IEEE 3003.2-2014 pdf free.IEEE Recommended Practice for Equipment Grounding and Bonding in Industrial and Commercial Power Systems.
This recommended practice covers the grounding and bonding of equipment in industrial and commercial power systems. The interconnection and grounding of the non-electrical metallic elements of a system is covered first. This is followed by a discussion of the objectives of equipment grounding. including minimizing electric shock hazard to personnel, providing adequate current carrying capability for ground faults, and ensuring the timely operation of overcurrent protection.
1.2 General
The practices set forth herein are primarily applicable to industrial, institutional, or commercial power systems.
Whcrc distances or power levels may dictate circuitry and equipment similar to a utility, consideration of utility practices is warranted. In addition to the general technical considerations in the practice of grounding as discussed in this recommended practice, as well as pertinent codes or standards imposed by local regulatory authorities, particular needs of service and the experience and training of the workforce should also be considered.
The National Electrical CodeR: (NEC), NFPA 7Oi,’ sponsored by the National Fire Protection Association, contains recommendations pertaining to system and equipment grounding applicable to industrial, commercial, and special occupancy facilities. The requirements of the NEC’ address the fundamental principlcs of safety, as does Scction 131 of lntcrnational Elcctrotcchnical Commission (IEC) Standard 603M-l. Electrical Installations of Buildings. These codes, when adopted by government entities. become mandatory. They are considered minimum requirements for the protection of life and property and should be carefully reviewed during the course of system design. The recommended practices in this document arc intended to supplement. and not negate, any of the requirements in the NEC, IEC, or any other location-specific regulatory codes.
The recommended practices in this document are intended to provide explanations of how electrical systems operate. A better understanding of the electrical principles will assist the engineer in implementing the recommendations in a manner that best provides for the needs of a specific design function.
1.3 Covered—equipment grounding and bonding
The terms grounded and bonded arc defined in the CEC, IEC. National Electrical Safety Code (NESC:i) (Accredited Standards Committee C2-20l2), and NEC. Bonding is the electrical interconnecting of conductive parts designed to achieve a low-impedance conductive path. This detinition 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 diul’ercni 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 first 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 performance of the electrical system, making it more stable and predictable. From a safety viewpoint, system grounding limits the potential diflrence 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 he isolated quickly. System grounding is covered in Chapter I of IEEE Sid l42-2OO7 (IEEE Green Bc,okT%).IEEE 3003.2 pdf free download.