Research — Auto Demo · Precomputed (draft, unvalidated)

Grounding grid: touch and step — auto

No controls here: six short stories play on their own, and a fault pulse floods the grid at every step. A 50 kg person has a lower tolerable limit than a 70 kg one. Crushed rock raises the limits without touching the grid. A faster relay raises the tolerable limits. A denser grid cuts the mesh voltage. Poor soil raises the voltages much faster than the limits, and more fault current raises every computed voltage while the limits stay put. Use Pause, or the story and step buttons, to stop on any frame.

Story

Draft, unvalidated harness (no SME sign-off) · illustrative geometry: a generic 60 m square grid, not any real station · the shading over the plan is illustrative (the harness has no spatial-profile function).

Anchoring limits, verbatim from the data file

DRAFT, UNVALIDATED harness. Illustrative substation grid (60 m x 60 m square, 0.01 m conductor, 0.5 m depth, 3 m rods on the perimeter, split factor 0.6, X/R 20, crushed rock 2000 ohm-m 0.10 m): not any real station. Clearing time is used for both the decrement factor and the shock duration. The functions compute values and never judge; 'exceeds_limit' / 'within_limit' is this demo's own comparison (src 'demo-logic'). The harness anchors: Numerically validated against a real published example (Ma, Dawalibi & Southey, "Effects of the Changes in IEEE Std. 80..."): X/R=20, tf=0.5s, f=60Hz reproduces the paper's published Df=1.052 to within its own rounding. Numerically validated against a real published example (Ma, Dawalibi & Southey, "Effects of the Changes in IEEE Std. 80..."): rho=100, rho_s=2000, hs=0.10 reproduces the paper's published Cs=0.705 (2000/2013-edition formula) to three significant figures. Everything else is self-consistency only: No IEEE 80-2013 Annex worked-example numeric results were recovered.** `GROUNDING_KICKOFF.md`'s own suggested validation path (the 2/0 AWG / 0.5m depth / 7.5m rod "Grid 1/2/3" benchmark cases, one uniform 140 ohm-m soil, one two-layer 300-over-100 ohm-m soil) is real and confirmed to exist, but every source checked for the actual computed Rg/GPR/Em/Es results was paywalled or dead. **Rg, Km, Ks, Em, and Es are therefore validated only by hand-derived self-consistency tests** (the test recomputes the same cited formula independently of the implementation, catching transcription/arithmetic bugs, but not confirming the formula itself against a real published result). Do not treat any of these five outputs as production-validated until either the standard itself or a CDEGS/XGSLab benchmark report is obtained and used to build a real regression test. Until these are resolved, treat every result from these functions as a draft, first-pass indicator, not validated input to a downstream compliance decision. No spatial potential-profile function exists in the harness, so the profile shading the UI draws is illustrative. Axes: spacing_m (60 m side / spacing = mesh cells), rods, rho_ohm_m, fault_a (symmetrical SLG current), clear_s, rock (0/1). Cols em_gt_* / es_gt_* are 0/1 comparisons made by the exporter (demo-logic); 50 kg and 70 kg limits are both in every cell.

Plan · conductors and rods to scale, shading illustrative

The shading is illustrative: its levels are pinned to the exported voltages, its shape is not computed. The dashed grey contour marks the tolerable touch voltage for the chosen body weight. Corner meshes have the deepest dips, so the peak sits there.

Section · soil layers, person, touch and step paths

Computed voltage against the tolerable limit

Bars are neutral. The hatched part is how far past the solid tick the bar reaches, shown only where the exporter’s comparison says “exceeds the limit”.

Live readout · the cell or step on screen

Assumptions: the fixed illustrative inputs

    Every check at this step · rows where the exporter's comparison says “exceeds the limit” are highlighted

    Rule column: the citation the data file gives for each check.

    How the checks read it

    Every check · first step, a middle step, the last step of the story

    Columns are named by the story's own steps. Every value is read from the data file; the comparison wording is the exporter's own, never a harness verdict.

    Precomputed results:every verdict, required value and margin on this page was computed by the real Python harness at export time and is played back from a data file. The page runs no harness logic and holds no standards tables, and it never interpolates between exported values. Not a live API call. Precomputed by the real functions calculate_grounding_grid_resistance, calculate_ground_potential_rise, calculate_mesh_and_step_voltage, calculate_surface_layer_derating_factor and calculate_tolerable_touch_step_voltage in circuit-calc-harness (recorded commit 2589b99), a draft, unvalidated harness. The decrement factor and the surface-layer factor each match one published point; no IEEE 80 Annex worked example exists for the whole chain. Every verdict in the file is "value"; "exceeds the limit" and "within the limit" are this demo's own comparison of two harness values. The grid is a generic 60 m square with fixed illustrative inputs, not any real station. The shading and the potential profile are illustrative.Real functions this maps to:calculate_grounding_grid_resistance, calculate_ground_potential_rise, calculate_mesh_and_step_voltage, calculate_surface_layer_derating_factor, calculate_tolerable_touch_step_voltage.Not modeled: a real station, irregular grids, two-layer soil beyond one crushed-rock layer, the fence touch voltage and any voltage outside the grid, transferred potential, and any spatial potential-profile function. Rod positions, equipment pads and the potential shape in the drawing are illustrative.See also:Grounding grid, interactive with free play · Fault current, hands-off