{
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  "engine": "watts-va",
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  "engine_build": "2026-09-10",
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  "passed": 16,
  "failed": 0,
  "tests_summary": {
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      "passed": 9
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    "boundary": {
      "total": 2,
      "passed": 2
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    "property": {
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  "expert_reviewed": false,
  "internally_reviewed": false,
  "review_kind": null,
  "source_checked": true,
  "reviewed_by": null,
  "reviewer_role": null,
  "last_reviewed": null,
  "expert_review": {
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    "reviewer": null,
    "scope": [
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      "input semantics",
      "assumptions",
      "limitations",
      "sources",
      "tests"
    ],
    "note": "Domain expert review is optional under CVP (CVP-EXP-01). Absence does not block CVP Verified. See Review policy for supplemental domain assurance."
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  "schema_input": "https://www.calculatorx.com/schemas/electrical.watts_to_va.input.json",
  "schema_output": "https://www.calculatorx.com/schemas/electrical.watts_to_va.output.json",
  "assumptions": [
    "PF in (0, 1] — required (not optional)",
    "No voltage/phase required once P (or S) and PF are known"
  ],
  "limitations": [
    "Not for voltage/current→VA (use amps-to-va)",
    "PF must be in (0, 1] — PF=0 → POWER_FACTOR_OUT_OF_RANGE (not a soft zero)",
    "Roadmap model op: real_from_S_pf / apparent_from_P_pf"
  ],
  "boundary_conditions": [
    "PF ≤ 0 or > 1 → POWER_FACTOR_OUT_OF_RANGE",
    "Missing PF → MISSING_REQUIRED_INPUT",
    "Zero watts/VA with valid PF → 0",
    "API: mode w-va|va-w; a|P|S; b|power_factor; optional factor"
  ],
  "sources": [
    {
      "title": "IEC 60050 — International Electrotechnical Vocabulary",
      "section": "Apparent power (IEV 131-11-41)",
      "url": "https://www.electropedia.org/iev/iev.nsf/display?openform&ievref=131-11-41",
      "supports": "S (VA) is apparent power; distinct from active power P (W); unit volt-ampere (VA)",
      "kind": "standard",
      "accessed": "2026-09-05",
      "clause": "IEV 131-11-41"
    },
    {
      "title": "IEC 60050 — International Electrotechnical Vocabulary",
      "section": "Power factor (IEV 131-11-46)",
      "url": "https://www.electropedia.org/iev/iev.nsf/display?openform&ievref=131-11-46",
      "supports": "λ = |P| / S; S = P / λ and P = S × λ",
      "kind": "standard",
      "accessed": "2026-09-05",
      "clause": "IEV 131-11-46"
    },
    {
      "title": "IEEE Std 1459-2025",
      "section": "Apparent power from real power and power factor",
      "url": "https://standards.ieee.org/ieee/1459/7578/",
      "supports": "S(VA) = P(W) / PF; P = S × PF",
      "kind": "standard",
      "accessed": "2026-09-05",
      "publisher": "IEEE",
      "published": "2025-05-16",
      "errata_checked": true
    },
    {
      "title": "BIPM SI Brochure (9th edition, version 4.01)",
      "section": "SI units for watt and volt-ampere",
      "url": "https://www.bipm.org/en/publications/si-brochure",
      "supports": "W and VA unit relationships",
      "kind": "reference",
      "accessed": "2026-09-05",
      "published": "2026-06",
      "doi": "https://doi.org/10.59161/AUEZ1291"
    },
    {
      "title": "NIST Guide to the SI (SP 811)",
      "section": "Watt and volt-ampere",
      "url": "https://www.nist.gov/pml/special-publication-811",
      "supports": "SI power unit relationships",
      "kind": "reference"
    }
  ],
  "methods": [],
  "fingerprint": "sha256:bb77c72a7e6a3706c4f972d201d7105ddf1bd94157d14ddaacba60c8adcc7063",
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      "kind": "golden",
      "inputs": {
        "mode": "w-va",
        "a": 1000,
        "b": 0.8,
        "factor": 1
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      "expect": 1250,
      "expectWarning": null,
      "actual": 1250,
      "tol": 0.1
    },
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      "id": "500W-0.67",
      "ok": true,
      "kind": "golden",
      "inputs": {
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        "a": 500,
        "b": 0.67,
        "factor": 1
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      "expect": 746.2687,
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        "factor": 1
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      "tol": 0.1
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      "tol": 0.1
    },
    {
      "id": "linear-2x-w",
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      "kind": "golden",
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        "a": 2000,
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        "factor": 1
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      "expect": 2500,
      "expectWarning": null,
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      "tol": 0.1
    },
    {
      "id": "inverse-half-pf",
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      "kind": "golden",
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        "b": 0.4,
        "factor": 1
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      "expect": 2500,
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      "actual": 2500,
      "tol": 0.1
    },
    {
      "id": "hard-zero-pf",
      "ok": true,
      "kind": "boundary",
      "inputs": {
        "mode": "w-va",
        "a": 1000,
        "b": 0,
        "factor": 1
      },
      "expectError": "POWER_FACTOR_OUT_OF_RANGE",
      "code": "POWER_FACTOR_OUT_OF_RANGE",
      "error": "power_factor must be in (0, 1]"
    },
    {
      "id": "soft-zero-w",
      "ok": true,
      "kind": "golden",
      "inputs": {
        "mode": "w-va",
        "a": 0,
        "b": 0.8,
        "factor": 1
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      "expect": 0,
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      "actual": 0,
      "tol": 1e-12
    },
    {
      "id": "5000W-0.9",
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      "expect": 5555.5556,
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      "expectError": "MISSING_REQUIRED_INPUT",
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      "error": "power_factor is required"
    },
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      "id": "property-w-va",
      "ok": true,
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      "detail": "1000 W / 0.8 → 1250 VA",
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    },
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      "detail": "VA→W recovers P",
      "expect": 1000,
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      "ok": true,
      "kind": "property",
      "detail": "P/power_factor ≡ a/b",
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      "actual": 1250
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