Transformer Differential Protection | Calculating TAP Settings and Compensation Angles in SEL Relays

Download our free 28-page power system protection fundamentals text-based course: https://www.romeroengineering.co/protection-and-control-fundamentals Transformer Protection Online Course: https://www.romeroengineering.co/courses-power-system-protection-transformer-protection 87T SEL-487E Tap Calculator Spreadsheet: https://www.romeroengineering.co/downloads-87t-tap-calculator Online Courses: https://www.romeroengineering.co/courses In this video we discuss how transformer differential (87T) schemes work, using the SEL-487E protection relay as an example. We discuss how to calculate the tap settings for compensating current magnitudes, and how to determine the phase shift compensation needed for transformer differential protection schemes. We also discuss how to program an SEL-487E relay to implement a transformer differential (87T) protection scheme. Sign up to our online course membership at: https://www.romeroengineering.co/offers/FRPvBQDG/checkout Book a one-on-one training session with Ricardo: https://www.romeroengineering.co/offers/ZEo7VkVz/checkout 00:00 Intro 00:40 Example substation 02:28 Current magnitude compensation 12:04 Current phase angle compensation 15:32 Programming the SEL-487E Relay