Calculator #003 IEEE Std 80-2013 IEC 61936-1 Multi-grid Sketch editor

Substation Grounding Grid Calculator — IEEE Std 80

Multi-grid sizing of a substation earthing grid per IEEE Std 80-2013 (with cross-reference to IEC 61936-1 §10 and IEC TS 60479-1). Conductor sizing (§11), tolerable touch / step voltages (§8), grid resistance (Sverak Eq 53 and Schwarz Eq 56–58), maximum mesh and step voltages (Eq 84–93), uniform or two-layer soil. Each tab is an alternative grid layout — parametric or sketched on a 1 m grid. All computation runs in your browser — no data leaves the page.

Developed by the ieccalc.com engineering team

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Project settings (applied to all grid scenarios)

Region & body criteria

Region preset

Body weight assumption (IEEE 80 §8)

System frequency, Hz

Surface insulating layer

Fault current & timing

Earth fault current I_f, kA (RMS sym.)

Fault clearing time t_f, s (for D_f, conductor)

Shock duration t_s, s (touch/step)

X / R ratio at fault location

Current division S_f (0–1)

Future projection C_p

Surface resistivity ρ_s, Ω·m

Surface thickness h_s, m

Lightning protection (LPS)

Lightning protection level (IEC 62305-1)

Lightning equivalent t_c, s

Conductor material & ambient

Conductor material (IEEE 80 Table 1)

Joint type → max temp T_m

T_m, °C (joint)

Ambient T_a, °C

Acceptance criteria — R_g target (project / utility)

Installation type / Utility code

Use normative R_target

R_target, Ω

Reference

Safety factors & numerical tolerances

K_touch (touch margin)

K_step (step margin)

K_conductor (thermal margin)

K_Rg (R_target margin)

Solver consistency tolerance, %

Current balance tolerance, %

Equipotential tolerance, %

Map / segment sensitivity, %

Surface layer derating C_s = 1 − 0.09·(1 − ρ/ρ_s)/(2·h_s + 0.09) — IEEE 80 Eq (27). Tolerable voltages use 0.116 / √t_s (50 kg) or 0.157 / √t_s (70 kg). Soil ρ / ρ_1 / h_1 / ρ_2 are set per scenario in each grid tab.

PRO — sketch editor, maps and the full report

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Glossary & abbreviations

Numerical schema is compatible with Calculator #001 / #002: region, freq, ambient, segment / element material codes (cu, al) and α temperature coefficients per IEC 60228. Future calculators in the series will follow the same contract.

Built-in validation tests

#	Case	Quantity	Expected	Computed	Status

Reference values cross-checked with IEEE Std 80-2013 Annex B (worked example — 70 m × 70 m square grid with rods, ρ = 400 Ω·m, ρ_s = 2500 Ω·m gravel, t_s = 0.5 s, 70 kg body) and the conductor sizing example in §11.3.