The second edition of a bestseller, this definitive text covers all aspects of testing and maintenance of the equipment found in electrical power systems serving industrial, commercial, utility substations, and generating plants. It addresses practical aspects of routing testing and maintenance and presents both the methodologies and engineering basics needed to carry out these tasks. It is an essential reference for engineers and technicians responsible for the operation, maintenance, and testing of power system equipment. Comprehensive coverage includes dielectric theory, dissolved gas analysis, cable fault locating, ground resistance measurements, and power factor, dissipation factor, DC, breaker, and relay testing methods.

Operators, technicians, and engineers will find the information in this manual useful for gaining a basic understanding of the use and application of air valves. A valuable guide for selecting, sizing, locating, and installing air valves in water applications, M51 provides information on air valve types listed in AWWA Standard C512, latest edition, including the following: air-release valve; air/vacuum valve; and combination air valve.