| 1 | Soil Resistivity | Determine how easily fault current can disperse through the soil. Soil resistivity is commonly measured in ohm-metres using a field test. | Ground rods, tape electrodes, buried ring conductors, inspection pits and test links. | Use a larger or longer electrode system, or multiple bonded electrodes, where high-resistivity soil makes the target resistance difficult to achieve. Final electrode layout should be based on measured results and the applicable electrical code. | Four-point soil-resistivity testing and post-installation earth resistance testing. |
| 2 | Available Fault Current | Review the prospective fault current, protective-device clearing time and the thermal withstand requirement of the grounding conductors. | Main grounding conductors, bonding jumpers, compression connectors, mechanical clamps and grounding bars. | Size conductors and connectors for the expected fault duty and installation environment. Connections must remain mechanically secure until protective devices clear the fault. | Short-circuit study, conductor sizing review and visual inspection of connections. |
| 3 | Electrode Material and Compatibility | Identify the electrode material and check for galvanic or chemical interaction between dissimilar metals. | Listed clamps, exothermic or irreversible compression connections, bimetallic connectors and compatible grounding bars. | Use connectors specifically approved for the electrode and conductor materials. Avoid direct contact between incompatible metals unless a suitable transition connector is provided. | Material certificates, connector markings and installation inspection. |
| 4 | Corrosive Soil or Chemical Exposure | Check soil pH, salt content, industrial chemicals, wastewater exposure and areas subject to persistent moisture. | Corrosion-resistant conductors, sealed inspection pits, protective coatings and compatible corrosion-resistant clamps. | Select materials and coatings appropriate for the measured or documented exposure. Do not rely on coatings where the connection must maintain a permanent low-impedance path unless the connection method is approved for that use. | Environmental assessment, periodic visual inspection and continuity testing. |
| 5 | Rocky, Shallow or Congested Ground | Identify drilling restrictions, buried utilities, foundations, underground services and the depth of usable soil. | Horizontal counterpoise conductors, ground plates, multiple shorter electrodes, bonding conductors and accessible test points. | Adapt the electrode geometry to the available area while maintaining safe separation from utilities. Coordinate the layout with civil and electrical drawings before excavation. | Utility-location survey, installation records and resistance testing. |
| 6 | Frost, Dry Seasons and Seasonal Moisture | Consider seasonal changes in soil moisture and the local frost depth, because frozen or very dry soil can increase measured resistance. | Deep-driven electrodes, buried ring conductors, protected test wells and flexible bonding connections. | Place electrodes below the local frost-affected zone where practical and account for seasonal soil conditions in the design. Do not use temporary watering as a permanent grounding solution. | Seasonal resistance measurements and review of local geotechnical conditions. |
| 7 | Lightning and Surge Exposure | Determine whether the structure includes lightning protection, overhead lines, sensitive electronics or frequent surge exposure. | Short, straight bonding conductors, equipotential bonding bars, test joints, lightning down-conductor connectors and surge protective device bonding conductors. | Minimize conductor length and sharp bends, bond metallic systems where required, and coordinate the grounding arrangement with the lightning and surge-protection design. | Visual routing inspection, continuity testing and review of bonding details. |
| 8 | Equipotential Bonding Needs | Identify exposed conductive parts, structural steel, metallic piping, cable trays, tanks and other systems that may introduce different touch potentials. | Equipotential bonding bars, bonding clamps, flexible braids, bonding jumpers and labeled test links. | Bonding conductors should be routed and sized according to the governing code and fault conditions. Connections must be accessible where inspection or testing is required. | Continuity testing between bonded parts and inspection of conductor routing. |
| 9 | Mechanical Damage and Accessibility | Assess vehicle traffic, construction activity, vibration, impact risk, public access and the likelihood of unauthorized disturbance. | Protective conduits, guarded ground bars, recessed inspection pits, lockable covers and strain-relief fittings. | Protect exposed conductors and connections from impact, abrasion and unauthorized access while keeping test points reachable for qualified personnel. | Physical inspection, cover and enclosure checks, and torque verification where specified. |
| 10 | Testing, Documentation and Maintenance | Confirm that the system can be isolated, tested and maintained without compromising permanent protective bonding. | Removable test links, labeled grounding bars, inspection chambers, permanent identification tags and test terminals. | Provide clear records of electrode locations, conductor sizes, connection methods and test results. Use qualified personnel and follow the applicable local electrical and safety requirements. | Continuity, earth resistance and, where applicable, clamp or fall-of-potential testing with documented results. |
