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WHAT IS GROUNDING

There are several important reasons why a grounding system should be installed. But the most important reason is to protect people! Secondary reasons include protection of structures and equipment from unintentional contact with energized electrical lines. The grounding system must ensure maximum safety from electrical system faults and lightning.

A good grounding system must receive periodic inspection and maintenance, if needed, to retain its effectiveness. Continued or periodic maintenance is aided through adequate design, choice of materials and proper installation techniques to ensure that the grounding system resists deterioration or inadvertent destruction. Therefore, minimal repair is needed to retain effectiveness throughout the life of the structure.

The grounding system serves three primary functions which are listed below.

PERSONNEL SAFETY:


Personnel safety is provided by low impedance grounding and bonding between metallic equipment, chassis, piping, and other conductive objects so that currents, due to faults or lightning, do not result in voltages sufficient to cause a shock hazard. Proper grounding facilitates the operation of the overcurrent protective device protecting the circuit.

EQUIPMENT AND BUILDING PROTECTION:

Equipment and building protection is provided by low impedance grounding and bonding between electrical services, protective devices, equipment and other conductive objects so that faults or lightning currents do not result in hazardous voltages within the building. Also, the proper operation of overcurrent protective devices is frequently dependent upon low impedance fault current paths.

ELECTRICAL NOISE REDUCTION:

Proper grounding aids in electrical noise reduction and ensures:

1. The impedance between the signal ground points throughout the building is minimized.
2. The voltage potentials between interconnected equipment are minimized.
3. That the effects of electrical and magnetic field coupling are minimized.

Another function of the grounding system is to provide a reference for circuit conductors to stabilize their voltage to ground during normal operation. The earth itself is not essential to provide a reference function. Another suitable conductive body may be used instead.

The function of a grounding electrode system and a ground terminal is to provide a system of conductors which ensures electrical contact with the earth.

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