Book excerpt: Sooner or later, power system protection is going to cost money. How much is entirely up to you. Setting up a safe and effective AC power system from the very beginning can help avoid costly downtime and repairs, provide backup power during system outages, and minimize workplace accidents. For the past 15 years, Jerry Whitaker's AC Power Systems Handbook has supplied industry professionals with a comprehensive, practical guide to the key elements of AC power for commercial and industrial systems. This third edition is thoroughly revised and completely reorganized to reflect the changing demands of modern power systems. To ease navigation, many sections are now presented as separate chapters filled with updated and expanded information. Most notably, the author adds heavily in the areas of transient suppression hardware, electrical system components, and power system fundamentals. Following a logical progression, coverage flows from power system operation to protecting equipment loads, selecting the right level of protection, grounding, standby power, and safety. Along the way, the author paints a clear picture of the sources of disturbances, the tradeoffs involved for different options, and the advantages and limitations of various approaches. Streamlined to be a hands-on, user-oriented guide, the AC Power Systems Handbook offers expert guidance on designing and installing a safe and efficient power system.