Author Description

DESCRIPTION The ground system serves three primary functions which are listed below. Control Unwanted Voltage such as lightning and accidental contact with higher voltages. Establish a reliable neutral to control unbalance current. Provide an equipment ground to facilitate an overcurrent protection device when a ground fault occurs. Bond to prohibit difference of potential. PERSONNEL SAFETY Personnel safety is provided by low-impedance grounding and bonding between equipment, metallic objects, piping, and other conductive objects so that currents due to faults or lightning do not result in voltages sufficient to cause a shock or fire hazards. MAINTENANCE AND CONSTRUCTION A good ground periodic inspection and maintenance to retain its effectiveness. Continued or periodic through adequate design, choice of materials. Proper installation techniques to ensure the system must receive maintenance to resist deterioration or inadvertent destruction. EQUIPMENT AND FACILITY PROTECTION Equipment and facility 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 facility. Also, the proper operation of overcurrent protective devices is frequently dependent upon low-impedance fault current paths. ELECTRICAL NOISE REDUCTION Electrical noise reduction is accomplished on electronic circuits by ensuring that (1) minimum voltage potentials exist between power and sensitive electronic equipment, (2) the impedance between ground points throughout the facility to earth is minimal, and (3) that interference from noise sources is minimized. See Case Studies and Shielding sections for more details.