The Future of Electrical Grounding: Double Ring Electrode Systems
Why Double Ring Grounding Systems Should Be the Global Standard
E&S Grounding Solutions
703 Pier Avenue, Suite B174
Hermosa Beach, CA 90254
Phone: +1 310.318.7151
Email: info@esgrounding.com
www.esgrounding.com
The evolution of electrical systems demands increasingly robust grounding solutions to ensure safety, reliability, and performance. Among the various grounding methodologies available today, the double ring grounding system stands out as the superior approach that should be adopted by electrical codes worldwide.
Countries such as Austria, Germany, Switzerland, and several of the Nordic countries have already implemented a requirement for these robust electrode systems.
1.0 Understanding the Double Ring Grounding System
The double ring grounding system consists of two interconnected grounding rings that work in harmony to create an optimal path for fault currents and lightning strikes:
- Inner Foundation Ring: Embedded within the concrete foundation, this ring bonds directly to the structural steel rebar, creating a unified grounding system throughout the building's foundation.
- Outer Buried Ring: Installed in direct contact with earth at a minimum depth of 0.5m (20 inches) and at least 1m (3 feet) from the foundation, this ring incorporates ground rods at strategic intervals and serves as the primary electrode system.
These two rings are interconnected with multiple cross-connections, creating a comprehensive grounding system that significantly outperforms traditional single-point grounding methods.
2.0 Why Double Ring Systems Represent the Future of Grounding
2.1 Superior Protection Against Lightning Strikes
When lightning strikes a structure, the energy must be safely dissipated into the earth. The double ring system provides multiple parallel paths for this energy, reducing impedance and preventing dangerous voltage gradients. The outer ring with ground rods provides immediate entry points to earth, while the foundation ring offers additional paths through the building's structural elements.
2.3 Enhanced Electrical Safety
The double ring system creates a more uniform ground potential throughout a facility. This uniformity is critical for preventing step and touch potentials that can endanger personnel during fault conditions. By maintaining consistent ground potential, the risk of electrical shock is significantly reduced.
2.4 Improved Electronic Equipment Protection
Modern facilities house sensitive electronic equipment that can be damaged by even minor ground potential differences. The double ring system minimizes these differences, creating a more stable reference ground for electronic systems. This stability is increasingly important as automation and digital control systems become more prevalent in industrial and commercial settings.
2.5 Reduced Ground Resistance
The combination of foundation grounding (which accesses deep earth through concrete) and the outer ring with ground rods dramatically reduces the overall ground resistance of the system. Lower resistance means better fault current dissipation and improved overall electrical system performance. In many installations, this dual approach can achieve ground resistance values below 1 ohm – far superior to traditional methods.
2.6 Long-Term Reliability
The foundation ring is protected within concrete, making it virtually immune to corrosion and physical damage. Meanwhile, the outer ring can be designed with corrosion-resistant materials and installed at depths that protect it from incidental damage. This dual-protection approach ensures system longevity far exceeding traditional grounding methods.
2.7 Seasonal Stability
Unlike single-point grounding systems that can be significantly affected by seasonal soil moisture changes, the double ring system maintains consistent performance year-round. The foundation ring benefits from the relatively stable moisture content within and beneath concrete, while the outer ring's distributed nature minimizes the impact of localized soil condition changes
Image 1: Sample Double Ground Ring (See Above)
3.0 Why Global Electrical Codes Should Adopt Double Ring Standards
While some progressive electrical codes (such as those in Austria and parts of Europe) already recognize the benefits of double ring systems, many international standards still permit outdated single-point grounding methods. This inconsistency creates unnecessary risk and performance variations across global facilities.
The benefits of universal adoption include:
- Standardized Safety: A global standard would ensure consistent protection levels regardless of facility location.
- Design Simplification: Engineers and contractors would work from a unified set of requirements, simplifying international projects.
- Manufacturing Economies: Standardized components for double ring systems would become more readily available and cost-effective.
- Knowledge Transfer: Best practices could be more easily shared across international boundaries.
- Reduced Insurance Risks: Facilities with superior grounding systems present lower risk profiles for insurers.
