ABSTRACT
Electricity in the modern society is the most convenient and useful form of energy transfer and use, being an efficient energy vector that carries over long distances with minimum impact over the transfer areas and at the place of end-use. Building or facility power distribution is accomplished through electric services, wiring, protection devices, and methods. Electric services, feeders, branch circuits, and panelboards are critical and essential components of building power distribution. Panelboards, switchboards, feeders, branch circuits, and associated fittings and devices are important components of power distribution inside buildings, industrial, and commercial facilities. Cables are usually contained in raceways, conduits, or cable trays, protecting them from damage and interference. In addition to structural requirements, when designing cable tray systems, the electrical requirements must also be carefully considered, to ensure compliance with the specifications and requirements of codes and standards. This chapter explores the characteristics of branch circuits, feeders, cables, cable trays, raceways, grounding, and protection devices. Several standards and guidelines exist for the design of cable tray systems (e.g., National Electric Code [NEC], National Electrical Manufacturers Association [NEMA], and International Electrotechnical Commission [IEC] specifications). The function of a protection device is to limit excessive currents in a circuit or equipment that could result in permanent damages, malfunction to other circuits, damage to equipment, or threats to personal safety. The chapter gives a comprehensive presentation of faults, electrical protection systems in buildings, protective devices, grounding, feeder design, and branch circuits for lighting equipment, electric systems, and electrical motors.
