Lightning Protection
Lightning Protection (LP) is an engineered system that intercepts direct lightning strikes via air terminals, provides a low-resistance conductive path to ground, and safely disperses high-current energy (up to 200,000 amps) to prevent fire, structural collapse, equipment destruction, and personal injury.
In manufacturing and asset reliability, LP is integrated into CMMS (e.g., ServiceGrid) via standardized six-step inspection workflows: visual inspection, continuity checks, ground resistance measurement (target ≤10 Ω for NPF I/II), SPD evaluation, documentation, and post-strike protocols. Inspections are scheduled annually for high-risk (MPF I/II) assets and every 2–4 years for moderate/low risk, with immediate checks after any detected strike.
- Corrosion and degraded bonding: Unchecked corrosion at conductor joints or dissimilar metal bonding causes high-resistance points, leading to flashovers or equipment damage during strikes.
- Inadequate ground resistance: Earth electrode resistance exceeding 10 Ω (or >5 Ω for critical facilities) prevents effective current dispersal, increasing Ground Potential Rise (GPR) and risking electronic equipment failure.
- Ignored surge protection (SPD): Facilities rely only on external lightning rods while neglecting internal surge arresters, allowing indirect strikes to induce voltage surges that knock out sensitive PLCs, sensors, and data systems.
What is the maximum acceptable earth resistance for a lightning protection system in high-risk industrial zones?
≤10 Ω per IEC 62305-3 for NPF I/II; critical facilities (e.g., data centers, electronics manufacturing) often require ≤1 Ω to minimize GPR.
How does CMMS integration improve LP reliability?
CMMS enforces task sequence via mobile execution, mandates photo attachments for audit trails, automates scheduling per risk class (MPF I/II/III/IV), and triggers post-strike inspection workflows.
Why do indirect lightning strikes damage equipment more frequently than direct strikes in CMMS-monitored assets?
Indirect strikes induce electromagnetic fields that generate voltage surges on power/data lines; without bonded SPDs, these surges bypass external LP and destroy sensitive electronics.