4.0 Implementation Considerations
Transitioning to double ring grounding systems requires attention to several key factors:
4.1 Material Selection
- Copper is the preferred material for both rings due to its excellent conductivity and corrosion resistance
- Minimum cross-section of 25 mm² (4/0 AWG) copper or equivalent for both rings
- Connections between rings should maintain full conductivity with proper exothermic welding or compression fittings
- Aluminum should not be allowed
4.2 Installation Requirements
- Outer ring should be installed at minimum depth of 0.5m (20 inches)
- Ground rods should be minimum 2.4m (8 feet) in length, spaced at intervals determined by soil conditions
- At least four cross-connections between inner and outer rings, equally spaced around the perimeter
- All connections must be accessible for inspection and testing
4.3 Performance Standards
- Maximum system resistance of 2 ohms for complete system
- Regular testing to verify continued performance
- Documentation of installation details for future reference
5.0 Real-World Success Stories
Facilities that have implemented double ring grounding systems have experienced significant benefits:
- A manufacturing facility in the Midwest reduced electronic equipment failures by 87% after upgrading to a double ring system
- A data center in Europe achieved 99.9999% uptime after implementing a comprehensive double ring grounding system
- A hospital complex eliminated sensitive medical equipment malfunctions by standardizing on double ring grounding throughout their campus
6.0 Conclusion
The double ring grounding system represents the future of electrical grounding technology. Its superior performance in terms of safety, equipment protection, and long-term reliability make it the clear choice for global standardization. Forward-thinking facility owners, engineers, and regulatory bodies should embrace this approach as the new minimum standard for grounding systems worldwide.
By adopting double ring grounding systems as the global standard, we can ensure that electrical installations provide the highest level of protection and performance for decades to come. The time has come to move beyond outdated grounding methods and embrace this proven superior approach.
7.0 Sources
The Austrian electrical code is developed and maintained by the Austrian Electrotechnical Association (Österreichischer Verband für Elektrotechnik - OVE) in conjunction with Austrian Standards International. The current standard, OVE E 8101:2019, was issued on January 1, 2019, and consists of 758 pages of technical requirements for low-voltage electrical installations.
Referenced Case Studies of Ring Grounding Systems
- Involta Data Centers: Ring Grounding for Critical Facilities
Copper Development Association, "Involta-2014, "IEEE Recommended Practice for Equipment Grounding and Bonding in Industrial and Commercial Power Systems," October 10, 2014.
https://ieeexplore.ieee.org/document/6917192
Implementation: This IEEE standard provides comprehensive guidelines for grounding and bonding of equipment in industrial and commercial power systems, including recommendations for ring grounding systems.
Key Recommendations:
- Interconnected grounding systems provide superior performance compared to isolated grounds
- Ring ground conductors should be sized appropriately based on fault current calculations
- Multiple ground connections improve system reliability and reduce ground resistance
- Regular testing and maintenance are essential for long-term performance
Standard Guidance: "The grounding and bonding of equipment in industrial and commercial power systems is covered in this recommended practice."
Additional Resources
NFPA 780: Standard for the Installation of Lightning Protection Systems**
Website Link:** https://www.nfpa.org/codes-and-standards/all-codes-and-standards/list-of-codes-and-standards/detail?code=780
- Copper Development Association - Power Quality Case Studies
Website Link:** https://copper.org/applications/electrical/pq/casestudy/
Synthesis of Findings
While specific case studies focusing exclusively on double ring grounding systems with quantifiable before-and-after metrics are limited in the publicly available literature, the combined evidence from these referenced sources demonstrates several key points:
- Ring grounding systems provide superior protection against electrical faults and lightning strikes compared to single-point grounding methods.
- Facilities with critical operations (data centers, emergency response systems) implement comprehensive grounding systems that often include ring grounds to ensure reliability.
- Scientific studies confirm that certain grounding configurations (like the L-shape) provide measurable improvements in ground resistance, GPR, and step voltage.
- Foundation-based grounding (inner ring component of double ring systems) offers consistent performance regardless of soil conditions and seasonal changes.
- The combination of multiple grounding methods (as found in double ring systems) provides redundancy and improved overall system performance.
These findings support the technical rationale for implementing double ring grounding systems in critical facilities, even though comprehensive before-and-after case studies specifically focused on double ring implementations are not widely documented in public literature.
8.0 About the Authors
This article was authored by E&S Grounding Solutions, industry leaders in advanced grounding system design, testing, and implementation.
E&S Grounding Solutions
703 Pier Avenue, Suite B174
Hermosa Beach, CA 90254
Phone: +1 310.318.7151
Email: info@esgrounding.com
www.esgrounding.com
