| Why We Ground ? |
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| Grounding systems have three main purpose : |
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Safety |
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- To provide a safe path for the dissipation of surge currents due to lightning or accidental contact with higher voltage system.
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Lightning Protection |
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- To Provide a path for the dissipation of electrostatic discharge currents.
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Zero Volt Reference |
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- To provide zero-volt reference for the supplied power source to the premises wiring system.
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| What is a Ground ? |
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| From the NEC- |
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A Condition connection, whether international or accident, between an electrical circuit or to some conducting body that servers in place of earth.
(Note :) It is used for establishing and maintaining the potential of the earth ( or of the conducting body ) or approximately that potential, on conductors connected to it, and for conducting ground currents to and from earth (or the conducting body). |
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| Why We Bond ? |
| Definition : NEC Article 100 and Selection 250-70 define bonding as the permanent joining of matallic parts to from an electrical continuity and the capacity to conduct safely any current that is likely to be imposed. |
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| Soil Resistivity and Ground Resistance |
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| What affects soil conductivity ? |
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Basic Soil Material |
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Soil Moisture |
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Ion-Producing Material |
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(Soluble electrolytic material) |
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Temperature |
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| Some of the Approved Methods of Grounding |
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Metallic Water Pipe |
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Metal Frame of Building |
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Ground Ring |
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Concrete Encased Electrode |
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Ground Rod Electrodes |
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Earth Plate and Lattice |
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| Why Use Exothermic Welding |
The Exothermic Connecting created a permanent, homeogreneous, and molecular bond that cannot loosen or corrode, and will carry more current that the cnductor.
The Exothermic Welding Connection are solid molecular bonds, they do not loosen or corrode over the lifetime of connection. The ame cannot be said about other methods; such as brazing, crimp, split bolt, or compreion type connections. |
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