Why Earthing Fails? 10 Real Reasons, Practical Solutions & Safety Guide

Why Earthing Fails?

Earthing failures mainly occur due to high soil resistance, poor-quality materials, dry pits, corrosion, loose joints, incorrect pit depth, and a lack of testing. To prevent earthing failure, use high-grade electrodes, maintain moisture, apply a bentonite compound, ensure a proper pit distance, perform seasonal testing, and utilize parallel multiple earthing pits to achieve stable resistance.

Introduction

Even today in the world, whether it is homes, shops, factories, schools, or hospitals, earthing failure is a major reason behind equipment damage, electric shocks, neutral-voltage fluctuations, and fire hazards.

In this post, you will learn:

✔ What earthing failure is
✔ 10 real reasons why earthing fails
✔ Practical technical solutions used by field engineers
✔ Best practices for long-life earthing
✔ Maintenance of moisture, pit design, material quality, soil condition, and testing techniques

What is Earthing Failure?

When an earthing system fails to properly discharge leakage or fault current into the ground, it is called earthing failure.

This can happen due to:

• High earth resistance
• Discontinuous current path
• Loss of moisture support
• Corroded or loose material

10 Common Reasons Why Earthing Fails (With Practical Solutions)

1. Poor Soil Resistivity (High-Ω Soil)

Hard, rocky, or dry soil naturally has high resistance.

✔ Practical Engineering Solution:

• Connect multiple pits in parallel → reduces resistance significantly.
• Use Bentonite clay or Marconite to make the soil more conductive.
• Always install the earthing pit in a moisture zone—ideally 3–6 ft below the natural wet layer.

2. Low-Quality Materials (Thin GI / Low-Grade Copper)

Cheap materials corrode quickly, increasing resistance.

✔ Practical Technique:

• For GI earthing, use at least 2.5–3 mm GI plate/pipe.
• For copper earthing, use 99.9% pure copper.
• Minimum earthing strip size → 25×3 mm GI or 16×4 mm copper.

3. Poor Backfilling Material (Incorrect Use of Salt & Charcoal)

Many people dry out the charcoal-salt mix in just a year, making the earthing ineffective.

✔ Real Field Solution:

• Use a controlled ratio of salt-charcoal (1:1).
• Modern alternative: Bentonite powder.
• For industrial sites, earthing compound gel (carbon-based) keeps resistance stable.

4. Loose Connections & Joint Failure

Bolts, nuts, and clamps rust over time, interrupting current flow.

✔ Practical Technique:

• Use hot-dip galvanized clamps for all joints.
• Every 6 months → clean, grease, and torque-check joints.
• Exothermic welding (cad welding) → best method for permanent joints.

5. Corrosion of Earthing Electrode

Moisture, chemicals, and salts can corrode GI pipes or plates.

✔ Practical Solutions:

• Apply corrosion-resistant paint or bituminous coating on pipes.
• Copper-coated rods have a life of >25 years.
• Chemical earthing rods offer the highest corrosion resistance.

6. No Moisture Support (Dry Pit)

Most common reason: the earthing pit dries out → resistance skyrockets.

✔ Practical Techniques:

• Install permanent watering inlets using PVC pipes.
• Use an automatic moisture ring system: sand, bentonite, water retention gel.
• Apply light water every 10–15 days (except during the monsoon).

7. Wrong Pit Depth & Incorrect Installation

Shallow pit → high resistance
Deep pit → stable resistance

✔ Engineering Standards:

• Minimum pit depth: 8–10 ft
• Ideal depth for rocky soil: 12–15 ft
• Always install electrodes below the permanent moisture level.

8. Earthing Not Tested Regularly

The major reason for failure: the system is left untested for years.

✔ Practical Earthing Testing:

• Use the Earth Resistance Meter (Megger) for the Fall-of-Potential test.
• Testing frequency:
  • Domestic: 1 year
  • Commercial: 6 months
  • Industrial: 3 months
• Maintaining testing records is also part of safety.

9. Improper Distance Between Earthing Pits

If two earthing pits are too close, they affect each other.

✔ Practical Rule:

• Distance between pits = depth of electrode
  • Example: 10 ft deep pit → 10 ft distance

10. Overload on the Earthing System

Many buildings use the same earthing pit for all circuits.

✔ Professional Technique:

• Create separate earthing pits for different circuits:
  • Neutral earthing
  • Body earthing
  • Lightning earthing
  • UPS earthing
• This is the most important safety rule.

⭐ Practical Tips for Why Earthing Fails

• Use Chemical Earthing for Long-Life
  • Stable resistance throughout the year
  • Often, no water is required
• Ensure Proper Mesh Earthing (Factories & Towers)
  • Copper strip grid with multiple interconnected rods
• Apply Soil Resistivity Test Before Installation
  • 4-point Wenner test → best for deciding pit location

Ideal Earthing Resistance (Recommended Values)

Final Conclusion

Earthing failure is not a minor issue—it is a silent cause of electric shocks, fire, and equipment damage.
With proper materials, correct installation, and regular testing, an earthing system can last 15–25 years without any problems.

Technical diagram showing the top reasons why earthing fails and practical solutions such as bentonite, deep pits, corrosion-free electrodes, and proper testing