: tag pointing to conv review doc line numbers. The snapshot table confirms all computed intermediates at the locked basis point.

Computed quantity	Function	Result	Unit
Facility load	`facilityLoadKw()`	2 682.5	kW
Non-IT load	`nonItLoadKw()`	832.5	kW
UPS loss	`upsLossKw()`	77.1	kW
CHW ΔT	`chwDeltaT()`	7.6	K
CHW flow	`chwFlowLps()`	58.1	L/s
Heat rejection	`heatRejectionKw()`	1 927.1	kW
UPS per-module load	`upsModuleKw()`	925.0	kW
Water makeup flow	`waterFlowLpmForWue()`	37.0	L/min
Carbon emission rate	`carbonKgPerHr()`	1 126.7	kgCO₂/hr
Usable fuel	`fuelUsableL()`	45 900	L
Fuel autonomy	`fuelAutonomyHr()`	48.0	hr

Accuracy rule 2: None of these values involves Math.random(). Every number is stable on reload, reproducible in Node, and verifiable against tools/test-conv-calc.mjs (22/22 DoD identities).

05 Outputs & cockpit panels

The cockpit surfaces these derived quantities across its dashboard, EPMS, cooling, water, fuel, and sustainability panels. Each KPI carries a basis chip citing its source.

KPI	CONV_CALC function	Unit	Panel
IT load	`model.site.it_load_kw`	kW	Energy dashboard
Facility load	`facilityLoadKw()`	kW	Energy dashboard / EPMS total
Non-IT load	`nonItLoadKw()`	kW	Energy breakdown
PUE	Facility / IT (identity)	—	Sustainability header
WUE	`model.environment.wue_l_per_kwh`	L/kWh	Sustainability / water panel
CUE (IT-basis)	grid factor × PUE	kgCO₂/kWh-IT	Sustainability panel
Carbon rate	`carbonKgPerHr()`	kgCO₂/hr	Sustainability panel
UPS loss	`upsLossKw()`	kW	EPMS electrical panel
UPS per-module kW	`upsModuleKw()`	kW	EPMS UPS A / UPS B gauges
CHW supply / return	`model.cooling.chws_c / chwr_c`	°C	Cooling panel — primary loop only
CHW ΔT	`chwDeltaT()`	K	Cooling panel
CHW flow	`chwFlowLps()`	L/s	Cooling panel
Heat rejection	`heatRejectionKw()`	kW	Cooling sanity band
Chillers running / total	`model.cooling.chillers_*`	—	Cooling panel status
Water makeup flow	`waterFlowLpmForWue()`	L/min	Water panel
Fuel level / usable	`model.fuel.level_pct / fuelUsableL()`	% / L	Fuel panel gauge
Fuel autonomy	`fuelAutonomyHr()`	hr	Fuel panel — 48 hr project/model result
Active racks (3 densities)	`activeRacks(m, kW)`	count	IT capacity panel
Avg temperature / RH	`model.environment.avg_temp_c / avg_rh_pct`	°C / %	Environment panel
EPMS metering tolerance	`model.electrical.metering_tolerance_pct`	%	EPMS quality chip
Current Design Studio snapshot	`CONV_CALC.snapshot`	kW	Current scope: locked 1,850 kW IT basis only
Four-hall capacity appendix	4 × 10 MW IT; 500 racks/hall; 20 kW/rack average	MW IT / rack / kW·rack⁻¹	Current-plus-study scope: governed 40 MW planning reference, non-adopted

Release acceptance	Executable evidence	Required invariant
Locked calculation chain	`tools/test-conv-calc.mjs`	The current snapshot retains the 1,850 kW IT basis and all documented identities.
Design Studio scopes	`tools/test-rz-design-studio.mjs` plus browser/PDF journey	Current excludes 40 MW; current-plus-study adds a non-adopted appendix without mutating `CONV_CALC.snapshot`.
EPMS source truth	`tools/test-epms-ats-rack-color.mjs`	Normal, tie and generator scenarios derive the final ATS-to-rack conductor from its actual energizing source.
Accessible document flow	Keyboard and dialog browser journey	Labeled controls, focus trap, Escape/scrim/close and trigger-focus return remain intact; failures are visible.

06 Worked example — 1 850 kW scenario

Full derivation chain reproducing every primary KPI on the simulated cockpit exactly. All figures match CONV_CALC.snapshot.

