Electricians install and maintain electrical systems in homes, businesses, and factories. Electricians work indoors and out, in nearly every type of facility. Almost all electricians work full time, which may include evenings and weekends. Although the work is not as dangerous as some other construction occupations, common risks include electrical shocks and burns, cuts, and falls. The trade is the newest of the traditional trades, beginning with the advent of telegraph lines in the 1800’s. In the United States, electricians are sometimes referred to as a electrical wire men as opposed to Electrical linemen, who work on electric utility company distribution systems at higher voltages. Electrical contracting is divided into four areas: commercial, residential, light industrial, and industrial wiring. Service electricians have considerable skills troubleshooting wiring problems, wiring, and making repairs. The content of this book is specifically designed for on the job use with charts, conversions, photographs, diagrams and code standards to get the job done quickly and correctly. It also serves as educational text.