The Relay Testing Handbook was created for relay technicians from all backgrounds and providesthe knowledge necessary to test most of the modern protective relays installed over a widevariety of industries. Basic electrical fundamentals, detailed descriptions of protective elements,and generic test plans are combined with examples from real life applications to increase yourconfidence in any relay testing situation. A wide variety of relay manufacturers and models areused in the examples to help you realize that once you conquer the sometimes confusing andfrustrating man-machine interfaces created by the different manufacturers, all digital relays usethe same basic fundamentals and most relays can be tested by applying these fundamentals.This package provides a step-by-step procedure for testing the most common differential protectionapplications used by a variety of manufacturers. Each chapter follows a logical progression to helpunderstand why differential protection is used and how it is applied. Testing procedures are describedin detail to ensure that the differential protection has been correctly applied. Each chapter uses thefollowing outline to best describe the element and the test procedures.1. Application2. Settings3. Pickup Testing4. Timing Tests5. Tips and Tricks to Overcome Common ObstaclesWe will review techniques to test differential relays with 3 or 6 channels so that readers can test nearlyany differential application with any modern test set.