For any earthing and lightning protection system to function effectively, it must be planned
strategically – beginning with design, executed through precise installation and sustained by regular maintenance. Diverse geotechnical conditions – such as high-salinity coastal zones, low-conductivity arid soils, rocky terrains and clay-rich soils – demand site-specific engineering solutions. Inappropriate material selection based on soil characteristics, coupled with improper installation and inadequate maintenance, can result in elevated earth resistance, compromised bonding integrity and reduced energy dissipation efficiency.
A. Case Study 1: Earthing System Failure at Coastal Industrial Plant
Problem Definition: Conventional pipe electrodes corroded over time in the saline environment, resulting in its elevated resistance values of 30–40 Ω.
Root Causes Identified:
- Design: Inappropriate selection of electrode and back fill material for corrosive soil.
- Maintenance: Absence of routine resistance testing and visual inspection.
Figure 1. Condition of various types of electrodes several years after installation
Proposed Solution:
- Design: To mitigate corrosion and stabilize resistance, conventional pipe electrodes were replaced with chemically treated and conductive concrete-encased electrodes.
- Maintenance: Suggested periodic resistance testing and inspections as followed by IS 3043.
Figure 1(a) shows intense corrosion of the pipe-type electrode caused by full surface contact with saline soil and salt backfill, leading to higher resistance and accelerated material degradation. Fig. 1 (b) indicates a rod-type electrode with chemical backfill, where restricted contact area minimize corrosion and extend the electrode’s lifespan in saline soil. Fig. 1 (c) indicates a rod-type electrode fully encased in concrete which effectively isolate it from saline soil, extend its lifespan and carbon particles makes concrete conductive which provides high conductivity.
The conventional pipe-type electrode may not suit the highly corrosive nature of saline soils but remains effective in less corrosive soils like clay-rich soil. This case study highlights the importance of selecting appropriate electrode and backfill materials based on soil conditions.
B. Case Study 2: Direct Lightning Strike Causing Damage
Problem Definition: A lightning strike caused damage to the DG chimney and connected electrical systems, despite the presence of an air termination rod.
Root Causes Identified:
- Installation: The air termination rod was installed below the top of chimney, leaving the upper section unprotected due to direct lightning strike. No post-installation verification or compliance audit was conducted.
Figure 2. Comparison of incorrect vs. correct installation of air termination rod on a DG chimney
Proposed Solution:
- Installation: The air termination rod was reinstalled at the correct height with proper bonding to the earthing network.
- Maintenance: A periodic inspection schedule was proposed to ensure continued system reliability.
Fig. 2(a) indicates damage from a direct lightning strike caused by improper air termination rod placement on the DG chimney, while Fig. 2(b) indicates proper lightning interception with the rod correctly installed above the DG chimney’s top edge.
Improper installation of the lightning protection system on the DG chimney resulted in significant structural and electrical damage during a lightning strike. This case study highlights the importance of following installation practices as per design and conducting post-installation testing to ensure effective protection and avoid costly failures.
C. System Life Cycle & Maintenance Strategy
As illustrated in Fig. 3, the lifecycle of an earthing and lightning protection system includes three key stages: design, installation and maintenance. As shown in Fig. 3, post-installation testing must follow relevant standards to verify system effectiveness and safety, while an integrated feedback loop supports ongoing performance improvement and enhanced reliability throughout the system lifecycle.
Conclusion
The long-term reliability of earthing and lightning protection systems relies on regular inspections, strict adherence to relevant standards, and continuous adaptation to changing environmental conditions. Ensuring sustained performance and resilience against surges, fault currents, and direct lightning strikes requires a comprehensive approach that integrates all three critical phases: design, installation, and maintenance. Each phase plays a vital role in minimizing system vulnerabilities and enhancing overall safety and operational continuity.
Elcon Engineers Pvt. Ltd. (EEPL) is a renowned engineering consultancy firm based in Vadodara, Gujarat, with a strong focus on electrical power systems. Established in 1982 by Arvind Mehta (Founder and Chairman) as a sole proprietorship, the company was restructured as a private limited entity in 1998. Contributions to this article have been made by Er. Ketul S. Prajapati, along with his team members Er. Harshal N. Gajjar and Er. Pinkesh A. Rajput from EEPL.
For more information Website: www.elconengineers.com, Email: emt@elconengineers.com
