Source: https://guthlabs.ai/docs/instruments/electrical-safety-shock-current-reference/

instrument / verified-clean

# Electrical Safety / Shock Current Reference

The current ledger marks this instrument verified clean within the source-bound verification corpus.

Status: **VERIFIED_CLEAN**Lifecycle: **verified-clean**

## Inspectable records

[01**Overview**Purpose and lifecycle](<https://guthlabs.ai/docs/instruments/electrical-safety-shock-current-reference/>)[02**Mechanism**Method and assumptions](<https://guthlabs.ai/docs/instruments/electrical-safety-shock-current-reference/mechanism/>)[03**Implementation**Binding and validation](<https://guthlabs.ai/docs/instruments/electrical-safety-shock-current-reference/implementation/>)[04**Qualification**Evidence and errata](<https://guthlabs.ai/docs/instruments/electrical-safety-shock-current-reference/qualification/>)

## Ledger state

The current ledger marks this instrument verified clean within the source-bound verification corpus.

**Area**: Electrical & Electronics Engineering — Circuits, Power Systems, Electronics Lab

**Tranche**: tranche-7

**Evidence ID**: t7-113

**Ledger rows**: 1

No ledger note is attached.

## Review findings

NEEDS_REVIEW because the claimed IEC 60479 comparison is underspecified and the supplied algorithm omits the standard's waveform, frequency, current path, and duration-dependent assessment. The four vectors are valid only for the explicitly stated Ohmic, 50/60-Hz RMS AC approximation and the simplified educational boundaries. Retain the educational-only warning and require lockout/tagout and applicable electrical codes rather than using this instrument for live-work or safety-certification decisions.

### Formula and scope findings

- I=V/Rbody is correct for an Ohmic body-resistance approximation, with voltage and resistance expressed in compatible units.

- The specification does not identify AC versus DC, frequency, waveform, current path, contact area, or whether the voltage is RMS or peak; IEC 60479-1 thresholds depend on these conditions.

- Fixed current bands are not a complete IEC 60479-1 method: the standard uses current-duration zones and physiological effects, including fibrillation-probability zones, rather than a universal hazard classification based only on current.

- The commonly used simplified 50/60-Hz AC boundaries of 0.5 mA, 10 mA, and 30 mA are educational shorthand and must not be labeled as a full IEC 60479-1 compliance calculation.

- Duration is an input but is ignored by the stated classification algorithm; this is technically inadequate for the claimed current-duration threshold reference.

- The claimed 'touch-voltage estimate' is actually just the supplied voltage unless a separate voltage-drop or contact-voltage model is specified.

### Unit assumptions

- Voltage is touch voltage in volts RMS for a sinusoidal 50/60-Hz AC source.

- Body resistance is in ohms and represents the complete hand-to-hand or hand-to-foot current path; it is treated as constant during the contact.

- Current is calculated as amperes by I=V/R and also reported in milliamperes using 1 A=1000 mA.

- The test classification uses the simplified educational convention: AC-1 for I≤0.5 mA, AC-2 for 0.5 mA<I≤10 mA, AC-3 for 10 mA<I≤30 mA, and AC-4 for I>30 mA.

- The simplified classification is evaluated at the stated current and does not claim to reproduce the full IEC 60479-1 current-duration zones.

- A zero-resistance input is invalid because it causes division by zero; zero voltage with positive resistance is valid and produces zero current.

## Boundary hardening

**BREAK_CLAIMED** · SELF_FLAGGED

A zero body-resistance input produces an undefined division result and must be rejected. The reference profile is also under-specified because the actual IEC 60479-1 table, waveform, frequency, current path, and duration-dependent thresholds are not supplied; the branch classifications above therefore use explicitly labeled illustrative thresholds rather than constituting a safety certification.

## Errata and corrections

No applied erratum is attached to this unique-name record.

## Inspectable example

4 review vectors are recorded. One source-bound sample is shown below.

````
{
  "inputs": {
    "voltage_V": 120,
    "body_resistance_ohm": 100000,
    "duration_s": 1,
    "waveform": "50/60-Hz sinusoidal AC assumed"
  },
  "expected_outputs": {
    "touch_voltage_V": 120,
    "estimated_current_A": 0.0012,
    "estimated_current_mA": 1.2,
    "hazard_band": "AC-2: above 0.5 mA through 10 mA in the simplified educational convention"
  },
  "reference_data": {
    "perception_boundary_mA": 0.5,
    "let_go_boundary_mA": 10,
    "severe_contraction_boundary_mA": 30,
    "source_convention": "Widely tabulated standard value, simplified 50/60-Hz AC educational shorthand; not a complete normative IEC 60479-1 table",
    "classification_rule": "AC-1 if I≤0.5 mA; AC-2 if 0.5 mA<I≤10 mA; AC-3 if 10 mA<I≤30 mA; AC-4 if I>30 mA"
  },
  "working": "I=V/R=120 V/100000 Ω=0.0012 A. Convert to milliamperes: 0.0012 A×1000=1.2 mA. Since 0.5 mA<1.2 mA≤10 mA, the simplified classification is AC-2. The supplied touch voltage is 120 V."
}
````

## Related workflows

No source-defined multi-instrument workflow membership is recorded.

## Sources and evidence

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

- `VERIFIED_LEDGER.json · VERIFIED_CLEAN`

- `evidence-tranche7/tranche7-results.json`

- `BOUNDARY_HAZARD_CATALOG.json`