IEEE Std 3003.2 pdf free download
IEEE Std 3003.2 pdf free download.Equipment Grounding and Bonding in Industrial and Commercial Power Systems.
The terms grounded and bonded are defined in the CEC, IEC, National Electrical Safety Code (NESC) (Accredited Standards Committee C2-2012), and NEC. Bonding is the electrical interconnecting of conductive parts designed to achieve a low-impedance conductive path. This delinition is self-explanatory and implies that the conductive path should be adequately sized, and connections properly installed, in order to maintain a path with impedance as low as possible. The term bonding obviously is not exclusive to grounded systems. Grounded means connected to, or in contact with, the earth, or connected to some extended conductive body that serves in place of the earth, whether the connection is intentional or accidental. The earth or the other conductive body is known as the ground in North America and areas of the world that use the CEC or NEC, and earth in the areas of the world that use the IEC. When used as a verb, grounding is the act of establishing the aforementioned connection to ground or the conductive body. When used as an adjective, grounding describes the conductor or metal part that is used to make the connection to ground.
There are two different types of permanent grounding relative to electrical work. One type enhances the safety of the electrical system, and the second enhances the safety of the electrical equipment. The tirst type is system grounding. System grounding is attaching at least one point of the normal current-carrying electrical path-to-ground, either solidly or through an impedance. The system ground affects pertiirmance of the electrical system, making it more stable and predictable. From a safety viewpoint, system grounding limits the potential difference between uninsulated objects in an area, helps limit the magnitude of overvoltages due to transients, and provides the reference point for the return of fault currents so that faults can be isolated quickly. System grounding is covered in Chapter 1 of IEEE Std l42ThI2OO7 (IEEE Green BookT%1).
The second type is equipment grounding, which provides significant protection for the electrical equipment and for any people in close proximity to it. Equipment grounding is the act of bonding all non-currentcarrying conductive objects together to create a low-impedance conductive path (or body) to the source, which is connected to the system ground. In NEC terminology, these functions are performed by the equipment grounding conductor (EGC), and in LEC terminology by the protective earth (PE) conductor. In this document, the term protective conductor will be used in place of the NEC term or the TEC term in order to stress that these dual functions of grounding and bonding are being done for safety purposes. Grounding and bonding will also be used throughout this document as appropriate.Electric shock injuries result from contact with metallic components that are energized, whether intentionally or unintentionally. Effective equipment grounding and bonding practices can minimize these personal injuries. A breakdown of basic insulation can cause accidental contact between an energized electrical conductor and the metal frame that encloses it. Such contact will energize the frame to the voltage level of the conductor. Safety considerations require that the level of the shock-hazard voltage be minimized as much as possible to a less hazardous level. The equipment grounding and bonding system should do this by forming a low-impedance path back to the source and thereby facilitating the operation of the circuit protective device. The impedance of the protective conductor should be low enough to accept the available line-to-ground- fault current without creating a hazardous voltage drop across the conductor. Therefore, the available ground-fault current of the supply system will have a direct bearing on the protective conductor requirements.IEEE Std 3003.2 pdf download.