Facility load: 1 850 × 1.45 = 2 682.5 kW
Non-IT load: 2 682.5 − 1 850 = 832.5 kW
PUE reconciliation: 2 682.5 / 1 850 = 1.45 ✓ (identity holds)
UPS loss: 1 850 × (1/0.96 − 1) = 77.1 kW · per module (2N): 1 850 / 2 = 925.0 kW
CHW ΔT: 14.8 − 7.2 = 7.6 K · CHW flow: 1 850 / (4.186 × 7.6) = 58.1 L/s
Heat rejection: 1 850 + 77.1 = 1 927.1 kW — within design band 1 850–1 950 kW ✓
WUE check: 1.20 L/kWh (basis) · instant makeup flow: (1.20 × 1 850) / 60 = 37.0 L/min
Carbon rate: 2 682.5 × 0.42 = 1 126.7 kgCO₂/hr · CUE (IT-basis): 0.42 × 1.45 = 0.609 kgCO₂/kWh-IT
Usable fuel: 60 000 × 0.90 × 0.85 = 45 900 L · Autonomy: 45 900 / 956 = 48.0 hr (project/model result; no certification inference)
Active racks at 8 kW/rack: 1 850 / 8 = 231 racks

Engineering reading: the cockpit operates at 92.5% of its current modeled IT design capacity (1 850/2 000 kW). PUE 1.45 and 48 hr autonomy are declared scenario values, not universal quality grades, code baselines or Tier evidence. Operational targets require an approved metering boundary, load profile, climate basis, risk policy and certification review.

07 References & standards

conv review doc 09 — 09-engineering-basis-and-calculations.md: primary source for all scenario constants (IT load, PUE, WUE, CHW loop, UPS efficiency, fuel system). Line numbers cited throughout.
ASHRAE 90.1 — Energy Standard for Buildings: PUE benchmarks and baseline cooling-system design parameters for conventional chilled-water data centres.
ASHRAE TC9.9 — Thermal Guidelines for Data Processing Environments: cold-aisle temperature and RH recommended bands (A1/A2 class).
Uptime Institute Tier Standard — topology and concurrently-maintainable design intent; the cockpit does not claim certification or infer a universal fuel duration.
ISO/IEC 30134-2:2026 — Data-centre Power Usage Effectiveness (PUE) definition and reporting boundary.
ISO/IEC 30134-9:2022 — Water Usage Effectiveness (WUE) definition, measurement categories, calculation and reporting interpretation.
ISO/IEC 30134-8 — Key Performance Indicators for Data Centres — Part 8: Carbon Usage Effectiveness (CUE). Denominator = IT energy; grid carbon factor applied at facility-energy basis per doc-09 line 14.
Engine source — js/conv-engine.js (CONV_CALC v1.0.0 + CONV_MODEL, deep-frozen). Gate: tools/test-conv-calc.mjs (22/22 DoD identities).
Accuracy gate — tools/probe-accuracy-validation.mjs (40/40 acceptance tests, 6 accuracy rules). Must pass before any cockpit change ships.
Design-document source — js/rz-design-studio.js governs shared document type/scope validation and accessible dialog state; dc-conventional.html supplies the current snapshot and non-adopted 4 × 10 MW study appendix.
Electrical topology source — EPMS_Telemetry.html owns modeled source selection and the final ATS-to-rack conductor class; regression evidence is tools/test-epms-ats-rack-color.mjs.
ISA-18 alarm-management series — lifecycle, operator response and rationalization context for future alarm-management work.
IEC 62682:2022 — alarm-management terminology and acceptance context; inclusion is not a conformance claim.

08 Assumptions & limitations

The cockpit models a single fixed engineering scenario. It is not a design calculator and cannot be parameterised. Key assumptions and scope boundaries:

CHW loop: Only the primary (secondary) chilled-water loop at 7.2/14.8 °C is surfaced. The condenser-side loop operating at ~19–23 °C is out of scope for this cockpit and is never labelled CHWS/CHWR (conv-engine.js CHW basis decision). Secondary pump losses and free-cooling economiser modes are not modelled.

UPS topology: The 2N model assumes equal load sharing across both modules at 925 kW each. Single-module fault scenarios and static bypass paths are not modelled.

Fuel consumption: 956 L/hr is the generator consumption at approximately 2.7 MW facility load (generator output ≈ non-IT + IT generation, accounting for prime-move fuel burn curve). It is an engineering estimate for sizing, not a live meter reading.

WUE and water flow: The 37 L/min figure is the steady-state equivalent evaporative makeup rate derived from the annual WUE target. Actual instantaneous cooling-tower blowdown, drift loss, and basin makeup vary with ambient wet-bulb temperature. This cockpit displays the design-point equivalent only.

Carbon intensity: 0.42 kgCO₂/kWh is a fixed grid-average factor from the engineering basis. Real-time grid decarbonisation, marginal emissions, and Scope 2 market-based accounting are out of scope.

