Equipotential Bonding in Facilities Consisting of Different Sections

In facilities, having all grounding systems and metal parts at equipotential is just as important as the value of the grounding resistance. The concept of equipotential is extremely important to prevent fault currents from damaging points with low resistance, and to prevent system aging and corrosion risk resulting from current transitions. Unfortunately, there are some beliefs in our country that we can call superstitions. For example, installing lightning protection grounding a few meters away, or carrying out groundings separately. To give an example from the subject of lightning, a lightning strike affects an area of 2 km; performing external grounding at a point 10 or 20 meters away and not bringing it to equipotential increases the risk even more instead of preventing damage to the systems. Therefore, it is important that all groundings, metal parts, energy, and data lines in the system are at equipotential. The contrary situation is not technically correct. Equipotential must be ensured in every area we can call a facility, including Solar Power Plants, Wind Power Plants, Mass Housing, and Gas Stations. If we deepen the subject on a sectoral basis with very short examples:

• In solar power plants, the foundation grounding and ring line must reach all table legs, fences, camera systems, LED Lighting lines, inverters, transformers, and panels. There should be minimal (0.2 ohm) resistance differences in the measurement made between the 2 extreme points of the facility.
• In Gas Stations, all metal parts, canopy lines, market equipment, and panels must be brought to equipotential.
• For all facilities, lightning protection grounding must also be included in the equipotential; it must be connected to the main equipotential after an external grounding. At this connection stage, intermediate products such as Spark Gap Arresters can be used, but it is not mandatory.

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• Inside a building, local grounding areas such as data centers must be moved to the main equipotential.

• In mass housing, all building foundation groundings must be brought to equipotential with each other. Equipotential must be ensured within the sites with a ring to be formed with the rebars to be left after external grounding is done.

• In GSM and Transmitter towers, towers located side by side must also be brought to equipotential. A lightning strike falling on the side tower can damage the surrounding towers, therefore all towers must have a common ring line grounding.

The grounding of all structures and systems that have different structures but are located in the same location must be brought to equipotential.

The concept of equipotential is an indispensable complement to the 4-fold protection within the scope of the IEC 62305 standard. Grounding, LV Surge Arrester, External Lightning Protection System, and Equipotential concept are an inseparable whole. There are many types of equipotential busbars produced to provide equipotential. While the connection of metals of the same type is important, busbars with special covers can be preferred for outdoor and local equipotential bonding. As the Lightning Protection Center, we offer application, product, calculation, and measurement support regarding equipotential bonding to our customers. You can contact us for detailed information.