Your facility’s lightning protection system may look exactly the way it did on installation day. The air terminals are still in place, the conductors still run from the roofline to grade, and the grounding electrodes are still buried where the drawings say they should be. From the surface, everything can appear compliant, intact, and ready for the next storm.
The problem is that the most important part of the system is also the part no one can see.
A lightning protection system depends on a continuous, low-impedance path to ground. The Lightning Protection Institute describes a complete system as a coordinated set of strike termination devices, conductors, grounding electrodes, bonding, and surge protection that safely intercepts, conducts, and dissipates lightning energy. (Lightning Protection Institute.) If the grounding system degrades, the visible roof-level components may still look correct while the actual path to earth becomes less reliable.
Grounding electrodes live in an aggressive environment. Soil chemistry, moisture, microbial activity, stray currents, and seasonal changes can all accelerate corrosion or change the electrical behavior of the grounding system. A published review of grounding grid corrosion found that corrosion reduces conductor cross-sectional area and can increase grounding resistance over time, which directly affects the safety function of grounding systems. (PMC.)
That slow drift creates a practical maintenance problem. A facility may pass a visual inspection while its ground resistance has already moved outside the range needed for reliable lightning protection performance. Visual checks can identify damaged conductors, missing bonds, or obvious corrosion, but they cannot tell a facility manager whether buried grounding electrodes still provide the intended resistance value.
Standards and industry guidance make those resistance values important. A ground resistance guide from HVHiPot summarizes common targets, including 25 ohms for many general electrical grounding applications, lower targets for lightning protection systems, and formal test methods such as IEEE 81 for measuring resistance. (HVHiPot.) The exact threshold depends on the system, site, and applicable standard, but the operational reality is the same: grounding performance must be measured, not assumed.
This is where calendar-based maintenance falls short. An annual inspection captures one moment in time. It may happen after a wet season, before a dry season, before nearby construction changes the electrical environment, or long before a hidden connection begins to fail. For critical facilities, that point-in-time model leaves too much uncertainty between inspections.
Continuous ground resistance monitoring changes the maintenance model from “inspect and hope” to “measure and respond.” Instead of waiting for the next annual visit, a monitoring device can track grounding system condition over time, detect degradation trends, and give the facility team earlier warning that the system needs attention. Strategic Market Research describes smart grounding and monitoring systems as a growing segment for critical infrastructure, with monitoring and smart grounding gaining traction as facilities move away from install-and-forget models. (Strategic Market Research.)
The business case is strongest where downtime is expensive. Industrial plants, telecom facilities, data centers, hospitals, energy assets, and government sites cannot treat lightning protection as a passive asset that is checked once and then forgotten. These facilities need evidence that the system is ready before the storm, not proof that it failed afterward.
That is the role of the GRM 2500™ within VFC’s LightningLink™ smart protection system. The GRM 2500™ is positioned as the ground resistance monitoring component of the system, while StrikeSense™ detects lightning events and the Lyncole Smart Monitor Portal provides visibility into system condition. (vfclp.com/smart-protection). Together, those components create a smarter maintenance loop: monitor grounding integrity, detect events, review data, document status, and take action before risk becomes loss.
For facility teams, the first step is simple. Review the last documented ground resistance test, compare it against the applicable standard and facility risk profile, and ask whether the current inspection interval is adequate for the facility’s consequence of failure. If the answer is uncertain, the next question is not whether the lightning protection system looks intact. The next question is whether its grounding path is being measured often enough to trust.
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