Earthing
Calculator
Soil resistivity aur electrode type daalo — IS 3043 ke hisaab se earth resistance aur kitne pits chahiye. Pipe, Plate, aur Rod electrode teeno ke liye.
Earth Resistance Kaise Calculate Karte Hain?
Bhai, earthing sabse zyada ignore kiya jaane wala lekin sabse important system hai site pe. Galat earthing — matlab metal body live ho sakti hai fault ke time, aur insaan ki jaan jaa sakti hai. IS 3043 India ka primary earthing standard hai jo electrode resistance calculate karne ka formula deta hai.
Pipe Electrode Formula (IS 3043)
ρ = Soil resistivity (Ω-m)
L = Electrode length (m)
d = Electrode diameter (m)
Plate Electrode Formula
A = Plate area (m²) — typically dono sides count
Plate size standard: 600x600mm (GI) ya 600x600mm (Cu)
Multiple Electrodes (Parallel)
Single electrode se target resistance nahi milta to multiple electrodes parallel mein lagate hain. Lekin simple parallel formula (R/n) use nahi karte — proximity effect ki wajah se efficiency kam hoti hai. Practical reduction factor consider karte hain.
| Number of Pits | Efficiency Factor | Effective Reduction |
|---|---|---|
| 1 pit | 100% | Baseline |
| 2 pits | ~85% | ~1.7x better |
| 3 pits | ~75% | ~2.2x better |
| 4 pits | ~68% | ~2.7x better |
| 6 pits | ~60% | ~3.6x better |
Spacing Rule
Electrodes ke beech minimum spacing 2x electrode length honi chahiye — kam spacing se “resistance area overlap” hoti hai aur combined resistance utni kam nahi hoti jitni expect karte ho.
Soil: Sandy, ρ=250 Ω-m, Pipe electrode 3m, 40mm dia
Single pit R≈83Ω → target 5Ω ke liye → 4 pits parallel, 6m spacing
Earth Conductor (GI Wire) Sizing
Fault current ke according earth conductor size select karte hain — IS 3043 mein adiabatic equation use hoti hai. Practical site rule: 25mm² GI minimum residential, 50mm²+ industrial/commercial panels ke liye.