[...]... secondary distribution from the vendors to local stores; services from store to consumer 1 2 Electrical Power Distribution Systems Figure 1-1 Typical electrical supply from generator to customer showing transformer applications and typical operating voltages The Transmission and Distribution System Figure 1-2 Typical transmission and distribution system 3 4 Electrical Power Distribution Systems In the pictorial... diameter and conductor diameter? Thickness of pipe and insulation? 7 What is electrical pressure called? 8 What are the two most important factors to be considered in determining a distribution voltage? 9 What changes in the functions of generation and transmission are due to deregulation? 10 What changes in distribution are associated with deregulation? 12 Electrical Power Distribution Systems This page... heavy conductors which are bulky and expensive to install, as well as intrinsically expensive However, there is a limit to how high the voltage may be made and how thin the conductors In overhead construction there is the problem of support-poles or towers If a conductor is made too thin, it will not be able to support itself mechanically Then the cost of additional supports and pole insulators becomes... underground In both cases, the conductor may be copper or Figure 1-6 Changes in voltage from generator to consumer All along the journey, voltage is helped down from transmission-line level to a usable level by transformers 8 Electrical Power Distribution Systems aluminum, but the insulation in the first instance is usually air, except at the supports (poles or towers) where it may be porcelain or... intentionally left blank Conductor Supports 13 Chapter 2 Conductor Supports SUPPORTS FOR OVERHEAD CONSTRUCTION Conductors need supports to get from one place to another Supports may be towers, poles, or other structures The latter may be made of steel, concrete, or wood The choice of a type of support depends on the terrain to be crossed and the size of conductors and equipment to be carried Availability... size wires 6 Electrical Power Distribution Systems carried on poles; but in the more densely built-up sections, underground conduits convey the cables, or the cable may be buried directly in the ground Distribution transformers connect to the primary distribution lines These transformers step down the primary voltage from 2400 volts, 4160 volts, or 13,800 volts, as the case may be, to approximately... transmission systems, Figure P-1 (opposite) Where additional transmission or generation was not available or too great an expense to supply some additional loads, Distributed Generation made its entry on Distribution Systems Here, small generating units usually powered by small gas turbines (although other ix units such as wind powered, solar, fuel cells, etc may be involved) are connected to the system... a typical transmission and distribution system in both pictorial and block diagram forms Although geographical difficulties, demand variances, and other reasons may make for minor differences in some transmission and distribution systems, the voltages chosen here are pretty typical This is what happens to electricity between the generator and a home, office, store, or factory There are many definitions... considerable The same is true of electrical conductors Safeguarding the life The Transmission and Distribution System 9 Figure 1-7 Practical economics affect the size of a transmission line 10 Electrical Power Distribution Systems Figure 1-8 The danger of high voltages (a) Pipe rupturing-water spills over adjacent areas; (b) Rupture of cable insulation causes arcing to other wires-sometimes causing... lines, distribution circuits, and substations specifying distinctions between them However, none of these definitions is universally applicable To give some idea of where one ends and the other begins: Transmission may be compared to bulk delivery of a commodity from factory to regional depots; subtransmission from the depot to central area warehouses; primary distribution from area warehouse to local . primary distribution from area warehouse to local wholesale vendors; secondary distribution from the vendors to local stores; services from store to con- sumer. 2 Electrical Power Distribution Systems Figure. Anthony J. Guide to electrical power distribution systems/ Anthony J. Pansini 6th ed. p. cm. Includes index. ISBN: 0-88173-505-1 (print) — 0-88173-506-X (electronic) 1. Electric power distribution. . Electricity Transmission and Distribution PDL: Primary distribution lines, ✭ indicates location of transformer stations. iii Guide to Electrical Power Distribution Systems Sixth Edition Anthony