Generator Sizing Calculator (backup power) implementation

Binding contract

This record describes what an executable surface must bind and validate. It does not claim that a public calculator, package, or production route is deployed.

Record owner

Guth Instruments

Lifecycle

verified-clean

Evidence ID

t7-126

Effect

Computation or source lookup only

Input and validation requirements

The specification does not define overflow handling, has no explicit unit-normalization rule, and does not state the recommended-size margin. Extreme inputs can become non-finite, while the same unit-ambiguous entry can produce 5000 W or 504.5 W.

Required corrections

No binding erratum is attached to this unique-name record. Implementers must still preserve the declared units, domain, and failure behavior.

Inspectable interface fixture

The sample below is evidence for interface and validation tests, not a production implementation.

{
  "inputs": {
    "loads": [
      {
        "name": "resistive heater",
        "voltage_v": 120,
        "current_a": 10,
        "power_factor": 1,
        "running_w": 1200,
        "starting_w": 1200
      }
    ]
  },
  "expected_outputs": {
    "total_running_w": 1200,
    "peak_starting_w": 1200,
    "recommended_generator_size_w": null
  },
  "reference_data": {
    "nominal_single_phase_voltage_v": 120,
    "source_convention": "ANSI C84.1 nominal U.S. utilization-voltage convention",
    "unity_power_factor": 1,
    "source_convention_pf": "ideal resistive-load convention; not a lookup-table uncertainty"
  },
  "working": "Running power = V × I × PF = 120 V × 10 A × 1 = 1200 W. Total running = 1200 W. Incremental startup surge = starting - running = 1200 - 1200 = 0 W. Peak starting = total running + maximum incremental surge = 1200 + 0 = 1200 W. Recommended size is undefined because the specification gives no reserve or rounding rule."
}

Other records

Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

• VERIFIED_LEDGER.json
• evidence-tranche7/tranche7-results.json