Capacity planning: Four halls at 10 MW IT each is a 40 MW IT planning brief only, governed by js/conv-design-basis.js. It assumes 500 air-cooled racks per hall at 20 kW average (30 kW selected peak), chilled-water CRAH cooling, evaporative cooling-tower heat rejection and the declared subsystem resilience intent. It is not installed, energized, commissioned, measured or represented by the current 1,850 kW telemetry snapshot.

Design-point efficiency: 1.45 is a dPUE input at 100% study load, not a part-load performance curve and not a claim of annual measured PUE. Off-design study facility power fails closed until an approved monotonic curve is supplied. The current cockpit PUE remains the independent 1.45 modeled snapshot ratio.

Design Studio: The current scope is generated only from the captured CONV_CALC.snapshot. The current-plus-study scope appends the reconciled design basis from RZConvDesignBasis.STUDY; changing scope does not change cockpit data.

This manual and the cockpit are an engineering education and operational reference aid. They do not substitute for a live DCIM/EPMS/BMS with calibrated sensors, metered telemetry, and alarm setpoints set by a qualified controls engineer to the site authority having jurisdiction.

09 Cockpit controls & telemetry map

The dashboard is a facility overview rather than a command HMI. Its controls navigate, explain or report the locked scenario; none writes to BMS/EPMS equipment.

Control / surface	Hook	Expected behavior	Data or safety boundary
Portfolio / DC Solutions / PRD / Manual	`.back-btn`	Navigate without changing `CONV_CALC.snapshot`.	PRD and Manual are public; cockpit access remains tier-controlled.
Generate Design / Design Studio	`genDesignTrigConv`, `RZDesignStudio`	Open the shared dialog, show captured snapshot/provenance, and select current or current-plus-study before generating the approved document type.	The appendix is non-adopted and cannot mutate current values; focus is trapped and returned, and generation failure remains visible.
FAQ	`faqTrigConv`	Open ten explanatory questions; close by button, scrim or Escape.	Answers disclose locked, simulated and non-procurement scope.
Theme	`themeToggle`	Switch/persist light or dark theme.	Never changes values or threshold results.
Subsystem routes	`.nav-menu-item`	Open EPMS, Data Hall, Chiller, Fire, Fuel, Water or ICT pages.	Status copy in this overview is not a substitute for subsystem detail.
EPMS source-truth path	`w_ats_rack_*` in `EPMS_Telemetry.html`	Carry the actual selected source state through the ATS and its final rack conductor in normal, tie and generator scenarios.	Feed A is red/A and Feed B is green/B; source/state text supplements color, and no click issues a field command.
Alarm strip	`alarmStrip`	Show overall state, critical, warning, maintenance/bypass, comms, stale, last update, quality and scenario first.	Counts are evaluated from a frozen model; Last Update is browser time.
PUE basis	`.kpi-card[data-basis="pue"]`	Open formula, IT/facility/non-IT inputs, output, scope, denominator and source.	1.45 is derived from the model; ≤1.5 is a target.
WUE basis	`data-basis="wue"`	Explain annual definition, IT denominator and 37.0 L/min equivalent makeup.	Equivalent steady-state rate is not an instantaneous tower meter.
Grid-factor basis	`data-basis="grid"`	Separate 0.42 kgCO₂/kWh facility from CUE_IT.	Factor needs geography/date/version before reporting.
IT-load basis	`data-basis="it"`	Show 1,850/2,000 kW and 92.5% utilization.	Locked BOD, not a meter stream.
Uptime basis	`data-basis="uptime"`	Explain 99.98% and Tier intent.	Explicit design placeholder; no outage ledger is bound.
Temperature basis	`data-basis="temp"`	Explain 22.4°C against the referenced thermal band.	Simulated aggregate, not a sensor roll-up.
Chiller basis	`data-basis="chillers"`	Explain 2/3 operation and one spare.	Standby capacity is not automatically a maintenance/bypass event.
KPI keyboard path	`.kpi-card[data-basis]`	Enter/Space opens; Escape, scrim and Close dismiss; focus returns.	All meaning remains textual, not color-only.
Facility image callouts	`cPue`, `cIt`, `cChw`, `cTemp`, `cFuel`, `cRh`	Show the six operational values on their physical context image.	Image is contextual; right panel and basis drawers are authoritative for scope.
Right statistics panel	`s*` IDs plus static rows	Group Efficiency, Power, Cooling, Reliability, Environment, Safety and Fuel.	Engine-bound and static presentation rows must remain visibly distinguishable.
Scroll to top	`scrollTopBtn`	Return to header without changing the scenario.	Respect reduced-motion preference.
Sign in	`rootLoginBtn` / shared gate	Open the shared authentication/upgrade flow for an unauthorized cockpit user.	It grants no access to public docs because they are already public.

