Book excerpt: Electrical Installations and Regulations focuses on the regulations that apply to electrical installations and the reasons for them. Topics covered range from electrical science to alternating and direct current supplies, as well as equipment for providing protection against excess current. Cables, wiring systems, and final subcircuits are also considered, along with earthing, discharge lighting, and testing and inspection. Comprised of 12 chapters, this book begins with an overview of electrical installation work, traits of a good electrician, and the regulations governing installations. The reader is then introduced to electrical science, with emphasis on the theory of electricity; the difference between direct current and alternating current; and the mains equipment that provide protection against excess current such as fuses and circuit breakers. Subsequent chapters focus on various types of cables; wiring systems and the regulations governing them; earthing and protection of the earthing system; and machine installation, protection, and control. Secondary batteries and systems with extra-low voltage are also described. This monograph will be of interest to electricians, electrical engineers, and students of electrical engineering courses.