10 Alarm, quality & operating interpretation

Primary arithmetic is deterministic. Several context rows remain static placeholders. The following map prevents a reader from assigning the same trust level to both classes.

Point family	Representative hook	Source class	Interpretation / threshold
PUE / WUE / grid / IT / facility	`kpiPue`, `kpiWue`, `kpiCarbon`, `kpiIt`, `sTotalLoad`	Locked or derived from `CONV_CALC.snapshot`.	Stable on reload; PUE warns above 1.5.
CHWS / CHWR / environment / fuel	`sChwSup`, `sChwRet`, `sTempAvg`, `sRhAvg`, `sFuelMain`	Locked BOD/simulated aggregate.	Temperature warns outside 18–27°C and critical above 32°C; RH warns outside 20–80%; fuel warns below 24 h and critical below 12 h autonomy.
Maintenance / bypass	`as-maint`	Derived as 3 installed − 2 running chillers.	Current value 1 means available standby in this model, not proven maintenance activity.
Comms / stale	`as-comms`, `as-stale`	Model-integrity check.	Comms OK means a versioned local snapshot exists; stale 0 means the frozen scenario has no acquisition-age concept.
Last Update	`as-update`	Browser clock.	Display time, not field sample time.
UPS A/B	`sUpsA`, `sUpsB`	Derived load with local 2,000 kW/module display rating.	46% normal shared / 92% failover; move the rating to the immutable model before design reliance.
Chillers / CRAHs	CH-1, CH-2, Chillers, CRAHs rows	Mixed: count from snapshot; unit percentages and CRAH 12/14 are static.	Do not treat static percentages as trended sensor values.
Network / topology / uptime	Network, UPS Topology, Uptime rows	Static modeled state / placeholder.	Online and 2N OK are overview claims; 99.98% is not event-derived.
Environment DP	DP +2.1 Pa row	Static presentation.	No pressure-sensor source, timestamp or alarm threshold is currently bound.
FACP / VESDA	Safety rows	Static presentation.	Normal state is not proof of detector, panel, cause-effect or suppression compliance.
Day tank	Day Tank 92% row	Static presentation.	Bulk-tank 85%/48 h arithmetic does not validate this separate buffer value.
Data Quality / Scenario	`as-dq`, `as-scn`	Snapshot metadata.	GOOD describes internal model availability; Simulated is the governing provenance.
EPMS final rack path	`w_ats_rack_*`	Modeled topology state in `EPMS_Telemetry.html`.	The conductor inherits its actual energizing source; red/green never replaces source and energized-state text.
Four-hall planning appendix	Design Studio current-plus-study	Frozen document-only study.	4 × 10 MW = 40 MW IT, 500 racks/hall and design-point dPUE remain outside current telemetry and outside `CONV_CALC.snapshot`.

Alarm sequence: critical count has priority over warning. The current model does not implement acknowledgement, shelving, suppression, cause/effect or an event historian. A future field implementation should follow the ISA-18 series and IEC 62682:2022, with point-level freshness and quality. These references define direction and terminology, not current conformance.

11 Glossary & RZExplain

Marked terms are discoverable through the shared RZExplain scanner. Definitions below use the exact denominator and scope implemented by this cockpit.

Term	Cockpit meaning	Common misread
PUE	Facility power / IT power = 2,682.5 / 1,850 = 1.45.	Target efficiency or cooling-only ratio.
WUE	Annual cooling makeup water litres / annual IT kWh = 1.20 L/kWh.	All site water or instantaneous tower flow.
CUE	Carbon per IT energy = grid factor × PUE = 0.609 kgCO₂/kWh IT.	The raw 0.42 facility-kWh grid factor.
CHWS / CHWR	Primary chilled-water supply/return at 7.2/14.8°C.	The separate ~19/23°C condenser/warm-water loop.
EPMS	Electrical Power Monitoring System; route from the subsystem rail.	A control authorization or protection study.
BMS	Building Management System context for cooling/environment/safety integration.	A live field connection in this page.
2N	Two independent UPS paths, each able to carry the protected load.	Two modules whose combined capacity alone meets load.
Facility load	All site input power inside the PUE boundary.	IT output alone.
Non-IT load	Facility − IT = cooling, losses and auxiliary demand.	Only chiller compressor power.
Locked / derived / placeholder	Immutable assumption / formula output / value awaiting authoritative history or sensor source.	Equivalent forms of live telemetry.